Author Topic: Over 80% Efficiency  (Read 798 times)

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WXYZCIENCE

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Over 80% Efficiency
« on: March 06, 2007, 08:20:54 AM »
I mounted this 1hp dc motor to the work bench and added a belt system, speed controller and test meters for a range of efficiency tests.







The frequency meter reading is divided by 3 because of the three pole magnet passing the pickup. My tests ranged from 100 hz to 400 hz. , two loads 60 watt and 160 watt. I also did an open circuit voltage test. The temperature of the coil was also monitored.







Here for an example the frequency reads 323. I divide the reading by 3 = 107.66 Hz times 60 = ~6459 rpm. The load was a 60 watt bulb. E x I = 46.88 watts. The open circuit volts at the same rpm was 8.25. With 160 watt bulb the Voltage 7.15 and the current was 10.1 amps, or 72.21 watts. The voltage drop was just over 1 volt with either load.


Note#1: The head was tested to 15000 rpm for 2 minutes then examined. After inspection there was found small cracks in the epoxy. I believe that the epoxy had contracted overnight and with the over speed test caused small cracks. The epoxy was removed and replaced with a more flexible silicone rubber. I will take more tests to the maximum designed speed of 12000 rpm tomorrow.


Note#2: The temperature was monitored by a sensor attached directly to the coil. Through all of the tests (which lasted for more than an hour) the temperature of the coil did not exceed 27 degrees C.
Joseph.
« Last Edit: March 06, 2007, 08:20:54 AM by (unknown) »

willib

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Re: Over 80% Efficiency
« Reply #1 on: March 07, 2007, 09:09:48 PM »
did you use a Couple of Fets for the speed controller ?

sony beta , hmmm , that would make an excellent hub for a minigen , i'm gonna have to keep an eye out for one , come spring when garage sales get going
« Last Edit: March 07, 2007, 09:09:48 PM by willib »
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