I found this online that i am building as a simple function generator, i have buult the first two oo amp sections and have got very nice squarewave and triangular waves at the relevent pins, however they are not quite symmetrical.....i need a 1:1 mark space ratio, can someone tell me which component here controls that please so i know what to fiddle with?

Neil

 

The R1/R2 potential divider sets the mark/space ratio.

 

Thanks Albert...seems strange that the authors of this circuit didnt make the M/S ratio 50/50 since it is designed to be a funtion generator

 

The duty-cycle will vary some, just due to the unit-to-unit tolerances in the devices.

 

If you need an absolute 1:1 ratio you can divide the square-wave by two with a flip-flop but that, of course, halves the frequency.

 

I dont need absolute accuracy since its only going to be for home bench use, i'll change R2 to 82K and i think that will be accurate enough.....

Neil.