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I wish to implement a MIDI volume
control. I have not found a suitable
commercial product that does this
other than very expensive digital effects
modules. I wish to control the volume
or gain of a stereo signal using MIDI
expression, which is general MIDI
controller number 11.
So far, I found a kit which converts
MIDI controller levels to a control
voltage. I also found a dual voltage
controlled amplifier kit. But the MIDI to
control voltage module responds only
to controllers number 1 through 8; and
I need number 11. I found a MIDI
module that would convert one
message to another (e.g., controller 11
to the range 1-8), but all together this is
quite an expense.
Richard B. Ahlvin
I need an instruction diagram to
help make a photo cell dusk-to-dawn
unit capable of a 20-1,500 watt 12-36
volt DC application in a small size ( 8-9
mm deep x 15 mm in diameter circular)
that I can encapsulate to make waterproof.
Can anyone help me locate a
source for 365 Variable Capacitors
which RadioShack used to sell as
catalog number 272-1431 and used to
be incorporated in their Science Fair
kits — I've tried eBay but the sellers
want too much for it!.
I have two lead-acid batteries,
never used but two years old that won't
take a charge. I'm sure that they
became sulfated from sitting in a no
charge condition. Is there a circuit I can
construct to desulate them?
#5074 Jack Riggs
I have a couple of old 7.2V battery
operated drills sitting around doing
nothing and have often had a woodwork project where I'm using a couple
of bit sizes, countersink, and maybe a
screwdriver. At such times, a few extra
drills would be useful. I have just rigged
up a rectified DC power supply from an
old transformer to run them. They're a
bit slow but it will do for now. Anyway,
this might make up a simple project for
N&V. My transformer is 120/6.3CT
which gives 9Vrms at the DC end. With
the drill running, I read 6.7VDC @ 1.8A
and loaded I read 5VDC @ 5A.
I haven't bothered with the center
tap of the original battery circuit
May 2007 101