Additional Injector Controller

[Ian Habicher]

>There should be lots of app notes and data sheets for the 555 on
>national semiconductors WWW page.  You can set up a circuit where a
>variable voltage controls the duty cycle output.

Yup!  That's the idea.  I want the thing to generate a pulse that gets 
longer with higher MAP sensor voltage.

The thing is, as the engine runs faster, the pulses get closer together.  
This is good, as it provides RPM compensation.  (Less time between pulses 
without changing pulse length).

But I don't want the actual pulse length to change as the RPM changes, only 
with varying MAP sensor voltage.  Is this hard to do with a 555, or are they 
pretty stable with regards to varying pulse length due to pulse frequency?

The SDS additional injector controller works like this.  But it's 600 bux 
Canuck!! :(  And I bet it has a $2 555 in it :)


  synchronizing it to
>another injector might be more complicated.

Should it be?  I just want the existing injector pulse to trigger the AIC 
pulse, that's all.  Or, I could use a tach or ignition signal.  My Wankel 
engine's leading ignition fires once every half-rev, which is perfect.


  While you're there look for
>op amp notes also, between the two you should be able to get what you
>want.
>
>--steve

Thanx man!

Ian
87 RX-7 Turbo II
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