dc voltage supply for small dc shunt motor

Discussion in 'The Projects Forum' started by richard295, Mar 24, 2006.

  1. richard295

    Thread Starter New Member

    Mar 24, 2006
    Trying to build field voltage source for 115 volt dc. Motor is only 1/50 hp shunt.
    Armature current is .33A. Don't know what field current is.
    From 120v ac source, connecting a bridge rectifier and smoothing capacitor of 1000uf. I think dc voltage would be 1.414 X AC source voltage? If so, I would need to decrease the voltage in this circuit to the field by about 52 volts.
    I don't know what the resistance of the field winding is and need to determine that.
    I was then going to pick a resistor or rheostat and put it in series with the field . . . picking the resistor for a 50 v drop. If I used a rheostat, I could adjust the voltage to the field.
    I don't need any motor field protection.
    I have not done anything like this before and am wondering if I'm on the right track. Any advice would be very welcomed.