[sdiy] 'reset' for multivibrator LFO?

[Paul Maddox]

Nick,

> hey there, i'm working on a few additions to the standard
> 2-opamp multivibrator LFO circuit, one feature i wanted to add
> was a reset (or sync-to-tempo), basically when you hit a
> momentary switch the LFO would go to either the high or low
> voltage and start to ramp from that point. how i was thinking
> about doing it was to connect a point in the loop to ground or

To do this simply add a FET switch accross teh intergrateing cap.
Takle a look at any sawtooth VCO and you'll see a FET across the cap.
fed from a fast opamp (LM311)  which is acting as a voltage senative switch.
Simply add a cap to this input and there you have (if you find a VCO with a
sync input,
then this is also shown)..
Just dont connect the output of the intergrating opamp to the reset opamp
(LM311)
and you're there..

Paul
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