You could also build it with separate THRESH inputs for rising and falling,
lets call them RISE and FALL, and lose the SLEW output.
Just trying to get a "lock" on a variation of my own idea :)
At 12:21 PM -0500 12/05/01,
mark@... wrote:
>
>>a) 3 pots, 6 jacks:
>
>(jacks cost less than pots, LED's draw current and make noise)
>
>1) UP
>2) DOWN
>3) HOLD
>
>6 jacks:
>
>1) UP
>2) DOWN
>3) HOLD
>4) THRESH
>5) OUT
>6) SLEW
>
>The time set by HOLD begins when the rising voltage reaches 5V or when the
>falling voltage reaches 0V. THRESH uses a switched jack. With a jack
>inserted into THRESH, and HOLD set to 0, the falling voltage begins when
>the rising voltage reaches the TRESH voltage, the rising voltage begins
>when falling voltage reaches 5V _minus_ the THRESH input voltage. Got
>that?? Since the falling voltage cannot reach 5V, if THRESH input is 0V
>the cycle is not retriggered. So if the input is a short trigger, it
>cycles once then stops. If the input is a gate, the falling voltage (or
>hold) begins when the gate is released. Note that HOLD also delays the
>onset of an envelope. Modulating THRESH with a voltage can produce various
>functions, including a stepped function similar to S&H.
>
>SLEW output is an output -- OUT run through a simple "degenerative emitter"
>(but without the trimmers or current source). It's more like a lag circuit
>than true sine shaper to save space and money, but it will produce an
>approximated sine if OUT is a triangle.