Electric power calculation The coil resistance of a small DC motor is 20 ohm, which is connected to a 120 V power supply. When the power intensity of the input motor is what, the maximum output power of the motor can be obtained? What is the maximum output power? It's just a common topic. Don't be too complicated

Electric power calculation The coil resistance of a small DC motor is 20 ohm, which is connected to a 120 V power supply. When the power intensity of the input motor is what, the maximum output power of the motor can be obtained? What is the maximum output power? It's just a common topic. Don't be too complicated

The output power of the motor comes from the power supply, but its size is not directly determined by the power supply
When the power supply voltage is constant, the output power of the motor mainly depends on the load. The greater the load is, the greater the current is, and the greater the output power is. The product of current and voltage is the input power of the power supply. The output power can be obtained by subtracting a certain loss. Generally, the motor has an efficiency value, and the output power can be obtained by multiplying the input power. This value is generally above 0.9
It should be pointed out that the current is not 120 / 20 = 60A, but derived from 120 = u + I * 20, where u is the back EMF of the motor armature, which depends on the load
Of course, it is impossible to be infinite. The mechanical strength of the motor determines a limit. At the same time, the wire diameter and heat dissipation conditions of the motor coil also determine a maximum current
So you check the motor name plate, there should be a rated power, that power is basically the normal maximum power. Occasionally it is possible to exceed, but it is generally not allowed, the motor will burn out for a long time