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Topic: Eumig 810/824 motor amp?
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Martin Jones
Phenomenal Film Handler
Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008
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posted January 29, 2009 08:44 AM
Measurements taken on the motor of an 824 while running give the following results;-
Voltage across motor = 220 VAC Motor current = 0.46 A
I don't know whether one can control the speed of this particular motor by reducing the voltage with a resistor in series, but trying it should not harm the motor. To reduce the voltage by 10%, 50 ohms should be placed in series with one of the motor leads (Blue/Yellow on my machine). Best would be a rheostat of about 120 ohms maximum and of 25 watts minimum rating. Connect in series, with the rheostat set to zero ohms, switch on (CAREFUL.... THE RHEOSTAT ELEMENT IS AT MAINS VOLTAGE!) and increase the resistance gradually. Any change of speed should be audible. Set the rheostat to give the lowest speed you require; if the rheostat is too hot use one of a higher wattage rating. If the speed does change significantly, but you cannot get a low enough speed you need more resistance (and a higher wattage rated rheosat).
BUT, if there is no speed change, or very small, then the motor is probably an induction motor and you will need a thyristor motor speed change circuit(not my expertise). Someone else on the Forum may be able to help; it must be capable of feeding a 220volt 150 watt motor. Also the 375w controller on this page....
http://www.quasarelectronics.com/cr0008.htm
seems to be suitable (the link to the user manual .PDF is incorrect).
Email me if I can help further. Martin [ January 29, 2009, 12:39 PM: Message edited by: Martin Jones ]
-------------------- Retired TV Service Engineer Ongoing interest in Telecine....
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