clock divider schems ...

[media at mail1.nai.net]

Let's hope Yoshi hasn't been scared off by all of this talk of frequency
dividers for VCO's!!  If you want to divide pulse trains used to
synchronize sequencers it isn't that difficult.  There are many circuits
with a 4013, 4027, 4040, 7474, 7473, 7490, 555, etc. that you can use.

I rememmber I was into this whole clock divider diy thing a few years ago.
In fact, I still have all of these TTL and CMOS parts kicking around my
parts cabinet.  The reason I stopped is that I found a used Garfield Dr.
Click and then built an active interface ("The Time Bomb") to hook up the
Dr. Click to my army of x0xboxes.  So I no longer needed to build a clock
divider/multiplier myself.

I looked at some pf my old notes.  My plan was to use a 4040 binary
frequency divider (f/2, f/4, f/8 . . .) with a divide-by-three to get all
of the values I wanted.  I still might build a divide-by-5 or divide-by-7
from 7490's :)  Would you believe that Cubase won't let you do odd meters??


Anyway, I wish I had a scanner.  I have in front of me a circuit that uses
two RC differentiators triggering a 4047 monostable at both edges to double
frequency.  A variable RC network can be built around the 4047 to vary the
duty cycle.

The important thing is to properly interface your TTL or CMOS with the
outside world.  Watch your impedances -- many clock sources can't drive
much of a load.  Be careful not to mix voltages.  A device expecting a 10V
pulse might not sync to a 5V pulse, and a 10V pulse might fry a device
expecting a 5V pulse.  Check the tolerances of any logic IC's that you use
-- CMOS chips have no sense of humor.

PEACE OUT :)
MARK