JPS6281996A - Drive control circuit for stepping motor - Google Patents

Abstract

PURPOSE:To drive a stepping motor by desired speed-to-torque characteristics by previously writing a translation table beforehand prepared analytically or experimentally to a read-only memory. CONSTITUTION:A counting section 1 counts the pulse rate of driving pulses applied to a drive circuit 5 from an upper-level device at every fixed time, and discrete values are memorized to a latch each time. On the other hand, a previously prepared translation table is written to a lead-only memory 2', and a numeric value memorized to the latch 6 is converted by the table. A numeric value obtained is converted by a D/A converter 31, and inputted to a DC/DC converter 33 through an amplifier 32, and a stepping motor 4 is excited by a DC output converted by the DC/DC converter 33.

Description

[Detailed Description of the Invention] [Summary] The number of pulses per unit time (pulse rate) of drive pulses applied to the stepping motor drive circuit is converted according to desired conversion characteristics, and the stepping motor is controlled according to the converted value. By controlling the excitation current of the motor, the desired speed vs. torque characteristics can be obtained.

[Industrial application field]

The present invention relates to a stepping motor drive control circuit.

A stepping motor can rotate a driven body at an arbitrary speed by changing the pulse rate of the applied driving pulse.1 For example, in a facsimile machine, the stepping motor is used to control the running of paper in the transmission image reading section or the reception image recording section. It is widely used to drive various parts.

At this time, it is desirable to be able to deal with noise caused by step motion at low speeds and an increase in load torque at high speeds.

[Problems to be solved by conventional technology and invention] Conventionally,
A constant excitation current was applied to the windings of the stepping motor. Therefore, when changing the pulse rate of the drive pulse over a wide range, there is a problem that vibration occurs due to excessive torque at a low pulse rate.
Furthermore, at high speeds, there is a problem of loss of synchronization due to lack of torque.

It is therefore an object of the invention to make it possible to drive with a desired speed versus torque characteristic.

The purpose is to prevent vibrations in low speed ranges and vibration adjustment in high speed ranges.

[Means for solving problems]

Figure 1 shows the principle of the present invention.

Reference numeral 1 denotes a counting unit that counts the pulse rate of drive pulses applied to the drive circuit 5 of the stepping motor (SM) 4.

2 is a conversion unit that converts the pulse rate obtained by the counting unit 1 according to predetermined conversion characteristics.

3 is the excitation current applied to the pupil line of the stepping motor■
This is a control unit that controls , using the numerical value obtained by the conversion.

[Effect]

That is, the pulse rate obtained by the counting section 1 is
The conversion is performed based on the desired conversion characteristics, and the excitation current is changed according to the obtained value, thereby obtaining the desired speed vs. torque characteristics.

〔Example〕

FIG. 2 is a block diagram of an embodiment, in which a read-only memory 2' is used as the conversion section 2.

In the figure, in addition to the same reference numerals as in FIG. 1, 6 is a launch for storing the pulse rate obtained in the counting section 1.

Note that the control unit 3 includes a DA converter (D/A) 31, an amplifier 32, and a DC converter (DC/D(:) 33).

Further, 51 and 52 represent a phase signal control circuit and a motor drive circuit, respectively, which constitute the drive circuit 5.

In the above configuration, the counter l counts the pulse rate of the drive pulse applied to the drive circuit 5 from the first-order device (not shown) at predetermined time intervals, and the count value is sent to the latch 6 each time.
is memorized.

On the other hand, a conversion table created in advance is written in the read-only memory 2', and the numerical values stored in the lunch 6 are converted using this table. The obtained value is OA converter 3
1 and then the DC converter 3 via an amplifier 32.
The stepping motor 4 is excited by the DC output input to the DC converter 33 and converted by the DC converter 33.

Therefore, by writing a conversion table created analytically or experimentally in advance into the read-only memory 2', the desired speed versus torque can be determined.

It can drive a stepping motor with its characteristics.

〔Effect of the invention〕

As explained above, according to the two aspects of the present invention, it is possible to drive the stepping motor with a desired speed vs. torque characteristic, thereby making it possible to prevent vibration in the low speed range and step-out in the high speed range.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a configuration diagram of the embodiment. In the figure. 1 is the counting section, 2 is the conversion section. 3 is a control unit, and 4 is a stepping motor.

Claims (2)

[Claims] (1). A counting section (1) that counts the number of driving pulses per unit time applied to a driving circuit of a stepping motor, and a converting section (2) that converts the count value obtained by the counting according to a predetermined conversion characteristic. , a control unit (3) that controls the excitation current applied to the winding of the stepping motor using the value obtained by the conversion;
A stepping motor drive control circuit comprising: (2). The stepping motor drive control circuit according to claim 1, characterized in that a read-only memory is used as the converter (2).