I want a PWModulator with 555 Timer IC. When I searched all I got was designs that needed you to turn Pots. I want control signals to do this. If I directly use pin 5 of 555, it will also vary the frequency, which I don't want.
@4pyros Control Signals from other parts of the circuit (Magnetic Levitation System, the other thread).
I don't know why but I couldn't make that circuit (eric's link) work. In particular, even when I applied close to 0 V to the control pin, the output duty cylcle isn't 0. I want the output duty cycle to be 0% when I apply 2.5 Volts and then 100% when I apply 10 Volts to the control pin; and I want it to varry linearly.
As far I know the 0% and 100% ratio cannot be achieved when using a 555 PWM, it can be very close.
What ratios did you achieve on test.?
It can when using the 555 as a schmitt trigger into a comarator. such as this; Bill Marsden's PWM circuit - All About Circuits Forum
Thanks for the pointer, I only hope the OP reads your post.!
Looked at the link, its a commonly used circuit but it does require more that just a 555 ie: a LM339 .