What is the volt and amperage of a typical lawnmower plug?


lawnmower
Jed S asked:


I would like to know how much juice is provided by the lawnmower’s magneto to the coil to the plug wire, could that power an electromagnet?

This entry was posted on Thursday, January 22nd, 2009 at 12:00 am and is filed under Engineering. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

2 Responses to “What is the volt and amperage of a typical lawnmower plug?”

  1. billrussell42 Says:

    This is, I think, high voltage pulses, with a rep rate tied to the engine’s rotation speed. Be difficult to design a transfromer to run from these conditions. Specially if the engine speed is changing.

    Actually, probably not possible…

  2. Numbat Says:

    Very rare to have a magneto in modern small engines. Usually, the electrics use a CDI system where two coils are held near the flywheel which has a magnet embedded in it. The first coil is used to charge a capacitor and the second coil is used to trigger a SCR to rapidly discharge the capacitor through a coil/transformer. It is the rapid discharge that creates the spark. Unlike a magneto, no points are involved.

    Intrinsic Voltage produced by the CDI system is somewhat variable since it depends on the capacitor charge which varies with engine RPM. However the actual voltage is set by the gap of the spark plug since the voltage can not rise higher than the arc-over point.

    The current is very small (and the voltage is high which will give problems with insulation). It would not be practical to power an electromagnet.

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