design a SMPS 220V to 3 Output

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Thread Starter


Joined Jan 23, 2020
I have to design 2 Power Supply SMPS 220v AC to 3 output each one 3A
first one : 12v - 9v - 5v
second one: 12v - 7v - 5v
unfortunately, I don't have experience in that

so someone can help me ?

thanks in advance


Joined Jun 22, 2012
You're better off using a ready made switchmode psu like an Atx and putting regulators on it, otherwise you're starting a fresh design and hassle ! ,

You can look at smpsu chips like the UC3844 series, or TL494, Viper22a-e series..


Joined Jul 29, 2018
Offline supply design means coming up with a custom transformer, that could be a serious sourcing issue for a one-off project. Not to mention the safety issues of proper insulation, spacing, and creepage distances. I've repaired off-line supplies, designed many DC-DC supplies, and generally avoid doing any off-line designs because of all the safety standards and testing involved. Consider purchasing a quality commercial supply that puts out 15-18V at 8-10A and add a simple 5A rated buck design for each needed 3A output.
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