Re: An extremely good MOSFET driver

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:

> [snipped]
> >
> > BTW, why would you want to turn on your MOSFET slowly???  Doing this
> > will
> > most likely put the FET in its linear operating range and start
> > really
> > heating it up.  You want something really fast.
> >
> > Dan
> 
> [snipped]
> 
> I'd love to turn them both off & on blazingly fast...except that if I do
> that with any given pair of them, then both transistors of the pair find
> themselves on at the same time while one is turning off & the other, on.
> That shorts out the power supply during that instant of time. 

	That's a NO NO!!!  A friend of mine who does power supply design for a
living says you can get driver IC's which provide the necessary time
delay between pulses, but I haven't gotten a typical part number as yet;
will check with him and post that here if someone else hasn't done so
already.  Same problem happens with push-pull self-excited transistor
inverters, of course, and makes the transistors get HHOOTT!

Ed

Ed

> I notice,
> in your circuit, the other secondary winding, and suppose that it drives
> an identical MOSFET circuit, which perhaps is in a 1/2-H configuration
> with Q1.  Do you not have that problem?