A rotating speed adjusting circuit and electric saw power supply

According to the rotating speed adjusting circuit and the electric saw power supply, the input unit, the rotating speed adjusting unit and the rectification full bridge are arranged. When the rotatingspeed of the motor needs to be adjusted; sliding resistor VR through sliding, the resistance value of the sliding resistor VR is changed; the bidirectional triode thyristor Q1 is enabled to be in a conduction, cut-off or semi-cut-off state, the magnitude of the current output to the motor by the output unit is finally changed, the rotation speed of the motor is adjusted, the electric saw is enabled to have a multi-gear function, an operator can flexibly rotate the motor according to actual needs, and maximum utilization of resources is realized. Besides, the rotating speed of the motor can beadjusted without a built-in chip, so that the manufacturing cost of the electric saw power supply is greatly reduced, and the profit of an enterprise can be increased; furthermore, a trigger diode D1is arranged, so that an ov