Re: Flyback Driver PCBs

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Mitchell" <electrontube-at-sbcglobal-dot-net> 

Yeah I just found out the aluminum based PCBs are about a grand for a few of
them,  forget that.

This circuit can handle whatever voltage the transistors you put it in it
can handle.  I used FDH44N50 mosfets and could pump 500v into a flyback if I
wanted too,  but they start to arc over at 25v on the primary.  The circuit
uses a gate isolation transformer.    I am making it 2oz copper instead of
1oz,  and the tracks are super thick.

Regards - Jim Mitchell
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, April 12, 2004 6:07 PM
Subject: Re: Flyback Driver PCBs


 > Original poster: "Eastern Voltage Research Corporation"
<dhmccauley-at-easternvoltageresearch-dot-com>
 >
 >
 > How are you driving the upper fet of your half-bridge?  Hopefully you have
 > some sort of isolation in there (transformer) to drive it
 > if you are switching more than 30-40VDC.
 >
 > Also, aluminum based PCB? ? ?  "Large currents the bridge will be
 > switching?"  This can all be done just fine on a small PCB board.
 > I've designed and built numerous circuits on simple 1oz copper boards that
 > could take 20A of current.  Just use thick copper planes as
 > traces and double up on top and bottom layers.
 >
 > And if by aluminum you mean an IMS type substrate board, there is no
reason
 > in the world to be doing something like that.
 >
 > Dan
 >
 >
 >  > Okay!  at least some people want them!  The board looks really good,
only
 >  > 3.5 X 4.5 and has everything but the low voltage transformer, and the
high
 >  > voltage power to the flyback primary.
 >  >
 >  > I sent the quote in today hopefully they'll get back to me later today.
 > The
 >  > PCB will be aluminum based (I hope) so it will be able to carry the
large
 >  > currents etc that the bridge will be switching.
 >  >
 >  >
 >  > Regards - Jim Mitchell
 >
 >