16 analog channel oscilloscope for hobbyist?

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DMahalko

Joined Oct 5, 2008
189
I have done a lot of research on the history of how electric motor / generator technology was developed. On Wikipedia, I created the Gramme ring article, the Dynamo article, lots of historical exploration of electric power.

Generally anything that is a motor can be driven as a generator and vice versa. The main issue is how it’s commutated, and if the field is permanent, series (high voltage) or shunt (high current) wound.

The old mechanical brushed commutators were directly reversible. The modern silicon electronics are usually one way only, unless special considerations are made.

The more fancy motors and generators will advance or retard the field the faster it spins. The old fashioned way was to physically move the brushes. The modern way is to use adjustable power fixed field coils between poles called interpoles. I don’t see anything like that here.

Motors produce back-EMF which is basically it operating as a generator as it spins, which then eats some of the load current coming in.

This looks like a basic three phase alternator. It’s pretty much the same thing as a standard 50/60 Hz three phase alternator, but likely at its own weird voltage and frequency, decided by Honda engineers.

The main difficulty is the inverter. It likely reads the three phase as a tachometer to measure engine rpm, and pulls some power from it while a person is pull-starting it to energize its circuits, and move the electronic throttle to the start position.

Generators are normally supposed to be started with no load, and so once the inverter tops off its capacitors it will not draw any more power from the alternator during starting, beyond keeping its no-load sinewave active.

Speaking of which, the alternator either has residual magnetism in the iron or small permanent magnets, so it can produce some powerwhile pull-starting.

The inverter is not going to have a way to tell the difference between voltage coming into it from an alternator or voltage coming into it from an external source driving the alternator as a motor.

As long as the external power source doesn’t spin the alternator as a motor any faster than the average speed that it spins while it is being pull-started, the inverter should not be freaked out by this, and go into some weird emergency shut down mode.
 

MaxHeadRoom

Joined Jul 18, 2013
25,976
The old mechanical brushed commutators were directly reversible.
Motors produce back-EMF which is basically it operating as a generator as it spins,
And if wound field, only one or the other, armature or field, is reversed.
DC shunt wound generators will self excite, and pull them selves up, due to residual magnetism,
IOW, only rotary motion required.
 
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