[Amps] Transformer and Inductor theory

[RFlabnotes at aol.com]

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. 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.   

Eric von Valtier K8LV