Anyone made a 12v to 2x35v or 40v?

UC3843 is also a good contender, mind you that you might want to buffer the output with a totem pole to drive it more efficiently.


You have not specified noise or current requirements. Also a flyback at these voltages takes some engineering (mostly design and getting the RC snubber right)


Cheers,

V4LVE
 
I've been looking into the same thing. With SG3525, there is this:
Switchmode Power Supply For Car Audio

You can probably do it on perforated board, the schematic is really simple.

What are the advantages of the other ICs people have recommended? I'd be interested in low noise and high efficiency. Not sure regulation is needed. After all, the Hypex SMPS are pretty stiff already, and this would probably get better from a car battery or regulated 12 V power supply.
 
The difficult bit is the transformer build. It is usual to litz wire the primaries with multi-stranded copper rather than thick copper wire or copper strips.

You haven't mentioned the PSU requirements. 100-500W are readily available, any more than that gets complicated.

500W at 12V you'd be looking at some 55A primary current.
 
Last edited:
Magnetic power handling is defined by the cross section and the material type. Copper losses will be defined by the shape of the cross section. Round is ideal, square ok, a high rectangle not so much, even if it might be better for thermal dissipation.

I have yet to find a ferrite toroid with round cross section...