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Wasted spark ignition

Coil on plug style wasted spark transformers, so (beside the 2 pin power-input connection) each transformer has 2 HV connections

The transformer cores are firghtening small. We were note sure they are inductive (not CDI) operation. But they seem to work well with inductive.

Each transformer has 2 pins, that means it cannot be "active coil". So the inputs are power-inputs for sure.


Similar type with slightly shorter HV connection:

The 12V text is promising, it would not make sense for a CDI coil.

Also, the engine was running with the 2nd transformer, with shorter than 3ms dwell (2.5 ms was used ? guesstimated without measurement). But with the shorter HV connection, the spark sometimes happened at the wrong end of the sparkplug.

2.5 msec (VBatt=14V) seems to be a bit too high current: Using 3 x 0.1 Ohm 5W in parallel (as measuring resistor, in series with one coil's primary winding), at 1200 RPM

The peak current is twice as much, that is 2 * 4.87 = 9.74 A, which is a bit high (5..8A is usually best)

Marcell recommends trying 2.1 msec dwell and measuring again.