current control device

Abstract

The invention provides a current control device capable of fault detection that does not need a motor speed sensor and has a wide range of applications. The semiconductor element (1) for current control has on the same semiconductor chip: a transistor (4) to drive the load, a current detection circuit (7) to detect the current of the load, and a calculation based on the current indication value and the current value output by the current detection circuit A compensator (8) for an on-duty ratio of the transistor, and a PWM timer (12) for generating a pulse for turning on the transistor based on the on-duty ratio. The microcontroller (6) sends a current command value to the semiconductor element (1) for current control, and receives the current value output by the current detection circuit (7) and the current value output by the compensator (8) from the semiconductor element (1) for current control. The on-duty ratio is turned on, and a failure of the current control semiconductor element (1) is detected based on the received current value and the on-duty ratio.

Description

technical field [0001] The invention relates to a current control device, in particular to a current control device suitable for fault diagnosis of a current detection circuit. Background technique [0002] Electric actuators such as electric motors and solenoids are widely used in order to convert electrical signals into mechanical motion or hydraulic pressure along with electronic control of various control objects. On the other hand, when an electric actuator is used for life-critical control of an automobile or the like, high reliability is required for the electric actuator. [0003] In order to improve the reliability of the electric actuator, it is necessary to reliably detect the failure of the current control device used in the electric actuator, and to stop (failstop, failure stop) the faulty current control device according to the type of the fault, so as to A function that prevents the upper system from becoming an unsafe state; or a function that avoids the fau...

AI Technical Summary

Problems solved by technology

In addition, in the case of a solenoid control device, a motor rotational speed sensor is not provided.

[0011] Therefore, in the configuration that requires the motor rotational speed sensor as in Patent Document 1, there is a problem that failure of the current detection circuit cannot be detected.

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