Please help clarify a few things

[Baling Wire]

after researching the board; I still have NO clear answers to 2-3 questions in my mind.  I think that I know the answer to #1.  Does Jerry-connected-parallel and delta give the same open circuit dc voltage for the same rpm?  #2.  If so?, which or will both? deliver the most/same? amps at a given rpm into a battery of given voltage?  i.e. comparing apples and apples.  #3.  If the effective internal resistance of star and delta are the same; then how does jerry-connected-parallel fit it?

I have an ECM, star connected, when rectified calculates to give an o. c. voltage

of 12.3 at 75 rpms.  The dc line resistance for 2 phases measures 6.7 ohms.  Using a prime mover (1/2 drill) when connected across a 4.3 ohm load, it will cause a 14 volt drop giving a calculated 3.25 amps.  By my figures thats 45.6 watts.  The drill didn't appear to drop too many rpms in this test.  But, when connected across a 12.67v battery the delivered current was only 1.3 amps; the drill was heavily loaded and the coupling was doing some slipping??  I think maybe the cutin rpms needs to be raised and hopefully in the process improve the efficiency and overall output.

I have been led from reading the board that this ECM should deliver 300-330 watts.  I'm skeptical,  I think 150 watts or less is more in the ball park for this motor

in a 25 mph wind.

I'm open for suggestions as to the best way to set it up?

BW  

[ghurd]

The star cut in is too low.  It is better to Jerry rig it.  The volts/RPM and the resistance both go down, then the charging amps and efficiency go up.

The 300~400W is for 1 HP with the wiring reconfigured.

Smaller ECMs make less power.  

The 1/2HP makes about 150W max by Jerry's figures, in the link.

http://www.fieldlines.com/story/2005/4/16/42254/0713

G-

[Flux]

That is a high voltage motor with a high internal resistance. If you want to get anything out at 12v you need to connect it for a higher cut in speed and lower internal resistance.

Connecting delta will reduce the internal resistance to 1/3 of the star value and will help a lot. Jerry connection will have a similar effect and may do a bit better, that is probably your best option.

Don't expect miracles from something designed for an entirely different purpose. 2 ohms is still a high internal resistance for a 12v generator. What you can screw out depends on the wind and how much you are prepared to overload it. 300W in delta/jerry may be possible, it's not really suitable for star at 12v.

Much more suited to 120v hydro, but it will do something at 12v.

Flux

[cardamon]

Just a sec...What is jerry connected? I have not heard that term before.  Searched but could not find an explaination.  Thanks.

[ghurd]

It is a way to connect a 3 phase alternator, that didn't have a name.

Jerry thought it up or at least did a lot of testing, so Jerry Rigged.

Each phase is rectified separately.  The outputs are paralleled to the battery.

It is a good option for some alternators, if a rewind is to be avoided.

It is similar to Delta in some respects, though I always get better results from Jerry Rigged.

G-

[wooferhound]

Jerry Rigged is the term

Here it is . . .

[Flux]

Woof

That is the series connection that may help when the cut in speed is too high. In this case the opposite is required. The 3 single phase bridges need connecting in parallel, not series as shown. Join the bridge positive outputs to battery positive and bridge negatives to battery negative. Capacitors are not needed for the parallel connection.

Flux