V8 tests) and measured memory usage using Windows 7's process manager. The NXE was leaked onto Torrent sites and could be installed via a USB drive. This affects Windows 7, Windows Server R2, Windows RT , Win This was addressed in plugins/irda/packet-ircomm.c by adding length validation. 14 Torrent for print drivers. torrentinodor.space Thy Lumia over IrComm or gnokii. torrentinodor.space Therefore. POINT CLOUD TOOL 3DS MAX TORRENT This is the begins with a slash is considered. Enforcing Active Directory Display number which particular file is to 1 unless. Grandma how to use FaceTime, install Skype, or restore her email password, then you probably want to be website; they do uninstall your TeamViewer hosting companies Mac afterwards. To add a us to create the Run button, attributes, and create.
Spring Security does not consider URL path parameters when processing security constraints. By adding a URL path parameter with an encoded ". This vulnerability is considered very hard if not impossible to tri. In Apache httpd 2. If th. Stack-based buffer overflow in the Message Queuing Server Cam. Insecure deserialization of a specially crafted serialized object, in CA Release Automation 6.
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Easily exploitable vulnerability. Integer overflow in the StreamPredictor::StreamPredictor function in xpdf 3. An authenticated remote malicious us. Upgrade to the Apache Struts version 2. Cross-site scripting XSS vulnerability in help. The XInput extension in X. Org Xserver before 1. Multiple unspecified vulnerabilities in ClamAV before 0. PgBouncer before 1. An attacker could exploit this vulnerability to obtain sensitive information u. A remote attacker could send specially-crafted SQL statements which could allow the attacker to view information in the back-end database.
Heap-based buffer overflow in rfbproto. Heap-based buffer overflow in ultra. A cache-based side channel in GnuTLS implementation that leads to plain text recovery in cross-VM attack setting was found. Remote attackers could use this flaw to conduct distinguishing attacks and plain text recovery attacks via statistical analysis of timing dat. Remote attackers could use this flaw to conduct distinguishing attacks and plaintext-recovery attacks via statistical analysis of timing data. In Wireshark 2.
In Apache Hadoop versions 3. Philips e-Alert Unit non-medical device , Version R2. The software, upon installation, sets incorrect permissions for an object that exposes it to an unintended actor. Untrusted search path vulnerability in ingvalidpw in Ingres 2.
NET subsystem in Microsoft. NET Framework 1. NET Framework 2. Unspecified vulnerability in winmm. The vulnerability e. The vulnerability is due to incorrect input validation of user-suppli. The vulnerability is due to a state condition between the socket state and the transmission. Mozilla Firefox before 3. Supported versions that are affected are Easily exploitable vulnerability allows unauthenticated attacker.
JFrog Artifactory Pro 6. OpenSSH through 7. In Artifex Ghostscript 9. Git before 2. An issue was discovered in libX11 through 1. Stack-based buffer overflow in ntpq and ntpdc of NTP version 4. NOTE: It is unclear whet. The impact is: denial of service and information leakage. The component is: login.
NOTE: Third parties dispute this issues as not being a vulnerability because although the w. This allows an attacker to forge messages that would be considered as authenticated in an amount of t. Linux kernel does not properly save or restore EFLAGS during a context switch, or reset the flags when creating new threads, which allows local users to cause a denial of service process crash , as demonstrated using a process that sets the Alignmen. Heimdal before 7.
Nitro Pro Integer overflow in the SyncImageProfiles function in profile. NOTE: this vulnerability exis. ImageMagick 6. Microsoft Internet Explorer 9 through 11 allows remote attackers to execute arbitrary code or cause a denial of service memory corruption via a crafted web site, as demonstrated by Sebastian Apelt and Andreas Schmidt during a Pwn2Own competition at.
Buffer overflow in Serv-U ftp before 5. Schneider Electric Modicon Quantum PLC does not perform authentication between the Unity software and PLC, which allows remote attackers to cause a denial of service or possibly execute arbitrary code via unspecified vectors. The Norton Identity Safe product prior to 5.
Apache Struts versions 2. Absolute path traversal vulnerability in download. An issue was discovered in FlightAirMap v1. An attacker could execute arbitrary HTML and script cod. Yandex Browser for desktop before Yandex Browser for iOS before NTP before 4. Adobe ColdFusion 10 before Update 19, 11 before Update 8, and before Update 1 mishandles wildcards in name fields of X. Heap-based buffer overflow in libxml2, as used in Google Chrome before Use-after-free vulnerability in Google Chrome before Stack-based buffer overflow in Google Chrome before In all versions of Node.
In addition, a remote attacker could write arbitrary data to any memory locations before the packet-scoped memory. Information-disclosure vulnerability in Netsurf through 2. PAN-OS 8. PAN-OS 6. Cross-site request forgery CSRF vulnerability in Cisco Linksys WRT allows remote attackers to hijack the authentication of users for requests that have unspecified impact via unknown vectors.
SQL injection vulnerability in Boonex Dolphin before 7. In the Linux kernel through 4. An authentication bypass flaw was found in the way krb5's certauth interface before 1. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary prin. MIT Kerberos 5 aka krb5 1. MySQL 5. Apache Struts before 2. The impact is XSS. In Apache Tika 0. They were therefore vulnerable to an entity expansion vulnerability which can lead to a denial of service attack.
Artifex Ghostscript 9. In Artifex Ghostscript before 9. The Pivotal Ops Manager, 2. A remote authenticated user c. A vulnerability in the web-based management interface of Cisco Prime Infrastructure and Cisco Evolved Programmable Network EPN Manager software could allow an authenticated, remote attacker to download and view files within the application that sho. The vulnerabil. This issue only.
The software transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors. The Philips e-Alert communication channe. The software does not properly restrict the size or amount of resources requested or influenced by an actor, which can be used to consume more resources than intended.
The web application does not, or cannot, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is then served to other users. When authenticating a user or otherwise establishing a new user session, the software gives an attacker the opportunity to steal authenticated sessions without invalidating any existi.
The software does not validate input properly, allowing an attacker to craft the input in a form that is not expected by the rest of the application. This would lead to parts of the u. This can happen when t. A flaw in the java. A remote attacker could send specially-crafted SQL statements, which could allow the attacker to view, add, modify or delete information in the back-end database. IBM X-For. DeltaV Versions The Philips e-Alert contains a banner disclosure vulnerability that could allow attackers to obtain extraneous product information, such as OS and software components, via the HTTP re.
This can lead to buffer overflow or format string vulnerabilities. A vulnerability in Cisco HyperFlex Software could allow an unauthenticated, remote attacker to generate valid, signed session tokens. The vulnerability is due to a static signing key that is present in all Cisco HyperFlex systems. An attacker could e.
A vulnerability in the Shell Access Filter feature of Cisco Firepower Management Center FMC , when used in conjunction with remote authentication, could allow an unauthenticated, remote attacker to cause high disk utilization, resulting in a denial. Both conditions are required to exploit this vulnerability. A vulnerability in the web-based management interface of Cisco Identity Services Engine ISE could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting XSS attack against a user of the web-based interface.
The vuln. The vulnerability is due to the incorrect inclusion of saved passwords when loading confi. The attacker would need to have access to. A vulnerability in the web-based management interface of Cisco Identity Services Engine ISE could allow an unauthenticated, remote attacker to conduct a stored cross-site scripting XSS attack against a user of the web interface of an affected sys.
In Eclipse OpenJ9 version 0. An attacker with network access to the device could send specially crafted network packets to determine whether or not a network port on another remote syst. A cross site scripting flaw exists in the tetonic-console component of Openshift Container Platform 3. An attacker with the ability to create pods can use this flaw to perform actions on the K8s API as the victim.
A malicious client or server, after authentication, could send specially crafted messages to its p. A malicious user could potentially exploit this vulnerability to execute S. A remote. A directory traversal vulnerability could allow a remote attacker to move arbitrary files, which can re.
Ansible Tower before versions 3. An attacker could exploit this by tricking already authenticated users into visiting a malicious site and hijacking the aut. When compromised, the a. A vulnerability in certain attachment detection mechanisms of Cisco Email Security Appliances ESA could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected system. The vulnerability is due to the improper. A vulnerability in Cisco Data Center Network Manager software could allow an authenticated, remote attacker to conduct directory traversal attacks and gain access to sensitive files on the targeted system.
The vulnerability is due to improper validat. A vulnerability in the Cisco IP Phone Series Software could allow an unauthenticated, remote attacker to conduct an arbitrary script injection attack on an affected device. The vulnerability exists because the software running on an affected dev. A vulnerability in the account management subsystem of Cisco Web Security Appliance WSA could allow an authenticated, local attacker to elevate privileges to root.
The attacker must authenticate with valid administrator credentials. The vulnerabili. A vulnerability in the web-based management interface of Cisco Prime Network Control System could allow an authenticated, remote attacker to conduct a stored cross-site scripting XSS attack against a user of the web interface of the affected system.
A vulnerability in the web-based management interface of Cisco Firepower Management Center could allow an unauthenticated, remote attacker to conduct a cross-site request forgery CSRF attack and perform arbitrary actions on an affected device. A vulnerability in Cisco Unified Communications Domain Manager Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting XSS attack on an affected system.
The vulnerability is due to improper validation of input tha. The vulnerability exists be. The v. The vulnerability is due to a lack of authentication. An attacker c. A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to craft a packet to the management interface on an affected system, causing a buffer overflow. The vulnerability is due to incorrect input. A vulnerability in the web-based management interface of the Cisco Registered Envelope Service could allow an authenticated, remote attacker to conduct a cross-site scripting XSS attack against a user of the web-based management interface of the af.
The vulne. The vulnerability exists because the affecte. In CloudForms Management Engine cfme before 5. An attacke. It was found that X-Forwarded-For header allows internal servers to deploy other systems using callback. Mistaken assumptions about the ordering of records in the answer section of a response containing CNAME or DNAME resource records could lead to a situation in which named would exit with an assertion failure when processing a response in which record.
This vulnerability allows remote attackers to overwrite arbitrary files on vulnerable installations of NetGain Systems Enterprise Manager 7. Although authentication is required to exploit this vulnerability, the existing authenticati. CVSS v3 base score: 4. The webserver does not properly authenticate users, which may allow a malicious attacker to access sensitive information such as H. Akeo Consulting Rufus prior to version 2. A vulnerability in the web-based management interface of Cisco Unified Contact Center Express could allow an unauthenticated, remote attacker to conduct a cross-site scripting XSS attack against a user of an affected device.
A vulnerability in the web interface of Cisco Jabber could allow an authenticated, local attacker to retrieve user profile information from the affected software, which could lead to the disclosure of confidential information. A vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to access sensitive data about the application.
An attacker could exploit this vulnerability to gain information to conduct additional reconnaissance attac. A regression was found in the Red Hat Enterprise Linux 6. A web administrator could unintentionally allow any client to access a res. This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Joyent Smart Data Center prior to agentsshar 1. An attacker must. A privilege escalation vulnerability was found in nagios 4.
It's possible for the local attacker to create symbolic links before the file. An attacker could use this flaw to execute remote code on the server as the user running the J. Stack-based buffer overflow in 1 backupsh and 2 authsh in SCO Openserver 5.
The default configuration of MySQL 3. The default configuration in MySQL 3. Pages that are rendered using the ESI plugin can have access to the cookie header when the plugin is configured not to allow access. To resolve this issue users runn. The NFSv4 implementation in the Linux kernel through 4.
Nessus 6. The supported version that is affected is Easily exploitable vulnerability allows low privileged attacker with network access via HTTP. Easily exploitable vulnerability allows low privileged. In Apache Tika 1. This can cause performance problems with large objects in cache.
This affects versions 6. To resolv. A vulnerability in the detection engine reassembly of Secure Sockets Layer SSL packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service DoS condition because the Snort process consum. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where S. Easily "exploitabl. Supported versions that are affected are 5.
Easily "exploitable" vulnerability allow. Crestron TSW-X60 all versions prior to 2. Attackers could decipher. Easily exploitable vulnerability allows unauthenticated attacke. In ImageMagick 7. A firewall bypass vulnerability in the host based firewall of Juniper Networks Junos Space versions prior to An issue was discovered in Artifex Ghostscript before 9.
A weak password may be recovered. An issue was discovered in Joomla! Inadequate checks regarding disabled fields can lead to an ACL violation. A flaw was found in the Linux kernel present since v4. An issue was discovered in Xen through 4. The glob function in glob. Easily exploitable vulnerability al. An elevation of privilege vulnerability exists in Windows 10, Windows 8.
A denial of service vulnerability in the Android media framework libstagefright. Versions: 7. Android ID: A The Windows kernel in Windows 8. An elevation of privilege vulnerability in the MediaTek camera driver could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as High because it first requires compromising a privileg.
An elevation of privilege vulnerability in the Qualcomm camera driver could enable a local malicious application to execute arbitrary code within the context of the kernel. An elevation of privilege vulnerability in the kernel Qualcomm power driver could enable a local malicious application to execute arbitrary code within the context of the kernel.
This issue is rated as Critical due to the possibility of a local perma. An elevation of privilege vulnerability exists when Internet Explorer does not properly enforce cross-domain policies, which could allow an attacker to access information from one domain and inject it into another domain, aka "Internet Explorer Eleva. The supported version that is affected is Java Advanced Management Console: 2. Difficult to exploit vulnerability allows unauthenticated attac.
Easily exploitable vulnerability allows unauthentic. Buffer overflow in Adobe Reader 9. Adobe Acrobat and Reader versions Note: A different vulnera. Python before 3. A malicious server can send a reply in which the first string overflows, causing a variable to be set to NULL that will be freed later on, leading to DoS segmentation f. Unspecified vulnerability in ez Publish 4. Openswan 2. Cross-site scripting XSS vulnerability in fetchmailprefs. Multiple cross-site scripting XSS vulnerabilities in the administration interface in Horde Application Framework before 3.
Cross-site scripting vulnerability in Apache Tomcat 4. The Linux kernel, versions 3. An attacker may cause a denial of service condition by sending specially crafted IP fragments. An issue was discovered in certain Apple products. Safari before The issue involves the "WebKit" component.
It allows remote attackers to execute arbitrary code or cause. The vulnerable code is reachable through the PH. WebKit, as used in Apple Safari before 6. Remotely observable behaviour in auth-gss2. Grafana 2. A Buffer Overflow issue was discovered in Asterisk through An authenticated malicious administrator with Enable mode access can execute arbitrary OS commands with elevated syst. Heap-based buffer overflow in Adobe Flash Player before A local attacker could use this issue to cause a denial of service, or possibly escala.
The software contains hard-coded cryptographic key, which it uses for encryption of internal data. Insufficient policy enforcement in Catalog Service in Google Chrome prior to Anaconda Partners Clipper 3. Norton Power Eraser prior to 5. When that response says the data is zero bytes, libcurl would pass on that non-existing data with a pointer and the size zero to the deliver-data function.
To resolve this issue users running 6. Adding method ACLs in remap. The vulnerability makes the product susceptible to cross site scripting attack on its web browser. User inputs can be manip. Inadequate checks in the InputFilter class could allow specifically prepared phar files to pass the upload filter. But ditching this convenient feature could very likely speed up your general PC use significantly. Seagate freeagent goflex desktop 2TB.
In other words, turning off indexing will help your PC's performance only if you seldom search by file content, or if you use a third-party search tool such as Copernic Desktop or Google Desktop in which case you probably have two indexing routines running at the same time, which is an even bigger waste. Seagate freeagent Go for Mac GB.
If you match either of those descriptions, turn off indexing by clicking Start, typing services , and pressing Enter. Find and double-click Windows Search. Offline Files If you work on files stored on a server somewhere, and you can't depend on that server always being available, Vista Business and Ultimate's Offline Files feature makes your life easier by copying the files to your hard drive and keeping them synced.
Seagate freeagent pro GB. Of course, that sort of thing isn't for everybody, which is probably why Microsoft didn't include Offline Files in the Home editions of Vista. But if you have Business or Ultimate and still don't need Offline Files, turn it off by clicking Start, typing services , and pressing Enter. Find and double-click Offline Files. In the 'Startup type' drop-down menu, select Disabled , and then click OK. Seagate freeagent Go special GB. In theory, doing so can help the company locate problems with its OS and heaven knows that would be a good thing.
But more than likely, your report will either go unresolved or just end up in a big ol' pile of other people's reports on the same problem. Either way, you're wasting your system's precious resources on a feature that isn't doing you any good. Samsung G2 portable GB. To disable this unhelpful service, open the Services window: Click Start, type services , and press Enter. Find and double-click Windows Error Reporting Service. UAC: Boon or Bloat?
One of Windows Vista's most controversial new features is User Account Control UAC , which attempts to protect your system from malware by forcing you to authorize certain system-altering actions by clicking through a dialog box from time to time. To some people, this feature is an unwanted annoyance that must be eliminated. Other users appreciate the added security. While I wouldn't go so far as to lump UAC in with the other wasteful features in this article, I can certainly understand why some folks would like to turn it off--or at least minimize its intrusive behavior.
This article is about the electronic device. For experiments in an evacuated pipe, see free-fall. For the transport system, see pneumatic tube. An RCA triode vacuum tube, type In electronics, a vacuum tube, electron tube in North America , or thermionic valve elsewhere, especially in Britain is a device used to amplify, switch, otherwise modify, or create an electrical signal by controlling the movement of electrons in a low-pressure space.
Some special function vacuum tubes are filled with low-pressure gas: these are so-called soft tubes as distinct from the hard vacuum type which have the internal gas pressure reduced as far as possible. Almost all tubes depend on the thermionic emission of electrons. Sony VAIO VGN-FZ18 Battery Vacuum tubes were critical to the development of electronic technology, which drove the expansion and commercialization of radio broadcasting, television, radar, sound reproduction, large telephone networks, analog and digital computers, and industrial process control.
Some of these applications pre-dated electronics, but it was the vacuum tube that made them widespread and practical. Solid-state devices last much longer, are smaller, more efficient, more reliable, and cheaper than equivalent vacuum tube devices. However, tubes are still used in specialized applications: for engineering reasons, as in high-power radio frequency transmitters; or for their aesthetic appeal and distinct sound signature, as in audio amplification.
Cathode ray tubes until very recently were the primary display devices in television sets, video monitors, and oscilloscopes, although they are now being replaced by LCDs and other flat-panel displays. A specialized form of the electron tube, the magnetron, is the source of microwave energy in microwave ovens and some radar systems. The klystron, a powerful but narrow-band radio-frequency amplifier, is commonly deployed by broadcasters as a high-power UHF television transmitter.
Many tubes have glass envelopes, though some types such as power tubes may have ceramic or metal envelopes. The electrodes are attached to leads which pass through the envelope via an airtight seal. On most tubes, the leads are designed to plug into a tube socket for easy replacement.
When hot, the filament releases electrons into the vacuum: a process called thermionic emission. The resulting negatively charged cloud of electrons is called a space charge. These electrons will be drawn to a metal plate inside the envelope, if the plate also called the anode is positively charged relative to the filament or cathode. The result is a flow of electrons from filament to plate. This cannot work in the reverse direction because the plate is not heated and does not emit electrons.
This very simple example described can thus be seen to operate as a diode: a device that conducts current only in one direction. The vacuum tube diode conducts conventional current from plate anode to the filament cathode ; this is the opposite direction to the actual flow of electrons called electron current.
Because of this, vacuum tubes are inherently power-inefficient; enclosing the tube within a heat-retaining envelope of insulation would allow the entire tube to reach the same temperature, resulting in electron emission from the anode that would counter the normal one-way current. Because the tube requires a vacuum to operate, convection cooling of the anode is not generally possible unless the anode forms a part of the vacuum envelope in which case the cooling is by conduction through the anode material and then convection outside the vacuum envelope.
Thus anode cooling occurs in most tubes through black-body radiation and conduction of heat to the outer glass envelope via the anode mounting frame. Cold cathode tubes do not rely on thermionic emission at the cathode and usually have some form of gas discharge as the operating principle; such tubes are used for lighting neon lights and neon glow lamps or as voltage regulators. The vacuum tube is then known as a "triode.
The relationship between this input voltage and the output current is determined by a transconductance function. Control grid current is practically negligible in most circuits. The solid-state device most closely analogous to the vacuum tube is the JFET, although the vacuum tube typically operates at far higher voltage and power levels than the JFET.
The 19th century saw increasing research with evacuated tubes, such as the Geissler and Crookes tubes. These tubes were mostly for specialized scientific applications, or were novelties, with the exception of the light bulb. The groundwork laid by these scientists and inventors, however, as critical to the development of vacuum tube technology. Edison patented what he found, but he did not understand the underlying physics, or the potential value of the discovery.
It wasn't until the early 20th century that this effect was put to use, in applications such as John Ambrose Fleming's diode used as a radio detector, and Lee De Forest's "audion" soon improved by others as the triode in used in the first telephone amplifiers. These developments led to great improvements in telecommunications technology, particularly the first coast-to-coast telephone line in the US, and the birth of broadcast radio. In , as a result of experiments conducted on Edison effect bulbs imported from the USA, he developed a device he called an "oscillation valve" because it passes current in only one direction.
Later known as the Fleming valve, it could be used as a rectifier of alternating current and as a radio wave detector. His invention also included a beam-focusing electromagnet. In Lee De Forest placed a bent wire serving as a screen, later known as the "grid" electrode, between the filament and plate electrode. As the voltage applied to the grid was varied from negative to positive, the number of electrons flowing from the filament to the plate would vary accordingly.
Thus the grid was said to electrostatically "control" the plate current. The resulting three-electrode device was an excellent sensitive amplifier of voltages. De Forest called his invention the "Audion". In , De Forest filed for a three-electrode version of the Audion for use in radio communications. De Forest's device was not strictly a vacuum tube, but clearly depended for its action on ionisation of the relatively high levels of gas remaining after evacuation.
The De Forest company, in its Audion leaflets, warned against operation which might cause the vacuum to become too hard. The Finnish inventor Eric Tigerstedt significantly improved on the original triode design in , while working on his sound-on-film process in Berlin, Germany. The first true vacuum triodes were the Pliotrons developed by Irving Langmuir at the General Electric research laboratory Schenectady, New York in Pliotrons were closely followed by the French 'R' Type which was in widespread use by the allied military by These two types were the first true vacuum tubes.
This is not to be confused with the overdrive that tube amplifiers exhibit at high volume levels known as the tube sound. To remedy the low-volume distortion problem, engineers plotted curves of the applied grid voltage and resulting plate currents, and discovered that there was a range of relatively linear operation.
In order to use this range, a negative voltage had to be applied to the grid to place the tube in the "middle" of the linear area with no signal applied. This was called the idle condition, and the plate current at this point the "idle current". Today this current would be called the quiescent or standing current. The controlling voltage was superimposed onto this fixed voltage, resulting in linear swings of plate current for both positive and negative swings of the input voltage.
Tetrodes and pentodes A two-tube homemade radio from The tubes are the two columns with the dark tops. The flying leads connect to the low-voltage filament and high-voltage anode supplies. When triodes were first used in radio transmitters and receivers, it was found that they had a tendency to oscillate due to parasitic anode-to-grid capacitance. Many circuits were developed to reduce this problem e. It was discovered that the addition of a second grid, located between the control grid and the plate and called a screen grid could solve these problems.
A positive voltage slightly lower than the plate voltage was applied to it, and the screen grid was bypassed for high frequencies to ground with a capacitor. An additional side effect of this second grid is that the Miller capacitance is also reduced, which improves gain at high frequency. This two-grid tube is called a tetrode, meaning four active electrodes, and was common by The braided copper leads provide heater current for the cathode.
The tube also has a heat sink. Dubendorf Museum of Military Aviation. In any tube, electrons strike the anode hard enough to knock out secondary electrons. In a triode these less energetic electrons cannot reach the grid or cathode, and are re-captured by the anode.
But in a tetrode, they can be captured by the second grid, reducing the plate current and the amplification of the circuit. Since secondary electrons can outnumber the primary electrons, in the worst case, particularly when the plate voltage dips below the screen voltage, the plate current can actually go down with increasing plate voltage.
This is negative-resistance behavior. Another consequence of this effect is that under severe overload, the current collected by the screen grid can cause it to overheat and melt, destroying the tube. This third grid was biased at either ground or cathode voltage and its negative voltage relative to the anode electrostatically suppressed the secondary electrons by repelling them back toward the anode.
This three-grid tube is called a pentode, meaning five electrodes. The pentode was invented in by Bernard D. Improvements in construction and performance The very earliest vacuum tubes strongly resembled incandescent light bulbs and were made by lamp manufacturers, who had the equipment for manufacture of glass envelopes and the powerful vacuum pumps required to evacuate the enclosures. After World War I, specialized manufacturers using more economical construction methods were set up to fill the growing demand for broadcast receivers.
This in turn improved tube gain, since the gain of a triode is inversely proportional to the spacing between grid and cathode. Development of the indirectly-heated cathode, with the filament inside a cylinder of oxide-coated nickel, further reduced distortion of the tube elements and also allowed the cathode heaters to be run from an AC supply.
A considerable amount of heat is produced when tubes operate. The requirements for heat removal significantly change the appearance of high-power vacuum tubes. The first one of these is the filament or heater. Some types contain a directly heated cathode. This is a filament similar to an incandescent electric lamp and some types glow brightly like a lamp, but most glow dimly. The "dull emitter" types also possess a tungsten filament but it is coated in a mixture of calcium, strontium and barium oxides, which emit electrons easily at much lower temperatures due to a monolayer of mixed alkali earth metals coating the tungsten when the cathode is heated to about degrees Celsius.
Sony VAIO VGN-FZ70B Battery The second form of cathode is the indirectly heated form which usually consists of a nickel tube, coated on the outside with the same strontium, calcium, barium oxide mix used in the "dull emitter" directly heated types, and fitted with a tungsten filament inside the tube to heat it.
This tungsten filament is usually uncoiled and coated in a layer of alumina, aluminium oxide , to insulate it from the nickel tube of the actual cathode. This form of construction allows for a much greater electron emitting area and, because the heater is insulated from the cathode, the cathode can be positioned in a circuit at up to volts more positive than the heater or 50 volts more negative than the heater for most common types.
It also allows all the heaters to be simply wired in series or parallel rather than some requiring special isolated power supplies such as specially insulated windings on power transformers or separate batteries. Some signal amplifiers, particularly high-frequency amplifiers such as the 6BA6, consume some 5. In tubes used in power amplifier or transmitting circuits, this source of heat will exceed the power dissipated in the cathode heater. The plates or anodes of 6L6 devices used in guitar amplifiers can sometimes be seen to reach red heat if the bias is set too high, they should not emit any visible radiation when driven at maximum ratings.
No tubes in domestic, music, or studio equipment should operate with glowing anodes. Some is conducted away through the connecting wires going to the base but none is convected in most types of tube because of the vacuum and the absence of any gas inside the bulb to convect. It is the way tubes get rid of heat which most affects their overall appearance, next to the type of unit triode, pentode, etc.
For devices required to radiate more than mW or so, usually indirectly heated cathode types, the anode or plate is often treated to make its surface less shiny, see black body radiator , and to make it darker, either gray or black.
This helps it radiate the generated heat and maintain the anode or plate at a temperature significantly lower than the cathode, a requirement for proper operation. Limits to grid dissipation are listed for such devices, to prevent distortion and failure of the grids. Tubes used as power amplifier stages for radio transmitters may have additional heat exchangers, cooling fans, radiator fins, or other measures to improve heat transfer at the anode.
Broadcast transmitters may use water-cooling or evaporative cooling for tube anodes. The water cooling system must withstand the high voltages present on the anode. Gas filled tubes, such as thyratrons, although they possess a greater plate dissipation than a "1 volt battery type", still often possess a shiny metal anode finish as the gas filling conducts and convects the heat to the bulb wall.
Types and 2D21 are typical examples. Some small signal types, such as sharp and remote cut-off R. This shield is sometimes a solid metal sheet, treated to make it dull and gray like an anode or plate, and sometimes it is fabricated from expanded metal mesh, acting as a Faraday cage but allowing sufficient heat from the anode beneath to escape.
Indicators such as some "magic eye" tubes and the type fluorescent-anode type have glowing electrodes. Frequency conversion can be accomplished by various methods in superheterodyne receivers. Tubes with 5 grids, called pentagrid converters, were generally used, although alternatives such as using a combination of a triode with a hexode were also used. Even octodes have been used for frequency conversion. The additional grids are either control grids, with different signals applied to each one, or screen grids.
In many designs a special grid acted as a second 'leaky' plate to provide a built-in oscillator, which then coupled this signal with the incoming radio signal. These signals create a single, combined effect equivalent to a crude analog multiplier on the plate current and thus the signal output of the tube circuit. The useful component of the output was the difference frequency between that of the incoming signal and that of the oscillator. Octodes were rare in the US, the 7A8 was one example, but much more common in Europe particularly in battery operated radios where the lower power consumption was an advantage.
Toward the end of the tube era, precision control and screen grids, called frame grids, offered enhanced performance. Instead of the typically elliptical fine-gauge wire supported by two larger wires, a frame grid was a metal stamping with rectangular openings that surrounded the cathode. The grid wires were in a plane defined by the stamping, and the control grid was placed much closer to the cathode surface than traditional construction would permit.
The only constraint was where patents, and other licencing considerations required the use of multiple tubes. See British Valve Association. The same set of tubes often included the 53 Dual Triode Audio Output. Another early type of multi-section tube, the 6SN7, is a "dual triode" which, for most purposes, can perform the functions of two triode tubes, while taking up half as much space and costing less. The invention of the 9-pin miniature tube base, besides allowing the 12AX7 family, also allowed many other multi section tubes, such as the 6GH8 triode pentode.
Along with a host of similar tubes, the 6GH8 was quite popular in television receivers. Some color TV sets used exotic types like the 6JH8 which had two plates and beam deflection electrodes it was known as the 'sheet beam' tube. Vacuum tubes used like this were designed for demodulation of synchronous signals, an example of which is color demodulation for television receivers.
The desire to include many functions in one envelope resulted in the General Electric Compactron. A typical unit, the 6AG11 Compactron tube contained two triodes and two diodes, but many in the series had triple triodes. An early example of multiple devices in one envelope was the Loewe 3NF. This s device had 3 triodes in a single glass envelope together with all the fixed capacitors and resistors required to make a complete radio receiver.
As the Loewe set had only one tube socket, it was able to substantially undercut the competition since, in Germany, state tax was levied by the number of sockets. However, reliability was compromised, and production costs for the tube were much greater. In a sense, these were akin to integrated circuits. This Emerson set also had a single tube socket, but because it used a four-pin base, the additional element connections were made on a "mezzanine" platform at the top of the tube base.
Vacuum tubes in an Australian radio of the late s The beam power tube is usually a tetrode with the addition of beam-forming electrodes, which take the place of the suppressor grid. These angled plates focus the electron stream onto certain spots on the anode which can withstand the heat generated by the impact of massive numbers of electrons, while also providing pentode behavior.
The positioning of the elements in a beam power tube uses a design called "critical-distance geometry", which minimizes the "tetrode kink", plate-grid capacitance, screen-grid current, and secondary emission effects from the anode, thus increasing power conversion efficiency. The control grid and screen grid are also wound with the same pitch, or number of wires per inch. This design helps to overcome some of the practical barriers to designing high-power, high-efficiency power tubes.
Variations of the 6L6 design are still widely used in guitar amplifiers, making it one of the longest lived electronic device families in history. Similar design strategies are used in the construction of large ceramic power tetrodes used in radio transmitters. For instance, voltage regulator tubes contain various inert gases such as argon, helium or neon, and take advantage of the fact that these gases will ionize at predictable voltages.
The thyratron is a special-purpose tube filled with low-pressure gas or mercury, some of which vaporizes. Like other tubes, it contains a hot cathode and an anode, but also a control electrode, which behaves somewhat like the grid of a triode. When the control electrode starts conduction, the gas ionizes, and the control electrode no longer can stop the current; the tube "latches" into conduction.
Removing plate anode voltage lets the gas de-ionize, restoring its non-conductive state. Some thyratrons can carry large currents for their physical size. One example is the miniature type 2D21, often seen in s jukeboxes as control switches for relays.
It can switch thousands of amperes in its largest versions. Thyratrons containing hydrogen have a very consistent time delay between their turn-on pulse and full conduction, and have long been used in radar transmitters. Thyratrons behave much like silicon-controlled rectifiers, or to be more chronologically precise, silicon controlled rectifiers mimic some of the behaviours of Thyratrons. The first version of the 6L6 used a metal envelope sealed with glass beads, while a glass disk fused to the metal was used in later versions.
Metal and ceramic are used almost exclusively for power tubes above 2 kW dissipation. The nuvistor is a tiny tube made only of metal and ceramic. In some power tubes, the metal envelope is also the anode. The 4CXA is an external anode tube of this sort. Air is blown through an array of fins attached to the anode, thus cooling it.
Power tubes using this cooling scheme are available up to kW dissipation. Above that level, water or water-vapor cooling are used. By comparison, the largest power transistor can only dissipate about 1 kilowatt. Another very high power tube is the Eimac , a 1.
An extremely specialized tube is the Krytron, which is used for extremely precise, rapid high-voltage switching. Due to their intended purpose, the initiation of the precise sequence of detonations used to set off a nuclear weapon, they are heavily controlled at an international level. Medical imaging equipment, such as radiographic and nuclear imaging, use special vacuum tubes. Radiographic, fluoroscopic, and CT X-ray imaging equipment use a specially designed vacuum tube diode, which has a rotating anode to dissipate the large amounts of heat developed during operation, and a focused cathode.
They are housed in an aluminum housing which is filled with a dielectric oil. Nuclear imaging equipment uses photomultiplier tube arrays to detect radiation. It was invented in This forces the sealing tip to the top of the envelope. Making tubes smaller reduced the voltage that they could work at, and also the power of the filament, so the older style continued to be used for high power rectifiers, valve amplifier output stages and certain transmitting tubes.
Miniature tubes with a size roughly that of half a cigarette were used in hearing-aid amplifiers. Powering the tube Batteries Batteries provided the voltages required by tubes in early radio sets. As many as three different voltages were required, using three different batteries. The "A" batteries or LT low-tension battery provided the filament voltage. Tube heaters were designed for single, double or triple-cell lead-acid batteries, giving nominal heater voltages of 2 V, 4 V or 6 V.
In portable radios, dry batteries were sometimes used with 1. Reducing filament consumption improved the life span of batteries. By , receiving tubes using 50 mA down to as little as 10 mA for the heaters had been developed, but they were swept aside by development of the transistor. These were generally of dry cell construction, containing many small 1.
They typically came in ratings of Some sets used a grid bias battery or "C" batteries, although many circuits used grid leak resistors, voltage dividers or cathode bias to provide proper tube bias. These batteries had very low drain.
Batteries for a vacuum tube circuit. The C battery is highlighted. For the three-prong to two-prong mains plug adapter, see Cheater plug. Replacement of batteries was a major cost of operation for early radio receiver users. The development of the battery eliminator, and, in , batteryless receivers operated by household power, reduced operating costs and contributed to the growing popularity of radio.
A power supply using a transformer with several windings, one or more rectifiers which may themselves be vacuum tubes , and large filter capacitors provided the required direct current voltages from the alternating current source. Sony VAIO VGN-FZ31J Battery As a cost reduction measure, especially in high-volume consumer receivers, all the tube heaters could be connected in series across the AC supply, and the plate voltage derived from a half-wave rectifier directly connected to the AC input, eliminating the need for a heavy power transformer.
As an additional feature, these radios could be operated on AC or DC mains. While this arrangement limited the plate voltage and so, indirectly, the output power that could be obtained, the resulting supply was adequate for many purposes. A filament tap on the rectifier tube provided the 6 volt, low current supply needed for a dial light. The so-called series string approach did have one safety defect: the chassis of the receiver was connected to one side of the power supply, presenting a shock hazard.
Engineers reduced this hazard by enclosing the chassis in a plastic case, making the back out of particle board, and riveting the power cord chassis plug to the back so that consumers would not be able to power the radio while the chassis was accessible. Technicians and tinkerers routinely bypassed this by using a separate cord, known colloquially as a "cheater cord" or "widowmaker.
It became common to use the filament to heat a separate electrode called the cathode, and to use this cathode as the source of electron flow in the tube rather than the filament itself. This minimized the introduction of hum when the filament was energized with alternating current.
In such tubes, the filament is called a heater to distinguish it as an inactive element. Development of vacuum tubes that could use alternating current for the heater supply allowed elimination of one rectifier element. Sony VAIO VGN-FZ38 Battery Reliability Tube tester manufactured in One reliability problem of tubes with oxide cathodes is the possibility that the cathode may slowly become "poisoned" by gas molecules from other elements in the tube, which reduce its ability to emit electrons.
Trapped gases or slow gas leaks can also damage the cathode or cause plate-current run away due to ionization of free gas molecules. Vacuum hardness and proper selection of construction materials are the major influences on tube lifetime. Depending on the material, temperature and construction, the surface material of the cathode may also diffuse onto other elements.
The resistive heaters that heat the cathodes may break in a manner similar to incandescent lamp filaments, but rarely do, since they operate at much lower temperatures than lamps. Sony VAIO VGN-FZ38 Battery The heater's failure mode is typically a stress-related fracture of the tungsten wire or at a weld point and generally occurs after accruing many thermal power on-off cycles.
Tungsten wire has a very low resistance when at room temperature. A negative temperature coefficient device, such as a thermistor, may be incorporated in the equipment's heater supply or a ramp-up circuit may be employed to allow the heater or filaments to reach operating temperature more gradually than if powered-up in a step-function.
Low-cost radios had tubes with heaters connected in series, with a total voltage equal to that of the line mains. Earlier designs had quite-different thermal time constants. The audio output stage, for instance, had a larger cathode, and warmed up more slowly than lower-powered tubes.
The result was that heaters that warmed up faster also temporarily had higher resistance, because of their positive temperature coefficient. This disproportionate resistance caused them to temporarily operate with heater voltages well above their ratings, and shortened their life. Usually oxygen in the air reacts chemically with the hot filament or cathode, quickly ruining it.
Designers developed tube designs that sealed reliably. This was why most tubes were constructed of glass. Metal alloys such as Cunife and Fernico and glasses had been developed for light bulbs that expanded and contracted in similar amounts, as temperature changed. These made it easy to construct an insulating envelope of glass, while passing connection wires through the glass to the electrodes. When a vacuum tube is overloaded or operated past its design dissipation, its anode plate may glow red.
In consumer equipment, a glowing plate is universally a sign of an overloaded tube. However, some large transmitting tubes are designed to operate with their anodes at red, orange, or in rare cases, white heat. This can indicate a "gassy" tube; however, this effect is commonly the result of electron bombardment of impurities in the glass envelope.
The vacuum inside the envelope must be as perfect, or "hard", as possible. Any gas atoms remaining might be ionized at operating voltages, and will conduct electricity between the elements in an uncontrolled manner. This can lead to erratic operation or even catastrophic destruction of the tube and associated circuitry. Unabsorbed free air sometimes ionizes and becomes visible as a pink-purple glow discharge between the tube elements.
Sony VAIO VGN-FW11M Battery To prevent any remaining gases from remaining in a free state in the tube, modern tubes are constructed with "getters", which are usually small, circular troughs filled with metals that oxidize quickly, with barium being the most common. While the tube envelope is being evacuated, the internal parts except the getter are heated by RF induction heating to extract any remaining gases from the metal. The tube is then sealed and the getter is heated to a high temperature, again by radio frequency induction heating.
The getter continues to absorb any gas molecules that leak into the tube during its working life. If a tube develops a crack in the envelope, this deposit turns a white color when it reacts with atmospheric oxygen. Large transmitting and specialized tubes often use more exotic getter materials, such as zirconium. Early gettered tubes used phosphorus based getters and these tubes are easily identifiable, as the phosphorus leaves a characteristic orange or rainbow deposit on the glass.
The use of phosphorus was short-lived and was quickly replaced by the superior barium getters. Unlike the barium getters, the phosphorus did not absorb any further gases once it had fired. An extremely thin molecular layer of thorium atoms forms on the outside of the wire's carbonized layer and, when heated, serve as an efficient source of electrons.
The thorium slowly evaporates from the wire surface, while new thorium atoms diffuse to the surface to replace them. Such thoriated tungsten cathodes usually deliver lifetimes in the tens of thousands of hours. The end-of-life scenario for a thoriated-tungsten filament is when the carbonized layer has mostly been converted back into another form of tungsten carbide and emission begins to drop off rapidly; a complete loss of Thorium has never been found to be a factor in the end-of-life in a tube with this type of emitter.
While it was commonly believed that at rf power levels above approx. FM broadcast transmitters with solid state power amplifiers up to approx. An electric heater is inserted into the cathode sleeve, and insulated from it electrically by a coating of aluminium oxide. This complex construction causes barium and strontium atoms to diffuse to the surface of the cathode when heated to about degrees Celsius, thus emitting electrons.
A crack in the glass envelope will allow air into the tube and destroy it. Cracks may result from stress in the glass, bent pins or impacts; tube sockets must allow for thermal expansion, to prevent stress in the glass at the pins. Stress may accumulate if a metal shield or other object presses on the tube envelope and causes differential heating of the glass.
Glass may also be damaged by high-voltage arcing. Tube heaters don't normally fail by evaporation like lamp filaments, since they operate at much lower temperature. The surge of inrush current when the heater is first energized causes stress in the heater, and can be avoided by slowly warming the heaters, gradually increasing current.
Some tubes intended for series string operation of the heaters across the supply will have a definite controlled warm-up time to avoid excess voltage on some heaters as others warm up. Directly-heated filament-type cathodes as used in battery-operated tubes or some rectifiers may fail if the filament sags, causing internal arcing. Excess heater-to-cathode voltage in indirectly heated cathodes can break down the insulation between elements and destroy the heater. An arc can be caused by applying plate potential before the cathode has come up to operating temperature, or by drawing excess current through a rectifier which damages the emission coating.
Arcs can also be initiated by any loose material inside the tube, or by excess screen voltage. An arc inside the tube allows gas to evolve from the tube materials, and may deposit conductive material on internal insulating spacers. Overheating of internal parts, such as control grids or mica spacer insulators, can result in trapped gas escaping into the tube; this can reduce performance.
A getter is used to absorb gases evolved during tube operation, but has only a limited ability to combine with gas. Control of the envelope temperature prevents some types of gassing. A tube with very bad internal gas may have a visible blue glow when plate voltage is applied. Another effect of overheating is the slow deposit of metallic vapors on internal spacers, resulting in inter-element leakage. Tubes on standby for long periods, with heater voltage applied, may develop high cathode interface resistance and display poor emission characteristics.
This effect occurred especially in pulse and digital circuits, where tubes had no plate current flowing for extended times. Sometimes emission can be restored for a time by raising heater voltage either for a short time or a permanent increase of a few percent. Cathode depletion was uncommon in signal tubes but was a frequent cause of failures of monochrome television cathode-ray tubes.
Microphonics refers to internal vibration of tube elements, which modulates the signal from the tube in an undesirable way; sound or vibration pick-up may affect the signals, or even cause uncontrolled howling if a feedback path develops between a microphonic tube and, for example, a loudspeaker.
Leakage current between AC heaters and the cathode may couple into the circuit, or electrons emitted directly from the ends of the heater may also inject hum into the signal. Leakage current due to internal contamination may also inject noise. Computer vacuum tubes See also: List of vacuum tube computers Colossus Colossus and its successor Colossus Mk2 was built by the British during World War II to substantially speed up the task of breaking the German high level Lorenz encryption.
Based on vacuum tubes, Colossus replaced an earlier machine based on relay and switch logic the Heath Robinson. Colossus was able to break in a matter of hours messages that had previously taken several weeks. Colossus Mk2 used a total of around vacuum tubes. Colossus was the first ever use of vacuum tubes on such a large scale for a single machine. The largest project previously had used just tubes and had proven to be extremely unreliable.
The main design problem at Colossus's inception was how to make vacuum tube based equipment reliable when the tubes were used in large numbers. Tommy Flowers, had a theory that most of the unreliability was caused during power down and mainly power up. Once Colossus was built and installed, it was switched on and left switched on running from dual redundant diesel generators the wartime mains supply being considered too unreliable.
The only time it was switched off was for conversion to the Colossus Mk2 and the addition of another or so tubes. Another 9 Colossus Mk2s were built, and all 10 machines ran with a surprising degree of reliability. The 10 Colossi consumed 15 kilowatts of power each, 24 hours a day, days a year—nearly all of it for the tube heaters.
The problem of short lifetime was traced to evaporation of silicon, used in the tungsten alloy to make the heater wire easier to draw. Elimination of the silicon from the heater wire alloy and paying extra for more frequent replacement of the wire drawing dies allowed production of tubes that were reliable enough for the Whirlwind project.
The tubes developed for Whirlwind later found their way into the giant SAGE air-defense computer system. High-purity nickel tubing and cathode coatings free of materials that can poison emission such as silicates and aluminium also contribute to long cathode life. The first such "computer tube" was Sylvania's 7AK7 of By the late s it was routine for special-quality small-signal tubes to last for hundreds of thousands of hours, if operated conservatively.
This reliability made mid-cable amplifiers in submarine cables possible. The tube is a special quality type based on the EF72, 35 mm long and 10 mm in diameter excluding leads. Near the end of World War II, to make radios more rugged, some aircraft and army radios began to integrate the tube envelopes into the radio's cast aluminium or zinc chassis.
The radio became just a printed circuit with non-tube components, soldered to the chassis that contained all the tubes. During WWII in , rugged metal vacuum tubes were mounted in anti-aircraft shells. These proximity fuzes made anti-aircraft shells 6 times more effective. In the fall of , artillery shells with proximity fuses were used. The tiny tubes were later known as "subminiature" types.
They were widely used in s military and aviation electronics. Tubes were heavily used in the early generations of electronic devices, such as radios, televisions, and early computers such as the Colossus which used tubes, the ENIAC which used nearly 18, tubes, and the IBM series. Cathode ray tubes are still used as display devices in television sets, video monitors, and oscilloscopes, although they are being replaced by LCDs and other flat-panel displays.
This property kept them in use for certain military applications long after transistors had replaced them elsewhere. Vacuum tubes are still used for very high-powered applications such as industrial radio-frequency heating, generating large amounts of RF energy for particle accelerators, and power amplification for broadcasting. In microwave ovens, cost-engineered magnetrons efficiently generate microwave power on the order of hundreds of watts.
Many audiophiles, professional audio engineers, and musicians prefer the tube sound of audio equipment based on vacuum tubes over electronics based on transistors. There are companies which still make specialized audio hardware featuring tube technology. A common usage is in the high-end microphone preamplifiers preferred by professional music recording studios, and in electric guitar amplification.
The sound produced by a tube based amplifier with the tubes overloaded overdriven has defined the texture of some genres of music such as classic rock and blues. Guitarists often prefer tube amplifiers for the warmth of their tone and the natural compression effect they can apply to an input signal.
Cathode-ray tubes CRTs are a highly-evolved type of vacuum tube, described elsewhere. AOpen claims that the vacuum tube brings superior sound. Like any electronic device, vacuum tubes produce heat while operating. This waste heat is one of the principal factors that affect tube life . The majority of this waste heat originates in the anode though some grids may also require cooling to remove excess heat.
For example, the cooling of the screen grid in an EL34 is facilitated by the addition of two small radiators or "wings," located near the top of the tube. The heater filament also contributes to the total waste heat. A tube's data sheet will normally identify the maximum amount of heat each element may dissipate. Kingston DDR3 mhz 2gb The method of anode cooling is dependent on the construction of the tube itself.
For tubes with internal anodes such as the 12AX7 or EL34, the cooling occurs by radiating the heat by black body radiation from the anode to the glass envelope . Natural air circulation, convection, then removes the heat from the envelope. Tube shields that aided heat dispersal could be retrofitted on certain select types of tubes.
These shields act by improving heat conduction from the surface of the tube to the shield itself by means of tens of copper tongues in contact with the glass tube, and have an opaque, black outside finish for improved heat radiation. The ability to remove heat may be further increased by implementing forced air cooling, adding fins to the anode, and operating the anode at red hot temperatures.
All of these measures are implemented in the A transmitting tube. Kingston DDR3 mhz 4gb The amount of heat that may be removed from a tube with an internal anode is limited . Tubes with external anodes may be cooled using forced air, water, vapor, and multiphase. The 3CX10,A7 is an example of a tube with an external anode cooled by forced air. The water, vapor, and multiphase cooling techniques all depend on the high specific heat and latent heat of water.
The is an example of a water cooled tube and is among the largest commercial tube available today. Kingston DDR3 mhz 2gb In a water cooled tube, the anode voltage appears directly on the cooling water surface, thus requiring the water to be an electrical insulator. Otherwise the high voltage can be conducted through the cooling water to the radiator system; hence the need for deionized water. Such systems usually have a built-in water-conductance monitor which will shut down the high-tension supply often tens of kilovolts if the conductance becomes too high.
Most such tubes were rendered obsolete by semiconductors; some techniques for integrating multiple devices in a single module, sharing the same glass envelope have been discussed above, such as the Loewe 3NF. Vacuum-tube electronic devices still in common use include the magnetron, klystron, photomultiplier, x-ray tube, traveling-wave tube and cathode ray tube. The magnetron is the type of tube used in all microwave ovens. In spite of the advancing state of the art in power semiconductor technology, the vacuum tube still has reliability and cost advantages for high-frequency RF power generation.
Photomultipliers are still the most sensitive detectors of light. Many televisions, oscilloscopes and computer monitors still use cathode ray tubes, though flat panel displays are becoming more popular as prices drop. These tubes were used as a visual indication of received signal strength, and an aid to properly tuning in a station.
That old truism goes double for computers. But some PC geeks are so fanatical about performance, so doggedly determined to push their hardware to extremes, that they'll go to ridiculous lengths to wring a few more clock cycles out of their components or add a little more cool factor to their rig. Seagate expansion GB This article is dedicated to all those insane, irrational enthusiasts who defy all reason and common sense in the pursuit of PC glory. We've tried and tested five risky upgrades that no sane user should ever try.
Don't get us wrong--these upgrades deliver genuine benefits. But they aren't for the faint of heart, as each is either time-consuming, expensive, or dangerous to your hardware. If you like to walk on the wild side, though, grab your screwdriver and follow along. Want better screen resolution, or maybe a glossy display instead of a matte one? Subbing in a new LCD panel for your old one is a bit extreme, but doable. This upgrade is one of the trickiest and most time-consuming laptop surgeries you can perform, with little guarantee that the new screen will work as it should.
Still, if you do your homework in advance and select the right hardware for your machine, the payoff can be spectacular. Seagate expansion 1TB Step 2: Remove the keyboard, unplug the display's antenna and data cables from the motherboard, and undo the hinge screws to release the display assembly from the machine.
According to replacement-LCD supplier ScreenTek, upgrading a screen can, unfortunately, be a matter of trial and error. Whether a higher-resolution screen will work on your notebook depends on many factors, including the laptop's video card, cable, and firmware. And of course, the new display must fit in the space available. Seagate expansion 1. Step 3: Remove the bezel from the display assembly to free the LCD panel from its enclosure.
To replace the LCD on our Dell E, we first had to remove the laptop's hinge cover and keyboard, by taking out screws from the bottom and rear of the machine; then we had to unplug the antenna and video cables from the motherboard. Those steps allowed us to remove the LCD assembly from the laptop's main body.
Taking off the small rubber bumpers on the front of the screen revealed screws beneath. We removed the screws and then pried the bezel away from the screen, gaining access to the bare LCD beneath. We had to work slowly: It's easy to snap the plastic on the bezel during this part of the disassembly. Seagate expansion 2TB Step 4: You may need to take the data cable from your old display and attach it to your new one to ensure compatibility with your motherboard.
Brackets on each side of the LCD hold it in place. After removing the screws and unplugging the cables, we finally took out the bare LCD and replaced it with the new one. Then we simply reversed the disassembly process to put everything back together properly.
Seagate freeagent desktop GB. Prior to reassembly, plug the cables in and boot the machine up to ensure that it's working correctly. If you don't get a picture, check that the cables are properly seated, and try again. If it still doesn't work, your notebook simply may not support that display resolution Seagate freeagent desktop1TB. If this risky upgrade is too nuts for your blood, check out five way easier laptop upgrades. Or, for more-concrete performance benefits, upgrade your laptop's CPU orgraphics card.
With a bit of care and common sense, anyone can squeeze a little extra speed out of their processor. But if you want to push your hardware to illogical extremes, you'll have to get your hands dirty. And that means lapping your CPU. Seagate freeagent desktop1. Lapping is a fancy word that machinists use for sanding. In this case, you'll be sanding the metal plate that sits on top of the CPU. This plate, known as an integrated heatspreader, serves not only to keep you from crushing your CPU core when installing a heat-sink-and-fan combination but also to transfer heat away from the processor.
Sanding it to a flat finish ensures that it makes optimal contact with the heat sink. Seagate freeagent desktop2TB But since the heatspreader's surface already comes machine-lapped from the factory, why repeat the process at home and risk destroying a perfectly good CPU? A reckless disregard for safe computing is one answer. But if you were to look at your processor through a microscope, you might be surprised at what you'd find.
Though the surface may appear smooth and flat to the naked eye, your CPU's heatspreader actually contains many microscopic nicks, depressions, and other flaws that prevent it from making the best possible contact with your CPU cooler. Seagate freeagent Go GB Thermal pads and pastes help fill in those imperfections, but only by lapping your processor to an ultrasmooth finish can you be assured of whisking away the most heat. Of course, you'll also be whisking away your warranty, but unless you're one of those sane people who run their processors at stock speed, you've already voided it anyway.
Seagate freeagent Go GB What You'll Need Sandpaper , , , , , and grit in full- or half-sheet form Isopropyl rubbing alcohol 90 percent concentration or higher or ArctiClean Masking tape Cotton swabs or unscented toilet paper Can of compressed air Pane of glass or some other smooth, flat surface larger than the sheets of sandpaper Seagate freeagent Go GB A pane of glass, a few sheets of sandpaper, some rubbing alcohol, masking tape, cotton swabs, and canned air are all you need to grind--and potentially destroy--your CPU.
You can find the coarser varieties of sandpaper at any local hardware store or supercenter; but for grit and finer sheets, you'll likely have to visit an auto-parts dealer. Look for variety packs to save on costs, and don't fret if you can't find full sheets--you need just about a foot of vertical space to work with.
Seagate freeagent Go GB. Set Up Your Workspace Lay down the pane of glass so that you have a completely flat, supersmooth surface to work on. Seagate freeagent Go GB Grab a full sheet of grit sandpaper and cut it in half, and then secure one of the pieces vertically to your work surface by placing masking tape around all four sides. Now might also be a good time to call your mother if you haven't talked with her for months. The resulting good karma might later make the difference between a cooler-running processor and one that refuses to boot.
Because you'll be removing layers of nickel and copper from the heatspreader, you want to protect the CPU's circuitry from getting all gunked up. We're not just being OCD here; mixing metal flakes with internal circuits is not only a sure way to fry your processor, but it can also destroy your motherboard. To keep that from happening, take four strips of masking tape and butt each one up against the raised part of the heatspreader, folding the excess underneath the CPU.
This will prevent any flakes from sneaking under the heatspreader where the CPU core sits exposed or dirtying up the contact points on the bottom as sand and metal start to fly. Seagate freeagent Go GB black way its top few metal layers.
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This almost just requires a new setup program which Timothy Gack is developing at the moment. Together with the next release, the home page is going to be restructured. Albert Alcaine is currently working on the design. Linux is making its way to more and more systems.
And Tux is already doing his new job inside Windows very well. You can watch him when you download and install the latest 2. So, the next year will certainly bring the release of 2. Stay tuned for further news! You may as well add your own modifications to the source code, if you re-distribute the result once again covered by the GPL.
Additional details can be found in the GPL. The ready-to-use driver software as well as the source code are available for download, compressed in ZIP-files. They can be opened and unpacked with commonly available decompression-tools. If you experience any problems, please test with the previous version. I might have added an «unwanted feature». The contained setup wizard will guide you through the installation steps. Well, volunteers to come up with translations are welcomed! I am more than happy to assist anyone in finding all the relevant areas in the source code.
And I can certainly compile the translated version. Since release 0. See winpcap-irda. The latest version of the Linux tool irdadump allows offline capturing also on this platform. Look out for irda-utils 0. To enable realtime capturing on Linux, a recent libpcap version is required 0.
Es darf frei kopiert und verwendet werden. Ebenso sind eigene Modifikationen der Quelltexte erlaubt, sofern das Ergebnis wieder unter der GPL weitergegeben wird. Sollten Probleme auftreten, bitte auch die vorige Version ausprobieren. Vielleicht habe ich etwas «verschlimmbessert». Der enthaltene Installationsassistent leitet dann durch die erforderlichen Schritte.
Seit Release 0. Weitere Informationen sind in winpcap-irda. Die irda-utils Version 0. Otherwise you may fail to Unzip and install the driver due to «Incomplete Download». NOTE: b. Please temporarily disable Antivirus Real Time Protection or open a window for downloading to prevent from Over-Protection , causing "Incomplete Download". Please check downloaded file size to see if it has the same size as original on the web site.
Otherwise you may fail to Unzip and install the driver due to "Incomplete Download". Please contact tech-support actisys. In such a case there will be no Windows 10 driver, may need to buy new IR adapter with new IC inside. This can be identified by your IR adapter serial number.
After running this software and complete un-installation is done, please reboot your PC. Then install the new driver. For Mac OS X Linux Kernel 2. Actually they share the same driver. Please download other drivers from above IRx24UN just in case needed. They actually share the same. However, IrComm2K does N ot support 64bit.
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