Re: small inverter driver chip


"Harry Dellamano" <harryd@xxxxxxxxxxxxx> wrote in message
news:pNBhg.6720$Id2.5804@xxxxxxxxxxx

"Terry Given" <my_name@xxxxxxxx> wrote in message
news:1149653067.778644@xxxxxxxxxx
Clifford Heath wrote:
Terry Given wrote:

its piss easy, I shouldnt need to draw a picture.

- make a single-ended forward converter.
- bung a p-fet in between the +Vdc supply and the winding
- connect its gate to the drain of the lower N-FET
- slap a diode from P-FET drain to 0V (anode to 0V)
- slap a diode from N-FET drain to +V (cathode to +Vdc)

voila, now you can throw away the reset winding and diode.

either both FETs are on, and current flows into the winding,

or both FETs are off, and the mag current commutates back to the supply
thru the 2 diodes.

limit duty cycle to 50%


Cheers
Terry

Nice, ...your 50% limit is because of the diode from N-FET drain to +Vdc.
Remove cathode from +Vdc and tie to a storage cap to ground. This output
forms a boost circuit. Set duty to 75% and get OPs 30V boosted output.
Windings on inductor/transformer will generate the other voltages needed.
POC!
Harry
Err.. But a simple boost configuration from 10V to 30V beats all. Set duty
to 67%. Use the two N=2 winding in parallel for the primary boost inductor.
Use the two N=1 winding in parallel, half wave rectify for -5VDC.
Send bottle of Tequila to Harry for this design effort.


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