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Oscar

Newbie

Joined: 13/01/2009
Location: Australia
Posts: 2

Posted: 06:19am 13 Jan 2009

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G'day,

I'm new to home grown power but super keen to get a wind turbine up and running.
I think I have found a suitable DC motor to act as a generator but was wondering how I should go about testing it's capacity? I received it wired in three phase and needed to install 6 diodes to get any measurable voltage from it, once the diodes had been fitted I was able to get around 16 volts at around 100 rpm and more than that at higher speeds. At this point I only want to use it to charge a 12 volt system so 16 volts is fine but how do I establish the Capacity or load of the generator?
Please go easy on the tech talk and acronyms and I'll try to keep up.

sPuDd

Senior Member

Joined: 10/07/2007
Location: Australia
Posts: 251

Posted: 12:56pm 13 Jan 2009

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G'day Oscar,

you are on the right track there. If you can jerry rig the motor shaft into the chuck
of a 240V variable speed drill, then you can test the motors output under various loads
and record them. Probably need a method of measuring the RPM. Depends on what you have
laying about and your skills. If you are looking to charge 12V batteries, then the norm
is to apply the motor across a partially flat 12V battery and measure volts/amps.

Sounds like you have a stepper motor. I assume you have a multimeter, what is the resistance
across any one of the motor coils? That will give you a good idea of what the motor is capable of.

sPuDd..Edited by sPuDd 2009-01-14

It should work ...in theory

Oscar

Newbie

Joined: 13/01/2009
Location: Australia
Posts: 2

Posted: 02:17am 14 Jan 2009

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Thanks sPuDd,
I used my battery drill to wind it over and counted the rpm over a minute. Easy enough at low speed. I should be able to get access to a lathe to test it properly at varying speeds.
Yes, I do have a multimeter, when you ask me to test the resistance across one of the coils do you mean one of the individual coils of which there are 18 or across one of the three wires coming from the motor?

wind-pirate

Senior Member

Joined: 01/02/2007
Location: Canada
Posts: 101

Posted: 03:20am 14 Jan 2009

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If you got access to a lathe, that is the best.
Start with a low speed. Check the voltage. When you reach just over 12 volts, that is cut in speed. that is when you are starting to charge a 12 volt battery.
"Be sure to note this rpm" Around 100 to 200 would be nice.

Then take it up one step at a time till you get about 20 open volts.(no load) Note this rpm. 600 or less would be ideal.

Then start hooking up 12 volt light bulbs (in paralell).

Note how many bulbs that you can light with out the voltage falling below 12 volts.
EG: 5 bulbs @ 50 amps each = 250 amps output.

Note: When you increase the voltage above 20 volts, the amps will increase too....

DO NOT remove any load. if you do you will burn out the bulbs.

Take care and Be carfull. Have fun.

THE Pirate.
stealing wind & solar energy is fun

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