[sdiy] current question

[Gene Stopp]

If the first core is a tri-square core (integrator/comparator) you can do this to get a half-frequency triangle waveform:

Drive a flip-flop with the square wave to get a sub-octave square wave
Use this square wave to invert/don't invert the triangle wave
Sum part of this square wave into the resulting wave to get a suboctave triangle

I submitted this to EN long ago (actually it was thru my friend Iggy Foulke who was the actual subscriber at the time)

- Gene




At 03:04 PM 7/26/2007, harrybissell at wowway.com wrote:

>I'm imagining what you might be trying to do and can't think
>of a real simple way

Yeah, I imagine that what I'm trying to do matters a great deal. :-) 
OK. I was trying not to go there -- better to test one's possibly 
dumb ideas in private! -- but my idea is this:

Can we make a "dual core" VCO? (To borrow a term from modern 
microprocessors.) One core would behave normally, while the second 
would run at half the rate of the first. The second core would be 
hard synched to every other cycle of the first core so that it would 
run at exactly half the rate. The goal is to produce a suboctave 
output that's not a square wave.

Another way to put this is that the second core is a relaxation 
oscillator that's reset by a square wave suboctave of the main core.

Heck, this doesn't even need a second current source, does it? The 
second core can simply charge to twice the voltage of the primary core.

Is this as trivial as it seems to be?
--
john