JPS58136296A - Drive control circuit for pulse motor - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a pulse motor during the stopping period by opening or closing the signal of a monostable multivibrator which is started by a reference signal, thereby switching a power source voltage of a decoder which converts the code of the output of a counter. CONSTITUTION:A reference signal CK1 is inputted to a counter 61, supplied to a monostable multivibrator having NAND gates 84, 85 a transistor 88 is switched by the output of the mutivibrator, the power source voltage of high level is applied to a decoder 65 which converts the output signal of the counter 61 to a code at the ON time and the power source voltage of low level is applied to the decoder 65 at the OFF time. The signals of the decoder 65 are applied to operational amplifier 82, 83 to obtain outputs X, Y, and drive voltage to each phase of the pulse motor is prepared by switching the outputs by a switch. Accordingly, the drive voltage can be reduced during the stop period after the positioning operation is completed, thereby reducing the power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control circuit for a pulse motor, and its purpose is to control the drive output voltage during the stop period of the pulse motor to decrease compared to the drive output voltage at the end of rotation. Another object of the present invention is to provide a pulse motor drive control circuit that saves power consumption during the period when the pulse motor is stopped.

Conventionally, pulse motors, which input pulses as reference signals, have been widely used in drive units of devices that require accurate positioning of movable objects at predetermined locations according to input signals, such as X-Y allotters and printers. It has been adopted.

FIG. 1 shows a drive circuit and an excitation sequence when these conventional pulse motors, for example, a four-phase pulse motor, are operated in a two-phase excitation system.

In FIG. 1 (5), the first input from Naruko (11)
Drive output voltage u51, (IL Q
7), the bet state is (a), ■, in Figure 1 (B)), (
The rotor of the pulse motor changes as shown in (a), and the drive output voltage of the pulse motor rotor receives suction force (repulsion force) sequentially from the phase that is in the JN state. The rotation is stopped and positioning is performed.A control signal for forward rotation or reverse rotation is input from the terminal (2), and the drive output voltages us and tte are input.

(17)% The phase of u8+ changes, and the rotation direction of the pulse motor can be changed.

When the predetermined positioning operation is completed and the pulse of the reference signal (t) stops, the output signal of the monostable multivibrator (3) triggered by the pulse immediately before the stop changes to the resistance (it).
) and the time constant determined by the capacitor (CI) from time to to time 1. By setting the high level between times 10 and 18 to be larger than the four periods in the reference signal, the monostable multivibrator (3)
The output signal of is in a high level state from being triggered by the first pulse in the reference signal until time t1, and the AND gates (6), (7), (8), (9) in Fig. 1 (5)
The output signal of the D-type flip-flop (41
, (51 output signal is directly transmitted to the amplifier circuit αυ, Q5.
C1:i, input to (14). Also, time t, time t! This is the period during which the pulse motor is stopped. At this time, when the pulse motor is rotating, a predetermined power supply is naturally necessary, but power supply is not necessarily required during the stop period.

Regarding the method of stopping the nozzle motor after the completion of the positioning operation, the following three methods are generally used during the stop period shown in FIG. 1(B).

In the high level (■H) stopping method, the output of the drive circuit during the stopping period is maintained at the state immediately before stopping, and the output signals of the D-type frits 7 flops (4) and (5) are directly passed to the amplifier circuit 0υ. , 0 general asX (141), so in the drive circuit of Fig.
In order to prevent rotation of the pulse motor during the period when the pulse motor is stopped and the pulse motor is stopped, the switcher recess for switching the voltage level for supplying power to the pulse motor is no longer necessary and can be simplified. The pulse motor and drive circuit generate heat, and the power supply capacity and heat dissipation countermeasures are expensive.

In the stopping method at low level (VL), the positioning state IIAf even after stopping: the lowest drive output voltage (VL) that can be maintained
f: In the case of supply, AND gate t161, (7)
, (8), and (9) are not required, but as shown in Figure 1 (5), a switch IJI for switching the voltage level synchronized with the output of the monostable multivibrator (3) is required. The switch Ql, which switches the dynamic voltages of the amplifier circuits αυ, α, a, and I, is a technically sophisticated and expensive item that switches a high-power portion.

The stopping method at level (VO) is effective in situations where the load does not drop, such as when trying to rotate the pulse motor even after stopping, but for actual use, mechanical positioning #& A structure is required. In this case, the switch Ql for switching the voltage level shown in FIG. 1(5) becomes unnecessary.

As mentioned above, conventional stopping methods have various drawbacks.

Also, as a method for driving pulse motors for equipment that requires precise control, it is possible to increase the frequency and mechanical resolution of the reference signal, regardless of the response characteristics and resolution of the pulse motor itself, and to increase the speed of moving objects. Microstep control is used because it allows movement and provides high resolution.

FIG. 2 shows a drive circuit for performing microstep control, and FIG. 3 shows an excitation sequence for each part in FIG.

In the figure, (1111 is a counter operated by reference signal cK1, and each output signal of counter al is exclusive (Exclusive) OR gate ■, C21)
, w, and the reference signal CK2 is input to the other terminal. Therefore, each output signal of the exclusive OR gates ■, #]) and (A) is
As shown in FIGS. AXB and AXC, the signal is inverted only during the /1 level period of the reference signal CKZ. The output signals of XCluge 70 game [1, 9υ, 4] are input to decoder 4, and the binary coded octal code f: 0° 1.2.3.
4. Output from each Naruko in 5.6.7. Note that each input signal to the decoder (E) is connected to the power supply voltage of the decoder via resistors ■, (C), and (A), and the decoder (E) is connected to the power supply voltage of the decoder (
c) The threshold voltage is defined as the threshold voltage (thre-sbold). Each output signal of the decoder 4 is inputted to the operational amplifier 7 through the resistors □□□ to -, and simultaneously to the operational amplifier 7 via the resistors . The values of resistance (c) to (b) and resistance (to) to (6) are shown as resistance)>resistance (c)>...>resistance (b) and resistance-<resistance (to)... ...<By setting the resistor 4 to an appropriate value, a stepped waveform can be obtained.

The self-cutting signal of the operational amplifier is input to the operational amplifier) and the operational amplifier (g), and output signals X and X are obtained, respectively. Similarly, the output signal of the operational amplifier is inputted to the operational amplifier and the operational amplifier (9), and the output signal Y,
,Y, is obtained. Output signal X, and output signal Y,
, Y, are shown in Figure 3. As shown in , there is a phase difference of 180°. The output signals X1, X, and the output signal Y11Y are respectively switched by the switch □□□, (g) and 6η, as the drive output voltage to each phase of the pulse motor.
Step-like waveforms shown in FIG. 3, P, , Pt and P, , P4 are output from the mallet. Switch 4, Frequency and Switch 6
υ, 62 is the signal S1, S, and the signal S, , S.

The switches 611 and 6 are opened and closed alternately. Signal S1 is a signal input from terminal Q and passed through inverter 6, and is signal S.

is the signal □ itself input from terminal 〇, similarly, signal S is the signal input from Naruko (b) that has passed through the inverter, and signal S4 is the signal itself input from Naruko system. It is. Note that the signal 81.8. and signal S3.84 are signals as shown in Figure WS3, are pulse signals having the same period and a phase difference of 90° as the output signals X, , XI and the output signals Y, , Y, . Then, the rotation direction is changed by relatively advancing and delaying the phase of the signals inputted from the terminals 641 and 641.

However, in the conventional drive circuit for performing microstep control as shown in FIG. 2, the stopping period after the completion of the positioning operation is the same as the stopping method at level α, ) in FIG. 1(B), It had various drawbacks f: similar to those described above. .

The present invention has been made in view of the above-mentioned drawbacks, and provides a pulse motor drive control circuit that reduces power consumption by reducing the drive output voltage during the stop period after the completion of the positioning operation of the pulse motor. It is.

FIG. 4 is a circuit diagram showing an embodiment of the present invention, and FIG. 5 is an equivalent circuit diagram of a decoder based on the embodiment of FIG. This configuration is connected to the power supply voltage Vcc.

Hereinafter, the present invention will be specifically explained based on Examples.

In the figure, 1υ is a counter, tl, 11- is an exclusive OR gate, related is a decoder, -~0 and ct4
j-sυ is a resistor, +8a and IU are operational amplifiers, and have the same function f:f as the drive circuit shown in FIG. In diagram W-4, the reference signal CK1 is the counter shadow υ
At the same time, when the signal is input to the monostable multivibrator, it is supplied as a trigger signal for the monostable multivibrator constituted by the NAND gate (b) and -. The transistor state is switched by the output signal of the monostable multivibrator, and when the transistor (c) is in the ON state, the power supply voltage of level ■ is applied to the decoder branch, and the OF
In the F state, a lower vL level power supply voltage is applied to the decoder via the diode ring. Therefore, the resistance -
By setting the pulse of the monostable multivibrator to be larger than the four rules of the reference signal CKl using a capacitor, the transistor is maintained in the ON state when the reference signal CKI is continuously input and the pulse motor is rotating. A power supply voltage of level 1 is applied to the decoder. In addition, when the input of the reference signal CKI is stopped and the pulse motor is stopped, the monostable multivibrator is activated by the pulse immediately before the reference signal CK1 stops, and the pulse period is determined by the constant of the capacitor. After the pulse is output, the transistor (C) becomes OFF, and the power supply voltage applied to the decoder switches from the level 2 to the level vL.

The output voltage levels (1) and (2) of the output signals X and Y of the operational amplifier track and the operational amplifier zero in FIG.

It can be expressed as . Here, ■cc is the power supply voltage, ■
P is the potential difference between the emitter and collector of the transistor constituting the decoder, or between the drain and source of the field effect transistor; P is the feedback resistance of operational amplifier i8;a; Kn is the input resistance of operational amplifier 1821; The feedback resistance of , Rm is the input resistance of ORA 7~.

Therefore, from the lit, t2+ formula, the output voltage levels ■ and ■ are proportional to the power supply voltage Vcc, so the power supply voltage V
By controlling cc, the drive output voltage of the pulse motor can be controlled.

FIG. 6 shows an excitation sequence based on the embodiment of FIG.

As soon as the positioning is completed with the last pulse of the reference signal CKI rising at time t, the NAND gate (b), which is triggered at time t, is determined by the resistance of the monostable multivibrator formed by - and the capacitor. Output signals X and Y are held only during the pulse (between times 1 and 1),
Time 1. The reference signal CKI pulse starts again from time t4. Until the decoder power supply voltage Vcc is ■
, level is switched to ■, level, and output signal XSY
voltage level decreases. Further, the output signals X and Y obtained in FIG. 4 are processed by using a circuit similar to the circuit shown in FIG. 2, and a drive signal R for the pulse motor is obtained. Therefore, the obtained drive output voltage can be set to a sufficiently low drive output voltage that can maintain the positioning shape U during the stop period (time 141°).

As described above, in the present invention, in a drive circuit that performs microstep control of a pulse motor, the drive output voltage decreases during the stop period after the completion of positioning operation at a predetermined position, resulting in rapid reduction in power consumption. It is possible. Furthermore, a decoder with relatively low power consumption as in this embodiment
Since the drive output voltage is controlled by controlling the voltage, the control circuit for controlling the power supply voltage is simple, and there is no need for conventional high-class changeover switches, etc., and it can be realized at a low price. χ Big effect t- Deeper.

[Brief explanation of the drawing]

Figure 1 shows the conventional pulse motor drive circuit 4 and the excitation sequence, Figure 2 shows the pulse motor drive circuit using microstep control, and Figure 3 shows the pulse motor drive circuit shown in Figure 2.
4 shows a pulse motor drive control circuit according to the present invention, FIG. 5 shows an equivalent circuit diagram of the decoder shown in FIG. 4, and FIG. 6 shows an excitation sequence based on the pulse motor drive circuit shown in FIG. 4. [There is. (3) Monostable Maruna vibrator 4, -1 wheel, 6
υ, 64 Switch Ql, recommendation υ Counter ■, eυ, 翰, 14.5, - Exclusive OR
4 gates, ring decoder, goose, -1-1θ force, decoy, 18 - operational amplifier 1)i
41. I# NAND Gate Resistor 6η Capacitor Threat Transistor ■ Diode Procedural Amendment (Method) June 2, 1957 Director General of the Patent Office Special Axis No. 57-17264 2 Title of Invention Pulse Motor Drive Control Circuit 3, Amendment Relationship with the Ministry case Patent applicant Address: 1-7-4 Yukitani Otsuka-cho, Ota-ku, Tosui-gun, 145
Date of amendment order: May 7, 1980 (Delivery date: May 25, 1980) 5. Target drawing of m positive 6, Contents of amendment 471-

Claims (1)

[Claims] a monostable multivibrator activated by a reference signal;
The switch circuit includes a switch circuit that opens and closes according to the output signal of the monostable multivibrator, a counter that counts the reference signal, and a decoder that converts the output signal of the counter to a code, and the power supply voltage of the decoder is switched by the switch circuit. 1. A drive control circuit for a pulse motor, characterized in that the circuit is configured to