wrote in news:16ea6110-be19-4a21-aecc-
:

On Jul 2, 3:35 pm, alphamnemonic wrote:
Hi Everybody

This chip normally puts out square pulses. In the power supply I am
working on (http://www.laserfaq.org/sam/150rcsch.pdf) it is putting
out a sawtooth wave. I am testing it in 'standby mode', in which Q4 is
off and R33 is in control of the duty cycle. Replacing the IC1 has no
effect. Does anyone have any ideas?

Where are you seeing sawtooths? Pin 13?

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That is my question. Why do you have output A and output B (pin 11 and 14)
grounded?

Also, pin 13 is VC in for the transistor collectors. Why do you have this
connected as an output?