Hi... am have a 300 watt motor connected by an electric circuit as shown .. source is 220 v 50 hz... but when closing the circuit resistance (R2) burn.. this is my problem if can you help me to solve it.... thanks.
Your resistor power rating should be at least 1 watt or more, if your motor is working properly.
The normal max I-rms through the resistor should be ( 220/ 300 =) 0.73 amps
However, if your motor is NOT rotating, then there will be heavy current through R2, and it will overheat. This is very possible at startup time, so you should either remove R2, or possibly use an even higher power rating - say 5w resistor.
thanks for you interesting.. but i still suffering this problem till now although i did all your suggestions.
i ask now a bout designing a circuit can operate a 300 watt DC motor if the source is 220 v and overlooking the above circuit..
if you want help me.. plz
notice: the resistance of motor's coil is between 30 - 150 ohm
I would check the diode bridge, its likely that one diode has gone short circuit. there should be a small capacitor across the diode bridge or motor, say 47 NF@ 350V, to protect the bridge against sparking from the motors brushes.
Frank
motor power is 300 watt, voltage is 200 v DC, and the current is 1.5 am.
when i putting ohmmeter on the ends of motor's coil the ohmmeter reading between 30 - 150 ohm every one i rotating motor by my hand
The motor is generating juice when you rotate it. This will throw off the ohm reading.
Leave the motor stationary when checking its ohm reading. This will let you calculate the maximum amperes that must be carried. You'll have an idea what should be the ratings of the components.