JPH02159997A - Stepping motor control circuit - Google Patents

Abstract

PURPOSE:To facilitate switching between an m-phase excitation system and an (m-1)=m phase excitation system by a method wherein a code converter which converters the output of an n-bit counter, driver which supplies power to the required phase of a stepping motor in accordance with the output of a decoder and so forth are provided. CONSTITUTION:A clock input is counted by an n-bit counter 1, the output of the counter 1 is converted by a code converter 2 in accordance with at least one external control signal, a required pattern is generated from the output of the code converter 2 by a decoder 3 of the next stage and power is supplied to the required phase of a stepping motor through a driver 4 to control the stepping motor. With this constitution, if a low speed smooth rotation is required, an (m-1)=m phase excitation system is employed and, if a high speed rotation is required, an m-phase excitation system is employed and both the systems can be switched to each other easily by an external control signal.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to industrial equipment, office automation, etc.
This invention relates to a control circuit for a stepping motor used in equipment, etc.

2. Description of the Related Art In conventional stepping motor control circuits, a method is often used in which a stepping motor is driven using a circuit configuration compatible with only one predetermined excitation method.

For example, as shown in FIG. 2, a clock deviation 26 is counted by a counter circuit 21, and a predetermined pattern is generated by a multiple phase decoding circuit 22 based on the output of this counter circuit 21. In this method, the stepping motor drive output 24 is outputted via the drive circuit '#1r23 in accordance with the output of the stepping motor. 26 indicates a counter control signal. here.

The multi-phase decoding circuit 22 is a dedicated circuit compatible with the l-phase excitation method ((m-1)-in the case of the multi-phase excitation method, a corresponding (Otori-1)-multiple phase decoding circuit is required). Become.

Problems to be Solved by the Invention In the case of such a conventional circuit configuration, since the excitation method of the stepping motor is limited to one predetermined method, there are the following problems. In the case of an l-phase excitation type circuit configuration, the output torque of the stepping motor is large and high-speed rotation is possible, but torque unevenness is large and smooth rotation is difficult. Moreover, in order to suppress the torque unevenness, the structure of one mechanism has to be complicated. On the other hand, (+a-
1) In the case of the -m-phase excitation type circuit configuration, the rotation angle per step is small and there is little disturbance, but the response speed is slow and it is not suitable for high-speed rotation. Furthermore, if the circuit configuration is such that the m-phase excitation method and (11-1)-wll phase excitation method described above can be switched, a dedicated decoding circuit corresponding to each excitation method and its decoding circuit can be switched. Since a rounding switching circuit is required, the scale of the two circuits increases, leading to problems such as increased costs.

The present invention has been made in view of this point, and provides flexible stepping motor control by switching the m-phase excitation method to the (m-1)-m-phase excitation method with a simple circuit configuration. The purpose of this invention is to provide a stepping motor control circuit that enables the following.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a link input fn
The bit counter circuit counts, the output is converted by a code conversion circuit based on at least one external control signal, and the next stage decoding circuit generates a predetermined pattern from the output of this code conversion circuit, and the drive The stepping motor is controlled by supplying power to each predetermined phase of the stepping motor via a circuit.

Function The present invention is as described above! The output of the n-bit counter circuit is converted based on at least one or more external control signals by a code conversion circuit having a circuit 1C that changes the output of at least one bit of the n-bit counter circuit to a zero level or low level by the configuration. Therefore, with the same circuit configuration, m-phase excitation method and (+a-1)-
An m-phase excitation method can be realized. Moreover, it is possible to switch between the m-phase excitation method and the (ta-1)-m-phase excitation method using at least one external control signal.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In FIG. 1, 1 is an n-bit counter circuit that counts a clock signal 6 from a clock input terminal according to a counter control signal 8, and the output from this n-bit counter circuit 1 is input to a code conversion circuit 2. . The code conversion circuit 2 converts the output data from the n-bit counter circuit 1 into a predetermined code based on at least one external control signal 7.

3 is a decoding circuit which decodes the coded output from the code conversion circuit 2 and generates a desired output pattern. A drive circuit 4 outputs a stepping motor drive output 6 according to the output of the decoding circuit 3, and supplies power to each predetermined phase of the stepping motor.

According to the stepping motor control circuit configured in this way, according to the counter control signal 8, the clock from the a-clock input terminal is externally controlled by the code conversion circuit 2 to control the output of the n-pit counter 1 which counts number 6. By performing code conversion based on the signal 7 to make at least one pit of the output high level or low level, a desired output pattern can be generated by the next stage decoding circuit 3. By encoding the output of the n-bit counter circuit 2 with the code conversion circuit 2, a code for the 11-phase excitation system or the (m-1)-m phase excitation system can be easily obtained. This allows m-phase excitation and (+a-1)- with the same circuit configuration.
A one-phase excitation system can be realized.

The same effect can be obtained even if an up-counter circuit, a down-counter circuit, or an up-down counter circuit is used as the n-bit counter circuit 1.

Effects of the Invention As described above, the present invention uses the (m-1)-m phase excitation method when low-speed and smooth rotation is required using an external control signal, and the m-phase excitation method when high-speed rotation is required. This has the effect that it is possible to easily switch to the phase excitation method.

It also has the effect of reducing the burden on the software of the computer (typically a microcomputer) that controls the stepping motor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a stepping motor control circuit according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional stepping motor control circuit. 1...N-bit 2-bit counter circuit, 2...
・Code conversion circuit, 3... Decoding circuit, 4.
...Drive circuit.

Claims (1)

[Claims] an n-bit counter circuit that counts a clock having a predetermined frequency; a code conversion circuit that converts the output of the n-bit counter circuit based on at least one external control signal; A stepping motor control circuit comprising: a decoding circuit that generates a pattern; and a drive circuit that supplies power to a predetermined phase of a stepping motor according to the output of the decoding circuit.