I need a power supply that can take 120VAC and turn it into a 20-340 variable DC power supply. I need about 2A at any voltage.

I can use an auto-transformer to boost the 120VAC to 240VAC and then use a variac to adjust the AC and rectify the output, but this is quite heavy and expensive.

Are there any off the shelf high-voltage, voltage regulators that can maybe take 120VAC rectified to 170VDC and buck/boost it to 20VDC-340VDC?

Is there an easy way to do this with silicon and not transformers?

Thanks

 

340 volts, 2 amps; that's 680 watts and it's certainly not trivial to design an SMPS for that voltage, current and power level.

One suggestion: use a voltage doubler to get ~325Vdc from 120VAC; rectify and filter this, then use some SMPS step down circuit to get a lower voltage.

 

Thanks for the quick reply, I should add...

This is to charge an 800μF capacitor bank at most 60 times per minute. So it's not a constant load and it can be pretty crude in terms of regulation.

 

and then use a variac to adjust the AC and rectify the output, but this is quite heavy and expensive.

Not to mention utterly dangerous, as an autotransformer provides no galvanic isolation.

 

This thread needs to be closed, as the current course of the thread clearly violates the safety rules and intent of the forum.

Don't try this stuff at home, folks.