What is the principle of stepless speed regulation for electric drills? Is the speed change achieved by pressing the button?
Otherwise, the motor speed is smaller. What's more, the speed change is to change the average current power on the load from the 0-100% by changing the duty ratio of the output square wave, thus changing the load, that is, the speed of the motor.
When the potentiometer is adjusted, the smaller the effective resistance is, the greater the current is to drive the SCR. The thyristor is easy to drive, and the less the current is cut off, the greater the speed of the motor.
The principle is the use of silicon controlled variable voltage transmission.
