Multiplexing a full wave rectifier!

[Bjorn Julin]

> > Is it insane to multiplex a full wave rectifyer?
> >
> > My intention was for a usage in a frequency/pitch shifter
> > application to multiplex a rectifyer at aprox 100khz
> > among a couple of channels.
>
>My answer would be like this:
>
>Yes and No.

Me to, first i was sceptical, but!

>Yes, if you would have to set up hardware just to do the multiplexing
>I think it will be more effort than just making several precision >full 
>wave rectifiers.

I have the oposite feeling, if one spends time to do it right
in this application i will save a lot of componennts (goal1)and
setup time, calibration time, and solder time. (goal2)

>No, first, the rectifier function as such is not a very time >dependent 
>thing, so you don't build up much of a state as you
>do in say filters.

Hmm, takling about filters, is it insane to multiplex a allpass
among a bunch of channels? I dont need to go above 12Khz!

>However, you naturally causes filtering effect due to the sampling
>effect. Also, a envelope follower would be sligtly receptive to
>glitches when you go from low-to-high or high-to-low values.

Sampling effect is the minor problem in this app.
Hmm, glitches, the rectifyer are in front of the mux?

>If it is just to make better use of the rectifier hardware, then I am
>leaning to the more doubtfull level, where as if you really just want
>diffrent inputs you surely should go ahead.

I want o save "lots and lots of components" thats why i want
to multiplex.

>These are just my views after thinking a few cycles on the problem.

Reg
BJ
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