Testing Diode-The Accurate Way on How to Test Semiconductor Diode Using Multimeter

Written by Jestine Yong

Testing diodes is different from testing a resistor because you need a skill to do it. If you do not know or wrongly test a diode you will be unable to repairrepparttar equipment. A bad diode you think it is good. This will definitely waste your precious time.

A rectifier diode can fail in one ofrepparttar 142879 four ways. It can become: -Open -Shorted -Leaky -Breakdown when in full operating voltage An analog multimeter or digital multimeter can be used to check for allrepparttar 142880 first three conditions exceptrepparttar 142881 last one whererepparttar 142882 diode breakdown in full operating voltage. From my of experienced inrepparttar 142883 electronic repairing line, i found that checking diode using analog multimeter is more accurate than using a digital multimeter. I could explain to you why i preferred analog meter. I do not know about you because i really came across quite a number of diodes where it checked ok using digital multimeter but failed when test with analog meter.

The first step on how to test a diode is to remove one ofrepparttar 142884 diode lead. You can't always be certain if a diode is good or bad if you perform in-circuit test, because of back circuits through other components. To be absolutely sure, you will need to lift, or disconnect, one diode lead fromrepparttar 142885 circuit to avoid back circuits. Unless you are very sure aboutrepparttar 142886 board you are checking. Sometimes i do found bad diodes when checking it on board. Your experienced will tell you when to check a diode on-board or off-board. If you are new to electronic repair, i highly recommend that you check a diode with a lead removed fromrepparttar 142887 board.

I will set my analog meter to x1 ohms to check for current diode leakage reverse and forward testing. Connectingrepparttar 142888 black probe of your meter torepparttar 142889 cathode and red probe torepparttar 142890 anode,repparttar 142891 diode is reverse biased and should look like an open reading. Connectingrepparttar 142892 red probe of your meter torepparttar 142893 cathode and black probe torepparttar 142894 anode,repparttar 142895 diode is forward biased andrepparttar 142896 meter should read some value of resistance. If you have two readings then most probablyrepparttar 142897 diode is shorted or leaky and you should replace it. If you don't get any reading either forward or reverse bias,repparttar 142898 diode is considered open.

Spy Vs Spy Vs Spy

Written by Luigi Di Serio

A quick overview onrepparttar evolution of keyloggers and spy software and their “antispy” counterpart --------------

They started off as tiny, little programs that computer geeks and programmers used to log and monitor keystrokes for personal use, but eventually someone realized that these applications known as “keyloggers” would be one ofrepparttar 142878 easiest applications to market onrepparttar 142879 web. The FBI already used a program known as “magic lantern”, butrepparttar 142880 public did no become aware of such programs until later.

Until Mikkotech (http://www.mikkotech.com) made onerepparttar 142881 first keystroke recorders available torepparttar 142882 general public called “KeyKey Monitor,” which was used primarily as a security and back-up application, available on a handful of shareware sites.

Enter a scheming marketer. They cut a deal with Mikkotech, promising to sell their product like wildfire if they gave them reseller rights. So Mikkotech concurred. This unnamed reseller (marketer) registeredrepparttar 142883 domain name KeyKey.com (now gone because of legal reasons), but still owns KeyKeyMonitor.com (which sells a highly overpriced and outdated version ofrepparttar 142884 program). Then an unnamed reseller used Clickbank (http://www.clickbank.com) to promoterepparttar 142885 software started selling like hotcakes. But that was justrepparttar 142886 beginning.

Clickbank was one ofrepparttar 142887 web’s first affiliate networks and is still one ofrepparttar 142888 largest. This reseller placed an affiliate program on Clickbank offering a totally, royalty-free reseller rights to anyone who boughtrepparttar 142889 KeyKey application from them. On their site, KeyKey was marketed as a tool to:

1.Find out what your spouse is doing online 2.Monitor your employees 3.Monitor your children 4.Stop intruders and internal data-theft 5.Back-up your work

Numbers 1, 2 and 3 sparked interest in just about every visitor.

But web marketers jumped all overrepparttar 142890 opportunity to get their own brand of KeyKey (with royalty-free resell rights) to sell and programmers made their own versions of Keyloggers and marketed them inrepparttar 142891 same way. These programs very quickly infiltratedrepparttar 142892 web. Programmers were breaching copyrights, stealing codes. Before keystroke monitoring software was created, web spying for under $50.00 wasn’t possible.

These various newly branded “spy software” programs eventually became more professional-looking and efficient, monitoring more than simply keystrokes. Virtual Imagination made a program called Snap Shot Spy (http://www.snapshotspy.com) that used a different approach: It took screen shots of your PC and let you look atrepparttar 142893 images to monitor activity. But this was considered to be primitive by many, because it took up too much disk space and slowed down one’s computer. That technology is more efficient today, however, spy software has continuously evolved.

Inrepparttar 142894 late 90’s, Spectorsoft (http://www.spectorsoft.com/) and Spytech Web maderepparttar 142895 two most robust, feature-rich programs that have been copied for years and still are imitated to this day. Their programs were: Spector, Eblaster and SpyAgent (http://www.spyagent-spyanywhere.com). These programs are amazing! They monitor and capture everything: Keystrokes, screenshots, passwords, web sites visited, applications used, Instant Messenger conversations, hidden windows, mouse clicks and more. They monitor every aspect ofrepparttar 142896 PC. Best of all, they run in stealth mode: The program is not visible inrepparttar 142897 start menu, Ctrl-Alt-Del will not showrepparttar 142898 program running and there is no folder for it. And if by flukerepparttar 142899 program is found, it’s password-protected. Ifrepparttar 142900 logs are found, they’re encrypted!

There are also specialized products like ChatBlocker (http://www.chatblocker.com), that is specifically designed to monitor Instant Messengers, and pop3 and web-based e-mail spy software products, like Webmail Spy, EmailSpy Pro and EmailObserver all found on Email Spyware (http://www.emailspyware.com).

Spy Vs. Spy The software facilitated online spying and made it available and easy-to-use forrepparttar 142901 general public. And it was almost impossible to get caught. That has since changed. After Trojans and Virus Worms ran rampant acrossrepparttar 142902 web and e-mail systems inrepparttar 142903 early 90s, there was an explosion in what market? Anti-Virus of course!

Anti-keyloggers quickly becamerepparttar 142904 product to combatrepparttar 142905 growing number of spy programs available torepparttar 142906 public. Privacy was being abolished and it was not atrepparttar 142907 hands ofrepparttar 142908 CIA, NSA or James Bond (who supposedly do it for their profound love of our great Western nations), but atrepparttar 142909 hands of our spouses, neighbours, parents and employers. Sure there are some instances where keyloggers come in handy, butrepparttar 142910 anti-spy software market was just too much of a goldmine for developers to ignore.

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