Matching to the impedance of an alternator.

voltage.

Frequently referred to as constant V/Hz in the AC motor speed control world. Applicable to some generators, transducers, most transformers, etc.

I'm betting that you mean maximum power. Torque is a function of current.

Well, keep it to yourself. We'll take your word for it.

John

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Hot air. You have posted nothing of substance so far except your usual claims that you know stuff you won't reveal.

I just gave you the model, and solved your "puzzle", that you didn't understand. You claim to have designed alternator regulators, and you clearly have forgotten how they work. Maybe you got the requirements from someone who did understand.

John

voltage.

I meant torque. At a given speed, current is high at short but torque isn't. Without copper and such losses, torque would be zero with a short.

At a given speed, torque tracks power, actually the sum of load power and any internal losses. Conservation of Energy demands that.

John

"Ian Field = Fuckhead "

It has the info you asked for.

Fuckhead.

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Torque is not energy; it is force. Work (energy) is force dot distance or, in this case, torque dot angular rotation.

For example, in the case of driving motors, maximum torque is developed (even at no rotation) by maximum current. That's why motors can develop starting torque when the rotation is zero (zero work).

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Of course, if you burn enough oil (or rather more natural gas) you will increase the greenhouse effect on the planet that you are inhabiting to the point where it gets uncomfortably warm, you've got to move a few miles inland, and none of the crops that you used to grow will do well in the local agricultural areas

The universe isn't reliably or persistently benevolent, and it's good idea to appreciate the limits of its benevolence.

-- Bill Sloman, Nijmegen

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I won't be keeping it to myself. I'll be posting a solution, if there is one... right now I'm trying to make sense of what a switcher load does to such an animal. It almost seems like that you'd be getting something for nothing... defying conservation of energy. I suspect it buys you nothing. ...Jim Thompson

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You gave no model, you "gave" what we already knew... observed behavior... without numerics... as usual. That's doesn't make for a model, though I do have one now.

John, Keep it up and I forget that I'm a gentleman and a scholar ;-) ...Jim Thompson

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Bwahahahahaha! ...Jim Thompson

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More rain, warmer weather, longer growing seasons, more CO2, fertilizers and energy for plowing and processing and storage and transport... will all make great crops and lift billions of people from miserable poverty and malnutrition. What's not to like about that?

Looks pretty good to me so far.

John

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Still don't get it, do you?

John

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You're an asshole and a hack. We all know that.

John

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Of course torque is not energy. But torque times angular *velocity* is power. Steady-state, energy is conserved so power is conserved.

If a shorted alternator delivers no power into a load (which it can't) and you spin the shaft and saw any non-trivial torque load, there would be mechanical power going into the shaft but no electrical power coming out. That violates COE.

It's common in aircraft power systems and on motorcycles to regulate PM alternator output by *shorting* the output. Why would they do that if it produced a big torque load on the engine? And where would all that horsepower be disappearing to?

Some motors. The equivalent to a PM alternator is a pure PM synchronous motor; in fact they are the same thing. Without some sort of assist, they won't start.

John

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I suppose MIT doesn't teach peeping toms about conservation of energy, either.

John

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Yes, I do understand it... but you don't ;-)

You've already made an ass of yourself in this thread, but all the viewers are ignorami, and don't know it... a sad state for our country :-( ...Jim Thompson

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I'm definitely an asshole... I'm going to annoy you forever. You, on the other hand are a dunce.

Hack? Nope. Want to count working circuit designs... and patents ?:-) ...Jim Thompson

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It means that the load is much lower in impedance than the internal impedance of the alternator. Or equivalently, that the alternator terminal voltage is much lower than its open-circuit voltage would be. That's the way most PM alternators work once they're in their operating speed range. Both JT and Ian have noted that an alternator which is intended to drive a low-voltage load will give you a healthy shock open-circuit.

Y axis is alternator current into a low-impedance load. X axis is shaft speed. It starts at 0,0, ramps up sort of linearly, then flattens out. The initial ramp region is where the resistive losses in the coils and the load dominate. Once the frequency gets high enough that the alternator coil inductance dominates the total impedance, the curve gets pretty flat. Visualize that if you can; if not, draw it. It looks just like a single-pole RC highpass filter.

It's hopeless to explain things to people who are pre-determined to reject understanding them.

John