At 10:09 PM 4/2/97 -0800, you wrote:
>Hello Neil,
>In a message dated 97-04-02 00:14:52 EST, you write:
>
>>Gooday Chaps,
>>
>>If I may add something here, there are sources of capacitance in the
>>secondary side of the ingnition coil. Firstly, the coil itself has some
>>capacitance itself in its secondary albeit minimal. Also, the spark plug
>>provides a source of capacitance. Governered by the equation C=eA/d where
>>e(epsilon) is the relative permittivity(dielectric constant), A is the cross
>>sectional area of the spark plug, and d being the spark gap. e for air is
>>about 1, thus with a spark plug with a cross sectional area of 7mm and a
>>spark plug gap of 3mm, the resulting capacitance is about
>>2.4microfarads(relatively large).
>>
>>However, assuming a secondary inductance of around 45 milliHenries(I am
>>assuming here), the resonant frequency calculated to about 500Hz. In a
>>4-cylinder, this means at about 15,000 RPM the spark will have the most
>>energy. Any TR3 owners care to give this a try?
>>
>>Hope I haven't bored you,
>>
>>N Drake
>>Biomedical Engineer
>>Vancouver B.C.
>>
>>1959 Berkeley
>>ex-TR7.5 owner
>
>This is very interesting, and definately not boring. The pieces of this
>puzzle are starting to fit together. I have un-earthed some good
>information on automotive ignition system today that I am converting
>to an email-able form. If you are interested, I could send you a copy.
>
>
>--
>Bob Sykes - - - __,@_\____ s1500@worldnet.att.net
>'78 Spitfires - -- }-0-----0-> s1500@aol.com
>
>
Greetings
I would love a copy of these schematics. An error I just noticed is that
secondary inductance is more in the range of 45 Henries(not milli henries).
This considerably lowers resonant frequency.
Neil Drake
59 Berkeley
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