90 to 510 vac input bias supply

Posted by: Rono on 09/21/2009

I have a very wide range input application requiring a non isolated 5 volts 20 ma. source of power from a 90 to 510 vac input line . Is there any past applications information that I might take advantage of to get this done .

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Take a look at the STACKFET arrangement. It basically connects 2 MOSFETS in series and distributes the VDS during the off time across these MOSFETs thereby allowing you to increase the input AC voltage. search for "STACKFET" on the www.powerint.com website or
See this thread for details
http://www.powerint.com/forum/power-supply-design/high-voltage-input-stackfet
http://www.powerint.com/en/community/papers-circuit-ideas-puzzlers/circuit-ideas/-high-voltage-input-switching-power-supply-usi

How do I design a transformer for a StackFet design that can work from 580VAC?

The Pi tools do not alow a design from such a high voltage

Yes PI Expert and PIXls do not allow you to design with such a high voltage. However PIXls will at least allow you to input such a voltage. (PI expert wont allow you to proceed with the design)
So my suggestion is input the design in PIXls, and ignore the VDRAIN warning which will show up because the spreadsheet assumes that the breakdown voltage is 700 V. With Stackfet this voltage is actually higher. So you have to make a design decision based on the calculated VDRAIN value as to what should be the BVDSS rating of the discrete MOSFET in the Stackfet arrangement.