OT: Simple electronics question...

From: John Lawson <jpl15_at_panix.com>
Date: Wed Aug 4 14:32:44 2004

   Clock radio speaker output reduction:

  Note that a good number of the smaller clock radios use higher-than-usual
speaker impedances. sometimes upward of 60 ohms: saves output devices
having to handle heavy currents (relatively).

   T'were it me, I'd obtain a 500-ohm 'trimmer' pot - the kind that is
meant to go on a printed circuit board, be adjusted once, then left...
500 ohms at 1/4W would be fine - then put it series [one speaker wire goes
to the wiper of the pot, the other goes to one of the 'ends' of the pot]
in one of the the speaker lines (doesn't matter which one) and tweak it
until you have the gain level you like. Pop the cover back on et Voila!
all done. Just get a single-turn one, not the multi-turn type. If you
really want to get fancy, you can put a small switch in the case, and
short out the pot, thus restoring the radio to full volume if desired. If
you could find a suitable volume-control / switch combination, that might
also be a slick way to do this.. but I doubt seriously that a 500-ohm
volume control with integral switch could be found.

  The usual cautions about working on/around mains-connected devices
applies, if the clockradio is in fact plugged right into the wall.


  Cheers

  John


PS: this presupposes you are comfortable with soldering....
Received on Wed Aug 04 2004 - 14:32:44 BST