"TeGGeR®" > wrote in
:

> jim beam > wrote in news_-dnS91tZMHfzHfRVn-
> :
>
>> wrote:
>>> TeGGeR® wrote:
>>>
>>> http://www.tegger.com/hondafaq/ignit...ion/index.html
>>>
>>> Hopefully this is correct now.
>>>
>>> Thanks to all for their help, especially Jim Yanik.
>>>
>>> --
>>> TeGGeR®
>>>
>>> The Unofficial Honda/Acura FAQ
>>> www.tegger.com/hondafaq/
>>> --------------------------------------
>>> I think in the 1990 Honda Civic, the igniter also provides
>>> for for some PWM control.
>
>
> "PWM" control?

Pulse Width Modulation.

>
>
>> It senses the back EMF and
>>> kills the coil drive at the correct momment to insure a
>>> hot spark.
>
>
> Do you know the mechanism by which it sees the back EMF?
>
>
>
>>> I played with an ignitor and couldn't get it
>>> to because correctly until I connected to to a Honda
>>> igntion coil. As I varied the frequency of the drive pulses,
>>> all the same width, the output created wider pulse at higher
>>> "RPM".


I suspect the IC inside the igniter controls coil current,by means of
varying the pulse width(that PWM).
I haven't looked for any IC app notes to see exactly what they're
doing,though.If anyone has a URL for an app note for these Ics,I'll go
look.


>>>
>>> Terry
>>>
>> interesting! i'd read that they did that, but just haven't had the
>> time to sit down & test for it. thanks for the confirmation!
>>
>>
>
>
> So how come my news server has this message, but not Terry's?
>
> And yes, that's one of the very nice features about electronic
> ignition versus Kettering. With Kettering, the very moments you need a
> fat spark are the very moments you get a weaker and weaker spark since
> the system has no way of increasing dwell time to compensate for RPM.
>



--
Jim Yanik
jyanik
at
kua.net