Body
Hi Sven,
"The coil has the endeavor to change the polarity, the coil itself is a voltage source but counteracts the actual voltage source."
The coil is a current source. Coils don't like to change the current but instead changes the voltage to fit the current through it. It is exactly opposite to capacitors that don't like to change the voltage but instead changes the current to fit the voltage.
When the current is running through a coil from an external source and then shut off it tries to keep on running. Think of a spinning flywheel where the motor driving it is shut off. It tries to keep on spinning. When the circuit is disrupted the current keeps on running which changes the direction of the electromotive force (the voltage). This makes the coil change from receiving energy to giving off energy. Or the coil changes from motoring to generating. To keep say 1A running in an open circuit makes the induced (generated) voltage approach infinity if there is nothing to absorb the energy. A spark will flash over before the voltage reaches infinity as the air or whatever insulation is used can't stand an infinite high voltage. The capacitance between the windings also stores some of the energy to prevent an infinite high voltage.
For a capacitor it is the current that approaches infinity when trying to change the voltage across it by for example shorting it. Thus the capacitor behaves like a voltage source trying to prevent changing the voltage across it.
The diode is reverse biased but may break down when the voltage across it becomes big enough. Then it will behave like a solid state spark gap.
Regards
Ole
---In [email protected], <s.friedrich@...> wrote :
Hi Ole,
how should the charge in the coil banger run because of the freewheeling diode on the xenon tube.
The coil has the endeavor to change the polarity, the coil itself is a voltage source but counteracts the actual voltage source.
Something is missing at the circuit.
regards
Sven