Ignition Controllers

[Stuart Baly]

Tim wrote:
>At what frequencies?  It depends on the engine, which is why I didn't
>include this feature in my system.  Engines knock and resonate at
>different frequencies. You can look at all the technical papers you
>want (and this is a good idea to learn how knock detection works) but
>unless you see one for your application, the frequencies may be a
>little off.

I remember reading a formula somewhere that relates the knock 
frequency to the engine bore. It was a simple thing like Knock 
Freq=Constant/Bore. I'd guess that the frequency would change with a 
turbo engine as the speed of sound would change with gas pressure. 
Anyway, this is of no use at all to a rotary engine.
	I might just take a large step outside my area of knowledge for a 
second. Perhaps the resonant frequency of a rotary's combustion 
chamber is determined by the distance between the sideplates, as 
these are the only two parallel surfaces in it. If you can find the 
above equation, and substitute that distance into the Bore variable, 
it'd be a starting point.

0.02c is way overpriced for this.

Stuart Baly.
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Stuart Baly (s.baly at bom.gov.au)
Technical Officer
Cape Grim Baseline Air Pollution Station
'71 Datsun 510, '81 Yamaha RD350LC, '89 Kawasaki GPz900R
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