SV: Re: SV: Re: SV: Re: [sdiy] BBD clock circuit

[karl dalen]

Who said it was open?

This is straight out of the SG3525 data sheet:

DUAL SOURCE/SINK OUTPUT DRIVERS
output stages are totem-pole designs capable of
sourcing or sinking in excess of 200 mA. The
SG3525A output stage features NOR logic, giving a
LOW output for an OFF state.

So where is the problem?

I got confused when you guys started to talk
 about them H bridges with fotem foyle!

KD

--- jhaible at debitel.net skrev:

> What Harry said ... an open collector or open emitter output 
> won't work.
> 
> JH.
> 
> > Im not so shure what you actually ment or what it is you 
> > trying to achivev but there isnt so many ways to drive a BBD.
> > If you for instance take a 4046 run its vco out trough the 
> > Xor gate then you get the two off phase signals to
> > drive the BBD the same is with switching regulators
> > with the added benefit for adjusting dedband and/ or
> > the actuall pulse width!
> > 
> > KD
> > 
> > --- "JH." <jhaible at debitel.net> skrev:
> > 
> > > >> I saw the gates that prevent overlapping: but the output
> > > >> is just a half-bridge, i.e. two transistors for driving
> > > >> a center tapped transformer for pus-pull operation.
> > > >> For a BBD, I think I need a full H-Bridge - that's why I was asking.
> > > >>
> > > >I think you mean "totem pole" output ???
> > > >
> > > >An H bridge would be a four transistor structure with a floating load...
> > > >you don't need
> > > >that for a BBD (which suck, btw :^) which is single ended at the clock
> > > 
> > > I'm never so sure about using the right words. But if totem pole, then
> two
> > > totem poles (for the two clock inputs). Now in switched power supplies,
> > > you use two totem poles (=  one H bridge) to drive a floating winding
> > > indeed.
> > > So even if in the BBD application you wouldn't call it H-bridge, you
> might
> > > call it H-bridge in a switcher IC that you want to (ab)use as BBD driver.
> > > 
> > > JH.
> > > 
> > > 
> > > 
> > 
> > 
> > 
> 
> 
> 
> 
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