Comments on: UC3842 Test Circuit https://jestineyong.com/uc3842-test-circuit/ Semiconductors, Test Equipments, Circuit Board Troubleshooting, Electronic Repair Courses and Many More! Sun, 15 Jan 2023 07:54:48 +0000 hourly 1 https://wordpress.org/?v=5.4.19 By: Jestine Yong https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-399336 Sun, 15 Jan 2023 07:54:48 +0000 https://www.jestineyong.com/?p=194#comment-399336 In reply to jay.

Hi Jay,
Check the filter cap along the VCC line or direct replace the power IC and retest.

Jestine

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]]> By: jay https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-399091 Thu, 05 Jan 2023 22:20:48 +0000 https://www.jestineyong.com/?p=194#comment-399091 In reply to admin.

justin help

3842b vcc is not stable 11 to 14v
output pin is trying to produce square wave but its collapsing ..please help

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]]> By: Jestine Yong https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-137723 Mon, 22 Oct 2012 14:26:48 +0000 https://www.jestineyong.com/?p=194#comment-137723 In reply to oleg.

Hi oleg,

You can use bank transfer if you need the ebooks. In your case of high voltage check the components surrounding the secondary side of optoisolator IC especially resistor that will turn into high ohm.

Jestine

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]]> By: oleg https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-136014 Sat, 20 Oct 2012 00:37:26 +0000 https://www.jestineyong.com/?p=194#comment-136014 Hi Jesting!
Thanks for the suggested link, but i already readed it. It is very useful link but no covers all the true cases i founded in the real world. Also thanks by suggestions on the ways to buy your ebook, but neither are suitables for me. Keep in mind that i need abut 3 months of working to complete thats money. Also Western Union here is to receive, not to send money. Thanks any way.
Well, talking about my similar Sunny ATX-230  power supply the problems is that the output voltages are to high. I shorted the FPO 3rd pin of LP7510 to ground an then the PS started. When measured the output voltages were as following: 12V altered to 17V, 3,3V altered to 6,6 and 5V altered to 7V. That's the cause why PS start, then stops.
Any idea? Any Suggestion?
Thanks in advance,
Oleg.
 
 

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]]> By: Jestine Yong https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-133653 Mon, 15 Oct 2012 14:08:23 +0000 https://www.jestineyong.com/?p=194#comment-133653 In reply to Lee.

Hi Lee,

Sorry i do not have buck boost schematic.

Jestine

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]]> By: Jestine Yong https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-133640 Mon, 15 Oct 2012 13:11:29 +0000 https://www.jestineyong.com/?p=194#comment-133640 In reply to oleg.

Hi Oleg,

You can use try use western union or money gram servicesor even bank transfer. As for the atx power supply repair you can try this link:

http://www.repairfaq.org/sam/smpsfaq.htm

Jestine

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]]> By: Lee https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-133523 Mon, 15 Oct 2012 02:47:50 +0000 https://www.jestineyong.com/?p=194#comment-133523 Verror-you search datasheet of IC UC 3842 ,it will help you show .!
Do you have schematic buck-boost use Ic uc3842?
I have a project : power converter
in put : 9-19V use buck-boost converter with ic uc 3842
out put: 12V-4A
Can you give me schematic buck-boost with ic uc 3842 ?

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]]> By: Jestine Yong https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-133410 Sun, 14 Oct 2012 17:42:34 +0000 https://www.jestineyong.com/?p=194#comment-133410 In reply to lee.

Hi lee,

Could you elaborate the meaning of verror?

Jestine

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]]> By: lee https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-133137 Sat, 13 Oct 2012 17:43:24 +0000 https://www.jestineyong.com/?p=194#comment-133137 please..! Can you tell me about Verror of UC3842 ???thank

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]]> By: oleg https://jestineyong.com/uc3842-test-circuit/comment-page-1/#comment-132912 Sat, 13 Oct 2012 02:04:21 +0000 https://www.jestineyong.com/?p=194#comment-132912 Hi Jestine!

Definetively i need your SMPS repair ebook, but i have no way to buy it, i am a cuban engineer and here there is not way to pay online. Could you help me please with some free materials about atx power supply repair??? The materials i founded on the web are very basic troubleshootings techniques and not going deeper in other problems i founded on atx smps like regulation voltage problems, over or under voltage protection, to high standby voltage, etc, no drive signals on PWMs or supervisor, etc

Please, help me with something you can.

I'll really high appreciate it.
Regards,
Oleg.

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