Motor controlling circuit with controllable driven voltage supply

Abstract

The H-bridge circuit consists of first and second switch unit, and first and second linear unit, and is used to impress driving current on motor. The error amplifier generates error signal that presents the difference between command current signal and driving current detected by current detection circuit. The status control circuit simultaneously controls first and second switch unit and feed back circuit. The error signal is selectively impressed on first and second linear unit to make one of them operate at linear mode and other one operate at off state in order to control driving current being in direct proportion to command current signal. The status circuit also controls braking circuit to make error signal convert to braking signal, and first and second linear unit operate at on state mode.

Description

【Technical field】 [0001] The present invention relates to a motor control circuit, in particular to a control circuit that provides a controllable driving voltage to the motor. 【Background technique】 [0002] Generally speaking, an H-bridge circuit composed of four switching transistors can be applied to provide driving voltage to motors, such as DC motors, stepping motors, and voice coil motors, etc., so as to control the rotation direction, speed, and other operating characteristics. [0003] FIG. 1 shows a circuit diagram of an H-bridge circuit 10 for driving a motor M in the prior art. Referring to FIG. 1, a motor M is coupled to a supply voltage source V via an H-bridge circuit 10 m and ground potential. Although the motor M is actually a complex system composed of many mechanical and electrical components, the driving voltage is basically applied to the coils in the motor M to generate a magnetic field. Therefore, the word "motor" in the following mainly refers to ...

AI Technical Summary

Problems solved by technology

However, the PWM technique causes the supply voltage source V m and excessive disturbance of the drive voltage applied to the motor M

For applications that require precise control of motors, prior art PWM techniques can have several undesirable effects

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