Electric Actuator Motor Overload Protection Circuit

Abstract

The invention discloses a motor overloading protection circuit for an electric actuator, and the circuit comprises a control circuit, a forwarding branch circuit, a reverse branch circuit, and a common branch circuit. The control circuit comprises a first normally opened relay, a second normally opened relay, a temperature switch, and a conversion type relay input part. The input part of the first normally opened relay is connected with a forwarding control end and a common control end. The input part of the second normally opened relay is connected with a reverse control end and the common control end. The output parts of the first and second normally opened relays are connected in series between the forwarding control end and the reverse control end. The temperature switch is in series connection with the conversion type relay input part, and the other end of the temperature is connected with the common control end. The other end of the conversion type relay input part is connected between the output parts of the first and second normally opened relays. The protection circuit employs the temperature switch for detection, is simple in installation, is simple in debugging, is low in cost, and is high in reliability.

Description

Technical field: [0001] The invention relates to the technical field of electric actuator motor overload protection, in particular to an electric actuator motor overload protection circuit. Background technique: [0002] More and more factories adopt automatic control, manual operation is replaced by machinery or automatic equipment, and the actuator plays the role of the interface between the control system and the valve mechanical movement; in some dangerous occasions, the automated actuator device can Reduce personnel injuries; some special valves require emergency opening or closing under special circumstances. The valve actuator can prevent the danger from spreading further while minimizing plant losses. [0003] Actuators are divided into pneumatic, electric and hydraulic actuators according to the driving energy used. Among them, the main advantages of electric actuators are high stability and constant thrust that users can apply. The maximum thrust generated by the actuato...

AI Technical Summary

Problems solved by technology

[0004] At present, the overload protection of switch-type electric actuators is detected by mechanical devices, and then the travel switch is used to disconnect the power supply, thereby preventing the motor from being overloaded for a long time. However, due to the complexity of the mechanical devices and the resulting high cost , can not be used in some low-cost electric actuators, such as the patent with the notification number CN203906956U, which realizes overload protection through torque switches coupled with sampling and screening circuits; the other relies on sensors to detect the current of the motor, through circuit to calculate and judge whether it is overloaded, this circuit also has the disadvantages of complicated circuit debugging and high cost, such as the patent of CN2570835Y, which includes a microprocessor CPU, a position sensor

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