RE: Capacitor Selection

["Hawes,Timothy Edward (GEG)" <haweste@xxxxxxx>]

Frank,

Thanks. That's what I was coming around to doing. I don't have the RS part
=
number to hand but since whatever I look at is less than a pound each,
ther=
e's not too much point worrying over a few pence ("high" spec
versus "low" =
spec). I'll look for the lowest leakage I can find and just ignore the
unit=
s :-)

FWIW the voltage regulation chips look to get pretty warm, judging by the
m=
arks on the case above the heat sinks, so the higher temp caps the better
I=
think.

Cheers guys,

Tim H.

-----Original Message-----
From: Frank Mc Alinden=20


Hi Tim
Like James forgotten all my theory.....But i would suggest use =
low leakage and higher temp caps would be better to use i think than
droppi=
ng to the lower temp ones..As Keith D mentioned recently in a post
Electrol=
ytic caps tend to dry up (esp in a hot enviroment) and when they do you
get=
a lot of ac ripple on your power supplies and this causes a hum coming fro=
m the amp.......Drop Keith a line ..im sure he will put you right......

HTH
Frank
----- Original Message -----=20
From: Hawes,Timothy Edward (GEG)=20


James, Andy,

Thanks. I'm still a bit confused though as the "CV" was related
to leakag=
e current i.e. leakage current: 0.01CV or 4=B5A (whichever is greater).

Any thoughts ?

Tim H.
(wishing I'd paid more attention at school now too . . .)

-----Original Message-----
From: James Hoye

> I think I know the equation you're talking about: Q =3D CV.
> As far as I remember, Q is the charge is Columbs, C is the capacitance
=
in
> Farads and V is the voltage (in Volts) across the plates.
>
> Not sure if this helps at all in this instance.

Ooops... I was way out :$

Yes it was Q =3D CV.

Funny how you spend months doing things like AC theory and never actually
seem to use them once you've done the exam.

James H


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