So this is what I have got so far, I can use the 555 in Astable operation, I have drawn up a quick schematic, all I then need to do is take the output through something like a 74hc14 to invert the output to give me the NOT PWM signal...
Period is 0.693(R1+2R2)C
So freq would be 1/Period
By changing R1 and R2 to a pot I should be able to change the duty.
Am I close or way off ? |