OT: Simple electronics question...

From: Geoffrey Thomas <geoffreythomas_at_onetel.com>
Date: Thu Aug 5 17:41:21 2004

>
> You could do that. But you might be better off frobbing the
> volume-control circuit itself. The volume control is projbably a pot
> with one side grounded, one side driven, and the variable tap taken to
> drive further electronics. Inserting a resistor in series with the
> non-grounded side will do something like what you want.

I would have thought that placing a low value pot. in series with the
grounded side - say 100 ohm to start with , and turn the radio volume
control to minimum , then wind up your 100 ohm to get the level you want.
The problem you have is at the bottom end of the range of the control - this
would effectively expand that control and not make too much difference to
the impedance of the circuit.
I think you will find that this will work and you won't need to switch it
out as it's effect is minimal.

Geoff.


>
> Either of these approaches runs a risk of creating impedance mismatches
> between the driving circuit and the driven thing. Which way introduces
> less distortion depends on the circuit - though I must confess that I
> would expect the distortion introduced by this mismatch to be far less
> than you get from other causes in most clock radios.
>
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Received on Thu Aug 05 2004 - 17:41:21 BST