Originally posted by mbrownn
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do it and upload the video. And I won't say for sure that is what is happening
but that's what it looks like to me. It's too difficult to explain well, but what I
see is if I adjust the input so that the input is broken by a pulse for the
collection of the field collapse, I see the recovery cap voltage climb, but
when I increase the speed/input voltage the recovery cap voltage drops.
I can't recall exactly what happened when I loaded the rotor, I'll see.
I noticed because the motor likes to use about 1 amp that if I put a 21 watt
12 v bulb in series with the field coils and power that in parallel with the
armature then the armature only uses about another 500 mA, which is almost
the same total field/armature input as idling on 12 volts with no load and
speed/power is comparable. So that makes sense to me.
I think to pulse a universal motor efficiently the field would need to be pulsed in
parallel with the armature but the field pulse should start earlier so that the
field is magnetized before the armature is pulsed. I found low frequency to be
effective when pulsing both in a series arrangement 12 Hz I am using.
The different pulse times, recovery and the overall control can be made fairly
easy and changeable by the use of a micro processor controller. But that
approach is not for everybody, there are other ways as well.
Cheers
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