From: RAYBRO%HOLON@UTRC.UTC.COM (RAY BROHINSKY)
Subject: Re: Footswitch to order
Date: 22 Oct 91 13:25:00 GMT

Footswitches are little different from any other kind of switch
although construction configurations are `optimized' for actuating
them with a foot, rather than a finger.

If you are handy, you can build your own. If you are really handy,
you can build your own from strips of brass and some insulating material:
cut two brass strips about .030" thick into quarter-inch strips, one
about a quarter inch longer than the other. (make that three brass strips,
two the same length, one a quarter of an inch longer than the first two.)

Now cut two 1/4" x 1/2" sections of 1/8" PCboard material. line them all
up even at one end and drill a hole in the whole shebang so you can
screw them all together. The sandwich should be short brass, pcboard,
long brass, pcboard, short brass. You can make the PCboard parts longer
and let them stick out the other side, so you can solder leads to them,
and you may want to use two screw holes (with screws) to hold the whole
thing together in alignment.

Now bend one short strip so it is making contact with the center long
piece, but with just enough force so that it breaks contact with the
center piece if you bend the center piece enough to touch the other
short piece. Now, the one touching the center piece at rest will be the
`NC' or normally closed contact, and the short piece that is not normally
touching the center piece will be the `NO' contact. All you need now is to
make a hinged foot-plate and arrange this assembly so that, when you
step on the hinge plate, it moves the center strip against the
`NO' strip, and away from the `NC' strip. The long one is the `common'
contact.

The reason for this lengthy tutorial on switch-building is to
impress you with how simple a foot switch can be. Also, this points
up the fact that switches can be normally open and/or normally closed.

You first have to determine whether the Prophet600 needs a NO or NC
switch. I don't know from prophets, but Ensonique and Korgs tend to
use the opposite kind of switches, as a friend found out when she
tried to use her korg sustain pedal on her ensonique.

Most foot switches have an industrial-grade switch (called SPDT, for
[ooop...SPST] for single pole, single throw). The manufacturer will have
wired the cable to the common and either the NO or NC contact.
If you get a switch that works backward (sustains when you don't
press the switch, doesn't when you do), you can open it and re-solder
the switch to the other contact. An electrically-minded friend can
do this in less time than it takes to read this post. It's not hard,
but should be done right.

If you can't find out what sense switch is needed for the Prophet at the
local music store, take the board down there, set it up, and try out
his pedals. Most reputable stores will put up with this kind of experiment.
(In fact, I remember Ron letting Gentle Folk come into the store after
hours, set up a PA we were looking at, and doing half a concert
to see if we could make it do what we wanted to!)

Foot switches are the least-sweat element of Emusic.

raybro

 *** Nieder mit den Tueten!  Freiheit fuer Gummibaerchen! ***

From: adamson@ITD.NRL.NAVY.MIL (Brian Adamson)
Subject: Raybro's footswitch
Date: 22 Oct 91 13:57:18 GMT

   In response to:
       "screw them all together. The sandwich should be short brass, pcboard,
long brass, pcboard, short brass."

	Make sure you use a non-conducting screw (plastic, etc) or
electrically insulate the screw from contact with the brass strips.
Otherwise, your all contacts will always be closed.
--
			Brian Adamson
			NRL Code 5523
			adamson@itd.nrl.navy.mil