EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: alah on November 26, 2018, 07:18:16 pm
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Hi ALL; I have a 19v / 2A power supply which is blown.
Id like to use the filtered DC and the HF xfrmr to build one. I have VR 431 and foto transistors but I need a simple circuit for the feedback. Im googling SMPS circuits and though I understand the basics of SMPS, I need some help. Thanks, Alberto from Venezuela.
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The UC3842 is a basic flyback controller IC. It is still commonly used in cheap SMPS from China. What it mainly lacks compared to modern IC is the power saving ability when lightly loaded, green mode.
If you choose the UC3842, be certain to put a 10K resistor between Gate and Source as well as all of the other things that you simultaneously must get right.
Tell us more about the existing design.
Extra; assuming that is the original is the flyback type.
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Also, do you have the equipment to do this project safely? Isolation transformer and Variac.
You also must have an oscilloscope, not to have one is working blind.
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Im working on a design ( not mine ). As soon as I have sufficient details Ill be back, Thanks.
Oh, I dont have an oscilloscop and believe I never will.