AUTO-MANUAL CLOCK GENERATOR

[sheldonstv1]

This is part of my current cctv camera mux its a very reliable circuit which has been in use for many years since i designed it.....

View attachment 39014

 

[sheldonstv1]

the supply connections for the 4093 are pin 7=0v,pin14 =+12v.......

 

[audioguru2]

Hi Sheldon,
You have a nice circuit. ;D
Shouldn't the transistor have a resistor between its base and emitter to quickly turn it off? About 22k would be fine.

 

[sheldonstv1]

;D yes that would ensure rapid turn off-but ive not had any problems with it ,the circuit seems to work quite well without it present....its been in use for quite a few years now with no failures.......the circuit is so simple there isnt really a lot to go wrong.
regards mike