Hi Bob,

long time no talk. this is for vw bug no advance, no injector, no retard
no thing
just basic fire. in stead of point uses hall effect. not instead of direct
firing like i am showing in attachment coil "on time" needs to be changed
like PWM duty cycle change but the frequency of pwm should be same as
input and input start should be synchronized
like the picture shows. I think using external timer as clock source and
software pwm should solve the problem unless I am wrong.

thanks bob

Andre


>
> On Mon, 24 May 2010 11:44:11 -0400, andre said:
>
>> I have question that I am kind of stuck. friend of mine asked me to make
>> small board for his vw bug that has 1 input and 1 output. the input
>> takes
>> pulse (4 pulse is 1 cycle) the frequency goes from hz to khz at this
>> moment is unknown so the pic reads the pulse and output changes on time
>> only ( in this case called dwell control)
>
> Hi Andre,
>
> Is the application an ignition dwell extender, or is it ignition timing
> retard, or is it for fuel injection?
>
> I have seen dwell extenders for old-style ignition systems that used an
> SCR to electronically close the points(charge the coil) after a short
> delay. The SCR resets when the real points close. When the points open,
> the spark happens, then the SCR charges the coil again, etc. Is this
> something like that, but with a PIC?
>
> Cheerful regards,
>
> Bob
>
>
>
> --
> http://www.fastmail.fm - mmm... Fastmail...
>
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>


-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist