Makings of a generator

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Hi Tony,

Depending upon whether the motor is three phase or single phase the diagram I posted is correct. A single phase motor will only have two ends to a winding whilst a three phase one will have the ends of the three windings common, unless there are six wires coming out in which case you will have to sort out which pairs are the start and finishes of each one.
 
Hi Tony,

Just stick a diode in each output lead, and connect the cathodes together you will then get a DC output between the diode cathodes and the other end of the winding.
The Alternators in a car generator is this circuit. Which maybe a Item you could use.
 
Thanks Baron I understand. I am still not sure what Bluejets is getting at.
The motor came off a 240V single phase dishwasher. However it is exactly like the diagram in #18. There are three sets of three coils. The three coils in each set are connected in series. The last coil in each set are joined to each other. The first coil in each set are connected to separate terminals. I assume its three phase or single phase depending upon whether one set of coils is connected or all three. For it's original purpose I would guess that one set could be 110V and two sets 220V I have no idea which terminals were originally used. But I would have thought that is irrelevant.
When used as a generator, will the output not vary depending upon the speed. As I said in my first post actual output is not so important. On a model, it would be nice to be able to use it for charging a battery for ignition / mobile and a few diodes. I have all options open to me and it would be nice to find out the best way ( without reconnecting each individual coil) to connect the three sets of coils to give the highest output at relatively low speed of a model engine.
 
Hi Tony,

When I first looked at the diagram on P18 I thought that it was star connected three phase, it didn't occur to me that you are right it would be 110 volts and 220 volts depending upon which wires you chose.

The highest output would be the 220 volt connection, that would also have the highest resistance. Yes the output will vary with speed of rotation.

As an aside I've just had a quick play with a washing machine pump that I've had laying around for a few years. The rotor flicks round as if it already has magnets in the rotor. I counted five definite steps. If I put an AC volt meter across the coil it jumps up to about 80 volts every time I flick it round. so you need to be aware that the voltage output might be more than you expect.
 
Hi Ignator,
Back in the 1970s I did a job where I was using old motor windings to make a solenoid switch... where a gap in the magnetic loop between input and output of a transformer made the output voltage vary ... but that aside, I was re-insulating wiring soldered joints with shellac. The lacquer used for the original winding "enamel" insulation from the old transformer.
Now Shellac is an organic lacquer, that becomes dissolved into a liquid in alcohol... So washing windings in alcohol is NOT a good idea, in case you wash away some insulation and it is then thinner than planned.... so fails at a lower voltage than the designer intended...
I suggest you test (or get a PROPER electrician to test) the insulation resistance of your windings using a 1000V Mega tester. NOT an AVO meter. It is the only (simple) way to be sure the windings will not suddenly blow-up, when HOT and a small voltage spike hits the windings.
Any electricians help me on this? - NOT my trade, just what the proper electrician told me when I was doing a job...
K2
 
Hi Ken,

Perfectly correct ! I've seen spirit washed windings arc over between turns on a transformer that I used for a 3Kv power supply I built for a high power RF amplifier. A mistake I had to quickly rectify. Strangely enough it produced a sharp clicking sound, which was how I originally discovered it.

I still have my Evershed megger !
 
Baron J,

You said you were playing with a washing machine pump. Could it be that the "...as if it has magnets" is due to magnets used to couple the motor part of the assembly to the pump part of the assembly. That is a common construction technique for fractional-horsepower pumps I have seen and worked with to isolate the electrified parts from the fluid-handling parts.

An example:

https://www.pumpproducts.com/little...MIoOW454y7iQMVXjfUAR3J6RqqEAQYCiABEgLGmvD_BwE

--ShopShoe
 
Hi ShopShoe,

Its quite possible that the impeller is magnetically coupled to the rotor ! Without actually destroying the totally sealed plastic housing I can't really tell. About the only other information I can offer is that the motor is rated at 230 volts 90 Watts. The fact that I get a voltage pulse when I flick the impeller blade round does suggest that its capable of generating an output voltage. I'll take a picture later and post it.
 

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