JPS63249498A - Control circuit for stepping motor - Google Patents

Abstract

PURPOSE:To always generate a constant motor torque by correcting a pre- connection phase switching timing on the basis of detection speed data, and then generating a switching timing. CONSTITUTION:A comparator 2 compares a detection speed obtained by a motor speed detector 1 with a set speed and generates a motor phase switching timing synchronously with a rotary encoder signal. A corrector 3 calculates a correcting time from a motor phase switching timing (pre-connection switching timing) obtained from the comparator 2 and a motor detection speed to generate a motor phase optimum switching timing (post-connection switching timing). A motor phase switching controller 4 drives a motor phase at the switching timing generated from the corrector 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a step motor control circuit, and particularly to a step motor control circuit equipped with a rotary sensor.

[Conventional technology]

Conventionally, this type of step motor control circuit mounted on the rotary sensor 1 has been designed to detect the motor position angle from the rotary sensor and draw out the maximum torque of the motor, thereby shortening start-up and fall time and distance.

[Problem that the invention seeks to solve]

However, the conventional control circuit for a step motor equipped with a rotary sensor described above can only change the phase at a certain motor angle due to the accuracy of the rotary sensor. It had the disadvantage of large fluctuations. Also, by changing the motor position angle detected by the rotary sensor and switching the phase of the step motor, it is possible to keep the speed to a certain level, but on the other hand, the disassembly accuracy of the rotary sensor,
Since the deviation of the moke position angle caused by the detection processing time differs depending on the speed, there is a drawback that a predetermined torque cannot be generated and speed fluctuations become large.

[Purpose of the invention]

The present invention improves the drawbacks of the conventional example, and provides a step motor control jff11 circuit that allows phase switching to be performed at any motor position angle and that also minimizes speed fluctuations of the step motor. If you provide
That purpose.

[Means for solving problems]

Therefore, in the present invention, a speed detection circuit inputs a signal from a rotary sensor and outputs a corresponding speed signal, and compares output data of this speed detection circuit with predetermined set speed data to obtain a predetermined speed signal. The motor phase switching control circuit includes a comparison circuit that outputs motor phase switching timing, and a motor phase switching control circuit that is energized by the output of the comparison circuit to switch and drive the motor phase. Furthermore, a correction circuit is installed between the comparison circuit and the motor phase switching control circuit, which calculates a correction time based on the output of the comparison circuit and the output of the speed detection circuit, and outputs the optimum motor phase switching timing. The structure is adopted.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In this embodiment of FIG. 1, the signal A from the rotary sensor is
A speed detection circuit 1 inputs and outputs a corresponding speed signal, and compares the output data of this speed detection circuit 1 with set speed data B set separately in advance to determine a predetermined motor phase switching timing. The motor phase switching control circuit 4 includes a comparison circuit 2 that outputs an output, and a motor phase switching control circuit 4 that is energized by the output of the comparison circuit 2 and switches and drives the motor phase.

A correction circuit 3 is provided between the comparison circuit 2 and the motor phase switching control circuit 4, and the correction circuit 3 calculates a correction time based on the output of the comparison circuit 2 and the output of the speed detection circuit 1, and outputs the optimum motor phase switching timing. ing.

The motor speed detection circuit 1 has a function of detecting speed from a rotary encoder signal. Comparison circuit 2 compares the detected speed obtained by motor speed detection circuit 1 with a set speed, and generates motor phase switching timing in synchronization with the rotary encoder signal. The correction circuit 3 obtains 4 from the comparison circuit 2.
Calculate the correction time from the corrected motor phase switching timing (switching timing before correction) and motor detection speed, and calculate the optimal motor phase switching timing (switching timing after correction).
will occur. The motor phase switching control circuit 4 drives the motor phase at the switching timing generated by the correction circuit 3.

Therefore, as shown in the timing chart in Figure 2, by generating the post-correction switching timing based on the detected speed data from the pre-correction switching timing, it is possible to always generate a constant motor torque. .

〔Effect of the invention〕

As described above, according to the present invention, the motor position angle obtained from the rotary sensor, the detected speed obtained from the speed detection circuit, and the correction circuit are used to maintain a constant speed at an arbitrary set speed and with minimum speed fluctuation. It is possible to provide an unprecedented and excellent control circuit for a step motor that can perform phase switching at the same time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation of FIG. 1. ■... Speed detection circuit, 2... Comparison circuit, 3... Correction circuit, 4... Motor phase switching control circuit. Patent applicant: NEC Co., Ltd.

Claims (1)

[Claims] (1). A speed detection circuit inputs a signal from a rotary sensor and outputs a corresponding speed signal, and compares the output data of this speed detection circuit with predetermined set speed data to determine a predetermined motor phase switching timing. In a step motor control circuit comprising a comparison circuit that outputs an output, and a motor phase switching control circuit that is energized by the output of the comparison circuit to switch and drive the motor phase, A control circuit for a step motor, characterized in that it is equipped with a correction circuit that calculates a correction time based on the output of the comparison circuit and the output of the speed detection circuit and outputs the optimum motor phase change timing.