Re:info about driver circuitry of PWM circuits

Discussion in 'The Projects Forum' started by robo5050, Feb 11, 2009.

  1. robo5050

    Thread Starter Member

    Dec 6, 2007
    15
    0
    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??? ∞:confused:

    Thanks in advance for a reply/link!!typo
     
    Last edited: Feb 11, 2009
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    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.
     
  3. robo5050

    Thread Starter Member

    Dec 6, 2007
    15
    0
    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!!
     
  4. robo5050

    Thread Starter Member

    Dec 6, 2007
    15
    0
    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!!
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    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.
     
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