[sdiy] RE: ICL8038

[patchell]

    Technically, you should add a diode in parrallel with each capacitor to keep
it from going reverse polarity.  When you do this, the resulting capacitance is
equal to the value of a single capacitor.....wait, you know, maybe that is not
true.  The diodes would probably make one heck of a strange non-linearity.

    Anyway, IMHO, electrolytics are good for power supply filters, and not much
else anyway.

danial stocks wrote:

> maybe someone could explain the series back to back electros.. they still
> get reverse polarity for 1/2 cyc of ac each.. so why does this then be the
> way of not blowing them up when you need to use them for AC coupling without
> a dc offset?
> Dan
>
> >Non Polar or Bipolar electrolytics are still a loser
> >IMHO for timing circuits. I'd parallel some polys myself.
> >
> >Watch out for ripple current in bipolars... you can still
> >kill them with AC waveforms.... but usually this is limited
> >to speaker crossovers, etc.
> >
> >Some say that returning the center tap of the series caps
> >to the negative rail through a real high value resistor can
> >help keep series electrolytics happy.
> >
> >I don't like 'em... no no!
> >
> >H^) harry
> >
> >
> >>From: "Lappalainen, Janne" <Janne.Lappalainen at silja.com>
> >>To: "'Glen'" <mclilith at ezwv.com>, synth-diy at node12b53.a2000.nl
> >>Subject: RE: ICL8038
> >>Date: Thu, 25 Jan 2001 11:19:07 +0200
> >>
> >>
> >> > -----Original Message-----
> >> > From: Glen [mailto:mclilith at ezwv.com]
> >> >
> >> > At 01:06 AM 1/25/01 , Lappalainen, Janne wrote:
> >> >
> >> > >Can the timing capacitor be made by connecting two
> >> > >electrolytes in series? I don't wan't to invest too much
> >> > money on this by
> >> > >buying large ordinary caps.
> >> >
> >> > I think you meant to say parallel, instead of series. Capacitors in
> >> > parallel will have a larger total capacitance. You simply add the
> >> > individual values together to get the total for the parallel
> >> > combination.
> >> >
> >>
> >>In fact I really meant series, since it makes the electrolytes
> >>non-polarized
> >>(if you connect eg. the + - poles together and - - poles to the circuit).
> >>It
> >>halves the capacity, but it is still much cheaper to buy two 47 uF
> >>capacitors than eg. one 20 uF polystyrene. However, the electrical
> >>properties are not nearly as good as with 'normal' capacitors.
> >>
> >>Janne
> >>
> >>Listen to my music at:
> >>http://www.mp3.com/MountainCowboy
> >
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--
 -Jim
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