Dear All,

I too tried the same circuit, except for c2 being 1uF / 63v electrolytic cap. On assembling I am getting almost full dc power supply voltage at the output. I changed two ic's , with same result. So I tried simulating the circuit on proteus. Here the output is zero v. I used generator to produce sinewave at amplitude value of 1 & 2 @ 1khz. Changing the value of resistance R6 makes not difference at all.

I am aware this thread is very old. but if any one is watching, pls provide your experience

MOD NOTE: Split from this thread.

 

Are you getting enough signal at the input?
Pins 6 and 7 are connected to an LM393-type comparator. Pin 7 is biassed at half supply. Pin 6 is pulled up to V+.
Pin 7 has to go below half supply to trigger it.
Try biassing pin 6 to half supply with another 10k resistor.

 

Thanks to "MOD" for the note. Because I a limited by very poor mind reading ability the image of the circuit schematic was not clear at all.
If the TS is able and willing to show the circuit being referenced I am sure that a lot of folks will be able to spot the problem.AND suggest a solution.