How to test A Relay

Repairing Motherboard of PC and Video Card

motherboard of pc

video card

video card

Bulged electrolytic capacitors

Capacitors that were replaced from video card and motherboard of pc. Just look at physical appearance of 

electrolytic capacitors by replacing some capacitors this motherbooard and video card of pc can back to life.

Jestine Yong Articles On EzineArticles

If you want to read the past electronic repair articles by sir jestine yong, you can click on the link below.

http://ezinearticles.com/?expert=Jestine_Yong

What Power Supply Do I Need?

http://www.smps.us/what_power_supply_do_I_need.html

We always here what power supply do i need? Find out here.

FRONT of HOUSE - January 2011

http://digital.turn-page.com/issue/22659

http://digital.turn-page.com/issue/22659

Click on the link above if you are in recording or recording engineer and looking for recording equipment see this FOH Magazine.

LCD Monitor Repair

                                              http://www.lcdmonitorrepairebook.com/

Click on the link to learn how to repair Phillips LCD Monitor 170B No Power Systematically.

PC USB Connectors Pin Out

Anatomy Of A Lightning Strike

Visit the link below. This articles tackles about surge protection.
http://www.mcgsurge.com/pdf/The%20Truth%20of%20the%20Matter2008.pdf
http://www.mcgsurge.com/pdf/catalogs/299-300-10_DATALINE_Vol2.pdf

Information On Basic Testing of Semiconductor

If you would to know more on basic testing of semiconductor. Visit this site. It is important to be confident and knowledgeable in testing every electronic components. Click on the link below.http://www.repairfaq.org/sam/semitest.htm

Circuit Exchange Links

Visit this website.

Circuit Exchange Links

Altium Presents: Component Management

Books for Free

I f you visit the link below you can download some books for free that will help you. I dont know if it's legal i hope so. If you want to add more knowledge in electronics visit the site to download some. It will bring you to some link in their website.

http://www.ebooksdownloadfree.com/Languages-and-Culture/Newnes-Guide-to-Television-and-Video-Technology-Fourth-Edit-BI7697.html

Quick On-Board Junction Test

Circuit operation:


Both inputs of IC1A are connected together by two equal value resistors (R4 and R5) and to half the voltage supply obtained by means of the voltage divider R2 and R3. So, the same voltage should be present at both input pins.

In practice, half the voltage supply (i.e. about 4.5V) will be present at the inverting input (pin #2) of IC1A, but the constant voltage generator formed by R6 and D1, feeding the non-inverting input (pin #3) of IC1A by means of the voltage divider R7 and R8, clamps this pin to about 4.1 - 4.3V: this will cause the output of the op-amp to stay low.

If the circuit input (R2 to R3 junction) is shorted to negative ground (a condition equivalent to a shorted transistor junction) pin #2 of the op-amp will go to 0V and the voltage at pin #3 will decrease to about 0.3 - 0.35V (caused by the constant voltage generator mentioned above): the op-amp output will go high, activating the piezoelectric sounder.

When a real transistor or diode junction is connected to the input of the circuit instead of shorting the input probes directly, the piezo sounder will emit only a short single beep just as the probes will come in contact with a good junction, due to the time delay provided by the discharge of C2 when the voltage at pin #3 is falling from about 4.1V to 0.3V.

To provide a better signaling system, Fet Q1, IC1B and related components were added. This op-amp is wired as a 1Hz square wave generator and Q1 acts as a solid-state switch, going on and off one time per second having the Gate driven by the op-amp output. In this way, the junction of the device under test is connected and disconnected to the voltage sensitive circuit built around IC1A one time per second and the result will be a clearly audible train of short beeps signaling the good condition of the junction or track under test.





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http://www.redcircuits.com/Page133.htm

How to test IGBT Using Digital Meter

Global Sources E-Magazines

You can subscribe this e-magazines. Go to globalresources.com. Click here to see inside of this january issue. http://akamai.globalsources.com.edgesuite.net/f/593/3445/5d/beverly.download.akamai.com/3445/mag/Electronic_Components.PDF?source=MNtfcnEmail_20110103&magpos=emag_20110103