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Old 03-01-2009, 07:45 PM
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Aaron Aaron is offline
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Join Date: Feb 2007
Location: Washington State
Posts: 10,845
The spike is NOT back emf

Back EMF "voltage" is lower than the input voltage 100% of the time. Back EMF is NOT the spike, period - it has been spelled out clearly that Back EMF is NOT the spike.

I would appreciate no more comments about calling the spike Back EMF because it is NOT WHAT THE SPIKE IS. It is misinformation plain and simple and everyone using the term back emf for the spike is simply doing so incorrectly - out of not even knowing what the difference is.

LOOK AT THE CHRONOLOGY OF EVENTS - it is common sense:

1. You charge a coil.
2. DURING the applied charge on the coil, LENZ's Law is in effect and you get BACK EMF - DURING THE APPLIED CHARGE.
3. You disconnect the power and you get the spike.

It is no more complicated than get the spike AFTER the applied power and AFTER the Back EMF have DISAPPEARED.
Aaron Murakami

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