>The problems with the transformer debate are primarily due to an incorrectly
>applied simpification: The 'transformer rule', that the secondary voltage
>equals N times the primary voltage. It is only valid for a steady state
>periodic waveform, such as a sinewave. For transient waveforms, any analysis
>of the circuit will require consideration of the basic inductor relationship
>V=L*dI/dT, as noted by many.
Correctamundo.
>This is the basis of practically all automotive
>ignition systems. The coil is initially 'charged' up to a primary current,
>which is then interrupted, resulting in a very large dI/dT and resulting
>voltage pulse. This pulse is multiplied by N, but the actual value of
>discharge current is controlled by the spark itself.
Some ignitions use the capacitor discharge technique. The cap is charged
to c. 400v by a DC to DC switcher supply. Discharge is via an SCR.
>
have phun, Eric
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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