Current detecting circuit for overload protection and overcurrent protection of brushless direct current motor

Abstract

The invention relates to a current detecting circuit for overload protection and overcurrent protection of a brushless direct current motor. The current detecting circuit for the overload protection and the overcurrent protection of the brushless direct current motor comprises a single-chip microcomputer, a current sampling circuit and a power module, and the current sampling circuit is connected with the single-chip microcomputer and the power module respectively. The current detecting circuit for the overload protection and the overcurrent protection of the brushless direct current motor has the advantages that the influences of magnetic core saturation brought by a current transformer are avoided, the current detection precision is high, the circuit structure is simple, cost is low, and the current detecting circuit for the overload protection and the overcurrent protection of the brushless direct current motor is easy to implement and can achieve the overload protection and the overcurrent protection of the brushless direct current motor.

Description

technical field [0001] The invention relates to a current detection circuit for overload protection and overcurrent protection of a brushless direct current motor. Background technique [0002] In the electric actuator, the torque limiting mechanism is used to cut off the motor control circuit when the load torque is too large, so that the motor stops until the fault is eliminated, so as to avoid overload, so as to ensure the integrity of the physical structure of the motor and the safety of the operator. The electronic torque detection method can obtain a more accurate torque value through calculation, so in some occasions it has replaced the mechanical torque limiting mechanism that can only qualitatively reflect the magnitude of the torque, and has become a common method for torque detection. [0003] According to the basic theory of the motor, its torque value can be obtained by calculating the motor current, speed, etc., and the speed is relatively easy to observe. Ther...

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Problems solved by technology

[0004] At present, the commonly used current detection circuit mostly uses the current transformer as the core; however, the accuracy of this method is not good, and the magnetic core of the transformer may be saturated, which affects the control accuracy to a certain extent, and is not suitable for long-term use in current detection. Where higher precision is required

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