Author Topic: RPM effect on output of 3phase AC dynamo  (Read 1706 times)

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Offline newtothisTopic starter

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RPM effect on output of 3phase AC dynamo
« on: January 29, 2015, 08:43:14 pm »
Hello everybody,
Google failed me so I hope you would kindly help me.

I recently made a spontaneous bid on an low bid auction on ebay and suprisingly won a three phase AC dynamo/motor for Next to nothing.The dynamo comes with 6 diodes so a rectifier for DC can be made.  I think I will add a capacitor also to smoothe out the ripples.
The question is simply what happens at different RPMs Applied at the primary gear?

My Google was less than succesfull and the only info I could find is that lowering of RPM causes hertz to be lowered and vice versa, but how will this affect the voltage / current in the DC output - I got the impression that voltage is unaffected, but then current must be changed, I mean something has to give?
In addition the dynamo is listed as 3V-5V contradicting my earlier impression.

I would really like to know it because I want it to have a purpose and I have considered make a windmill or watermill and harness the output for something.. a small fountain, lamp.. not really sure yet - but I need to know the output first.

Link to an identical item:
(http://www.ebay.com/itm/DC-3V-5V-Hand-cranked-Dynamo-Charger-Flashlight-Generator-Brushless-Gear-Motor-/181418530418?pt=Radio_Control_Parts_Accessories&hash=item2a3d631672)

Thank you
The sad truth is that when masked by the umbrella of Anonymity the social restraints can safely be removed, and so the inner troll emerges from its cave.
 

Offline IconicPCB

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Re: RPM effect on output of 3phase AC dynamo
« Reply #1 on: January 29, 2015, 10:13:59 pm »
Both frequencyand voltage will be affected. Voltage will drop with reduction in RPM assuming no active regulator present.

If the regulator is present then the voltage versus RPM will be under the control of regulator.

 

Offline ovnr

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Re: RPM effect on output of 3phase AC dynamo
« Reply #2 on: January 29, 2015, 10:19:02 pm »
First off, that's... not really a dynamo. It's just a cheap 3-phase BLDC motor, and like almost all motors it can work as a dynamo.

The output voltage, current and frequency will change depending on RPM. It cannot be directly regulated via adjusting the field strength, like proper dynamos, so if you require a constant voltage, I suggest a buck-boost regulator on the rectified output.


Also, it's probably crap. Good luck, tho!
 


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