Re: power mosfet without diode ?




"exxos" <exxos@xxxxxxxxxx> wrote in message
news:42680683$0$297$cc9e4d1f@xxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> "Vidar Løkken" <njus@xxxxxxxxxxx> wrote in message
> news:JpT9e.5591$4c.733619@xxxxxxxxxxxxxxxxxx
> > exxos wrote:
> >> Subject says it all really, each power mosfet I find has a internal
> >> diode, anyone suggest and 100V 10A devices without diode ? Nobosy seems
> >> to make um like that :-\
> >
> > MOSFET's don't handle spikes. The diode is to protect from spikes in the
> > opposite direction of the applied voltage, when using coils and such.
Why
> > is this a problem for you?
> >
>
> Becasue as per my other post, I am using one to soft start a supply rail,
> the problem is when the mosfet turns off, the smoothing capacitor's charge
> is flowing though the diode and keeping the mosfet from turning off..... I
> guess I will just have to block the reverse voltage with another diode..

or perhaps two mosfets in series with one "backwards"?


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