Methods for changing the speed of micro DC motors

The original speed of micro DC motors is generally thousands of revolutions. If the required speed is only a few dozen revolutions, we need to use a reduction gearbox to reduce the speed. Different speeds can be obtained through different reduction ratios. For example, the original speed is 1000, and the reduction ratio of the reduction gearbox is 1:100, then the speed we get is 10 revolutions. If the reduction ratio is 1:50, the speed we get is 20. Because the lower the output speed, the greater the output torque, so the torque of general micro DC motors is larger, which is suitable for smart locks, 3D pens, label printers and other products. In addition to the reduction gearbox, we can also adjust the speed through the following three methods.

1. Adjust the armature voltage

The voltage has a great influence on the operation of micro motors. The speed of micro motors can be changed by adjusting the voltage. It is a constant torque speed regulation method with fast dynamic response and suitable for a wide range of infinitely smooth speed adjustment.

2. Change electromagnetic force

The operation of the micromotor is generated by the mutual movement of the electromagnetic and the rotating shaft. When the magnetic field strength changes, the speed will change, so the speed can be changed by changing the electromagnetic force. This method can only weaken the magnetic flux of the micromotor and make the rated speed of the micromotor change upward. It belongs to constant power speed regulation and has a slow dynamic response. Although it can be steplessly smooth, the speed regulation range is small.

3. Adjust the resistor

Adjusting the resistor can directly change the current, so adjusting the resistor can directly change the speed of the motor. However, there is only a certain speed regulation, and the smoothness is poor, the mechanical characteristics are soft, and the efficiency is low. If you don't understand the characteristics of the motor, the motor will be burned directly due to excessive current.