SV: Re: [sdiy] Wanred (dead or alive) : Pot

[Roy J. Tellason]

On Saturday 20 August 2005 07:25 pm, john mahoney wrote:
> > karl dalen wrote:
> > > 4066, 4053,4051, PWM and dead band comparators to set
> > > OFF position! PWM at 100Khz. Gives mix and switch
> > > in many possible ways! Ugh!
>
> Roy J. Tellason wrote:
> > I was wondering a while back whether something of this sort would be
> > workable...
> >
> > Does anybody have any actual circuits that work along these lines?
>
> I've read that the switching frequency must be "much" higher than the
> maximum signal frequency. But, how much is much?
>
> Blacet makes a switched capacitor filter. What's the frequency, John? (Or
> is it proprietary?)
> --
> john <--(highly proprietary)

I don't know how a switched capacitor filter would tie in to this...

I did start to breadboard some sort of a circuit way back when,  probably 
using a 4066 since I have a lot of those on hand.  And the first thing I ran 
into right off was some really *horrible* distortion.  Seems I'd forgotten to 
consider signal levels and such.  To move on with that would have needed me 
to rig some kind of a bipolar power supply that was still within CMOS limits, 
or capacitively couple an attentuated signal,  and I never did get around to 
doing that,  got sidetracked from the project,  and into other things.  Maybe 
one of these days I'll get back to it...