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Waervyn
Aug-02-2014, 10:53
So...I've been reading about magneto's, as I had no idea what they were.
One thing still eludes me though. If the magneto creates a spark for the engine...and the magneto works with magnets. What provides the energy for the magnets to start doing their job? I mean...it's not a 'Perpetuum mobile', so something must drive it...but the only thing we do in the plane is flick a switch. Is there some electrical current that gets it going?

III./ZG76_Saipan
Aug-02-2014, 11:05
i think thats why you hand crank it or use a small explosive charge like in the corsair.

ATAG_Snapper
Aug-02-2014, 11:08
It's the turning of the engine itself that generates the electrical current to provide spark to the spark plugs. A starter motor is used to get the engine turning in the first place in the MK 1 Spitfires and Hurricanes (supplied by an external power source by the ground crew). The Spitfire 2a had an explosive cartridge to turn the engine over on start up. Once the engine is turning an electrical coil/stator provides the electrical power. I think. Or it's magic. :D

Baffin
Aug-02-2014, 11:15
So...I've been reading about magneto's, as I had no idea what they were.
One thing still eludes me though. If the magneto creates a spark for the engine...and the magneto works with magnets. What provides the energy for the magnets to start doing their job? I mean...it's not a 'Perpetuum mobile', so something must drive it...but the only thing we do in the plane is flick a switch. Is there some electrical current that gets it going?

Check this out:

http://science.howstuffworks.com/question375.htm

Waervyn
Aug-02-2014, 11:24
Check this out:

http://science.howstuffworks.com/question375.htm

Thanks for the link, much appreciated! The thing is though, with a lawnmower or chainsaw you have to pull really hard on this chord (I guess to get the magneto spinning?)
In the airplane, we just flick a switch. But if in real life first some crank has to be twisted it makes sense. However, if it's really only flicking the switch it still doesn't make sense (to me ^^ )

Thanks again!

Artist
Aug-02-2014, 11:30
Concerning the Spits, see the bugtracker, too: http://tfbt.nuvturais.de/issues/479

Clipper79
Aug-02-2014, 15:50
magneto's are spring loaded at low rpm..thats why you hear the click click click until rpms increase.

been a long time but thats what I remember.

S!

jmack
Aug-03-2014, 17:29
Moving a magneto switch to 'ON' permits the electrical charge generated by the magneto to be received by the spark plugs. As long as the engine rotates the magnetos generate electrical power. If a magneto was 'hot' wired, the engine could
start by someone accidentally turning the propeller.