Hello forum members,

I am looking for links/info regarding driver circuitry of PWM circuits;specifically I need information about what electronic discrete parts/I.C.'s,and circuit schema I would need will trigger/vary the Duty-Cycle of of a pwm circuit; that is,what electronic components can increase/decrease "duty-cycle" of project pwm circuit by proportionally increasing/decreasing trigger pulse frequency from project pwm driver circuit??? ∞

Thanks in advance for a reply/link!!typo

 

As in most things electronic, there are lots of ways to do it. Try this example from out Ebook - http://www.allaboutcircuits.com/vol_6/chpt_6/9.html.

Another easy way to do PWM is by using a microcontroller with a dedicated PWM output pin/s.

One note - PWM is generally done by varying the duty cycle of a pulse at a fixed frequency.

 

Hello beenthere,
Thanks a lot for the link to the ebook;very informative,but I basicly know how a "pot" control sub-circuit operates for the pwm circuit!

What I am looking for,specifically,is a control sub-circuit for OPAMP/Comparator/
PWM IC that can vary the duty cycle as a one-shot,monostable vibrator can do,but also vary the duty-cycle of the pwm circuit PROportionally by the change
of this electronic projects pulse train frequency!!

Sorry for the long explanation,but there has got to be a trigger/control circuit for varying the duty cycle(F to V converter???) proportionally to the input pulse frequency,but as of yet,I have come up empty on my "pwm project" quest!!∞

Thanks a lot,however,for your reply;I will probably check epanorama's website for possible solutions for my needed pwm control circuit components since a potentiometer duty-cycle control,in itself,won't help me with my pwm
electronics project!!

 

Hello beenthere,
Thanks a lot for the link to the ebook;very informative,but I basicly know how a "pot" control sub-circuit operates for the pwm circuit!

What I am looking for,specifically, is a control sub-circuit for OPAMP/Comparator/
PWM IC that can vary the duty cycle by one-shot ,monostable vibrator controlled input , and can vary the PWM duty-cycle proportionally by the change of this electronic projects pulse train frequency(instead of the potentiometer normally as the controller input to a pwm circuit;possibly with a hall-effect sub-circuit as part of the input control??)!!

Sorry for the long explanation,but there has got to be a trigger/control circuit for varying the duty cycle(F to V converter???) proportionally to the input pulse frequency,but as of yet,I have come up empty on my "pwm project" quest!!∞

Thanks a lot,however,for your reply;I will probably check epanorama's website for possible solutions for my needed pwm control circuit components since a potentiometer duty-cycle control,in itself,won't help me with my pwm
electronics project!!

 

If you can generate a pulse train, why not use it for the PWM control directly? Microcontrollers are just made for that sort of thing.