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colin colin is offline
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Default I wonder if this will work - Inverter.jpg


"John Larkin" wrote in message
...
I need to make -12 from +12, at maybe 500 mA, and all the obvious
inverting switching regulators suck for one reason or another.

The LM5112 is a 50-cent fet gate driver.


another thought,
how about a self oscillating one with a nch mosfet,
if its a steady 12vin and 12v out it should be doable with ~50% duty cycle
so just an extra winding on the inductor.
ofc with a bjt you need less turns for the base drive.
and some bias to start it up.
not sure if you could add current limit easily,
maybe when the inductor saturates it would lose base drive
(havnt given this much thought)
a 3pin device (tl434?) could shunt gate drive to regulate voltage further.

Ive also used one of those uc3843 to drive a transformer directly with no
mosfet.

Colin =^.^=