Speed adjusting switch for electrical tool

Abstract

The invention relates to the technical field of electrical tools, specifically to a speed adjusting switch for the electrical tool, comprising a switch S, a rectification diode V, a resistor R, a potentiometer RP, a capacitor C, a single-phase series excited motor M and a thyristor VSCR; one end of each of the switch S and the single-phase series excited motor M is connected with a power supply voltage U, and the other end of the switch S and the single-phase series excited motor M is connected with the rectification diode V, the resistor R, the potentiometer RP, the capacitor C and the thyristor VSCR. The speed adjusting switch is simple in structure and capable of adjusting resistance of the potentiometer that is adjusting the charging and discharging time of the capacitor o as to change a conduction angle of the thyristor, so that the principle is simple and the operation is convenient.

Description

technical field [0001] The invention relates to an electric tool, in particular to a speed regulating switch for the electric tool. Background technique [0002] In the prior art, the speed of a single-phase series-excited motor is directly proportional to the voltage applied to the motor and inversely proportional to the current. Changing the voltage can change the speed. There are many ways to change the voltage. At present, the most commonly used method is to change the voltage of the thyristor. The conduction angle is used to adjust the voltage. There are many such basic lines. Various links are added to the basic lines, and there are few lines for improving or adding functions. Contents of the invention [0003] The technical problem to be solved by the present invention is: there are many basic routes for motor speed control switches, but there are few routes for improving or increasing functions by adding various links to the basic routes. speed switch. [0004] I...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, the speed of a single-phase series-excited motor is directly proportional to the voltage applied to the motor and inversely proportional to the current. Changing the voltage can change the speed. There are many ways to change the voltage. At present, the most commonly used method is to change the voltage of the thyristor. The conduction angle is used to adjust the voltage. There are many such basic lines, and various links are added to the basic lines, and there are few lines for improving or adding functions.

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