Ion Gap Sense Questions

[Rod Barman]

>
>Rod asks

>
>This is a very interesting point.  I would guess that the capacitor sits
>in series with the secondary circuit between the current sense resistor
>and the secondary coil, with a clamp zener in parallel.  

This is my guess too.  Pretty clever setup.  

>> Aswell, any more info about high tension measurements?  How this
>> would be done without frying everything in sight?
>> 
>
>Inductive pickups?  Standard part for many oscilliscopes.

Hmmm .... I think you'd want a Hall effect sensor here for measuring
currents at both low and high frequency.  I'm not sure that would work
too well either.  In addition, the bias voltage still has to be 
injected somehow.  

The reason I'm interested in high tension measurement is that it
would make putting the system on an engine with a distributor-based 
ignition system possible.


>Note that in a similar paper by researchers at Chrysler (SAE 950003), they
>were able to process the signal with a simple integrator feeding into one
>of the A/D ports on a HC11.  Misfire detection (in this case) was a trivial
>task of reading the port and comparing the digital input to a threshold
>near zero.

I saw this too and it looked simple but effective.

>Robert 'it looks like it's time to convert to multiple coils' Dingli

Any suggestions on what's a suitable available coil for this?

--
Rod Barman, IRIS ISDE-6 @ Laboratory for Computational Intelligence
University of British Columbia
rodb at cs.ubc.ca