PMA drag load?

[VosaME]

So I have been wanting to go to a PMA system when my engine is back together but was wondering if it caused more (or any) of a drag load on the engine? Since the PMA has permanent magnets (obviously), and they will always induce a voltage into the stator windings when it is rotated, does that mean that it is always causing resistance to the engine turning over? Or is this taken care of in the regulator/rectifier?

I guess another way of asking this is does the PMA always produce 200w? Or is that just the max it can produce and it actually only produces the required output and the rest is dumped via the regulator...?

Thanks in advance, I could not seem to find this stated anywhere... or maybe that means it is not worth worrying about

 

[pamcopete]

VosaME,

At higher RPM's the PMA always produces its maximum power. The regulator shunts the excess power to ground and consumes it as heat.

1 Watt is equivalent to .00134 Horsepower, so a 200 Watt PMA will use 200 X .00134 =
.268 HP, so not really a factor.

 

[XSLeo]

The PMA puts out it max at all rpms. At idle the max is not much but as the rpms increase so does the output. If the PMA is putting out more than the bike requires the excess is dumped by the reg to ground through a big resistor creating heat.
In the stock system with an electromagnet in the rotor the same applies, at low rpms the output is small and increases as the rpms increase. The reg instead of just dumping the excess, the reg turns off the rotor. No magnet = no output.
The difference in engine drag between the stock and a PMA may not be much but if you have your bike running at idle and unplug the reg/rec on the stock alternator the idle speed changes. I first noticed this when trouble shooting my system, When you do the reg bypass test and this makes the alternator max out your engine idle speed drops noticably.
Will the difference be enough to notice at anything more than idle speeds?
Leo

 

[VosaME]

Thanks guys, that was just what i was wondering! Always, appreciate all the help on here!