Starting-Rheostat
EEE
A Starting Rheostat is a variable resistor used to limit the starting current in electrical machines, especially DC motors. When a motor starts, it draws a very high current because there is no back EMF at that moment. To protect the motor from this excessive current, a starting rheostat is connected in series with the armature circuit.
At the beginning, the rheostat provides maximum resistance, reducing the current to a safe level. As the motor speeds up and back EMF builds up, the resistance is gradually decreased. Once the motor reaches its normal speed, the rheostat is completely removed from the circuit.
Thus, a Starting Rheostat ensures smooth acceleration, prevents damage, and protects the motor during startup.
Tags: A Starting Rheostat is a variable resistor used to limit the high starting current of a motor and ensure a smooth, safe start.