Generating +/- 170VDC From 120Vac

[Scubasteve]

Hey all,

I want to generate + and - 140-170Vdc via an ac outlet. I know that you can use the standard bridge rectifier to get this straight from the AC outlet with some filter caps to get the 170Vdc positive max. output. I need a -170Vdc supply that will have a ground reference the same as the +170Vdc. I don't want to use a transformer whatsoever, because of the cost factor. I need approx. 1.5-2A continuous at these voltages, so you can imagine the cost of using a centertapped 220Vac transformer.

Can I use a bridge rectifier and reference the positive output (negative side) to ground of the positive 170Vdc, will this give me the negative voltage? Or will it blow up in my face :shock:

Thanks a lot!!!,

Steve

 

[Sebi]

First: be careful, without transformer all components of Your circuit on mains voltage, and 0V not equal to GND!
Fig1 a crop from computer supply circuit, Fig2 the voltage doubler circuit,equal the Fig1 if switch in 110V position.

 

[Chippie]

Errm, in the lower picture,

the diode at the bottom is the wrong way round, the cathode should be connected to the anode of the upper diode, effectively they are in series, then the common point is connected to the AC supply...

 

[Sebi]

Thanks, Chippie i've corrected it...

 

[Chippie]

LOL......thats ok, easy done

 

[Scubasteve]

First of all, thanks Sebi and Chippie for your help, it is appreciated!

I will be doing some simulation in PSpice in order to determine the ripple and the values needed for the capacitors and resistors.

Thanks again!

Steve