JPS609439B2 - 4-phase pulse motor drive circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a drive circuit for a four-phase pulse motor, particularly a battery-operated drive circuit, and aims to provide a drive circuit with low power consumption.

Conventionally, as a battery-operated four-phase pulse motor drive circuit,
As shown in FIG. 1A, a two-phase flip-flop circuit 2 is triggered by the output clock pulse of the clock pulse generator 1 to generate signals having a phase of 90 degrees to each other, and these signal outputs Q, , There is a circuit in which the transistor switches Tr, ~Tr4 are switched by Q,, Q2, and Q2, respectively, and current is sequentially caused to flow from the power supply battery B to each stator coil of the four-phase pulse motor 3 via the above-mentioned Tr, ~Tr4. Generally used.

The time chart of the current in each part of the drive circuit is as shown at the beginning of FIG.
The output Q, of the two-phase flip-flop 2 has a waveform shown in FIG.

Also, the output Q2 has a waveform d with a phase difference of 90 degrees from Q, and the output Q2 has a waveform e with a phase difference of 270 degrees from Q.
A waveform of Transistor switch Tr・~Tr
4 are switched by the outputs of Q, , Q, , Q2, and Q2, respectively, so these switches Tr
, ~ Tr4 to each stator coil of the four-phase pulse motor 3 have the same waveforms as the waveforms b to e, respectively. Therefore, the current flowing through battery B has a waveform f which is the sum of the currents b to e at each time, and since this is always constant, the power consumption of this circuit is also always a constant value. However, depending on the type of load on the pulse motor, it may not be necessary to constantly flow current from battery B.

For example, when the recording paper of a recording instrument is fed by a pulse motor, the rotation speed is relatively low, and the force to lock the motor rotor is not required during the period when the motor is at rest. . For such loads,
Only a part of the power consumption in the drive circuit shown in FIG. 1A contributes to the generation of rotational torque, and most of it becomes a loss, resulting in an increase in the temperature of the equipment and a waste of power. The present invention provides a low power consumption drive circuit that eliminates the above-mentioned drawbacks of the conventional four-phase pulse motor drive circuit.
An example thereof is shown in FIG. 2A.

Figure 2A is an improved version of the circuit in Figure 1A,
The improvement is that a resistor R and a diode D are connected between each output Q, , Q, , Q2, Q2 of the two-phase flip-flop of the circuit shown in FIG. A monostable multipipulator 4 triggered by a clock pulse is added between the clock pulse generator 1 and the diode D.
is inserted, and the control of this gate is controlled by the output pulse of the monostable multipipelator 4.

As is clear from the figure, in the above gate, the diode operates in the forward direction while the clock pulse is not output, and the diode does not operate while the clock pulse is output. Therefore, each output signal of a two-phase flip-flop is
Each time a clock pulse is output, it is applied to the input of the transistor switch for only the duration of that pulse width, causing the switch to conduct. Since the output pulse of the monostable multipipelator 4 has a pulse width determined by its time constant, by selecting the output pulse width of the monostable multipipelator to the minimum width necessary to obtain the required torque, The power consumption of the drive circuit is intermittent regardless of the pulse width of the clock pulse, and the power consumption is much lower than that of the circuit shown in FIG. 1A. Figure 2 shows the current time chart of each part of the circuit shown in Figure 1. In the figure, a' is the output pulse of the monostable multipipulator, and a and b to f are the same as those in Figure 1. It shows the current.

In the circuit shown in FIG. 2A, even if the frequency of the clock pulse is arbitrarily changed, the rate of reduction in power consumption is not affected. Based on this invention, a clock pulse generator, a two-phase flip-flop, a monostable multipipulator, etc. can all be integrated into a C-MOSC.
We prototyped a drive circuit using this and operated a dual-purpose AC/DC pen recorder. The results showed that at low speed recording paper feed, the total power consumption of the drive circuit was less than half of the power consumption of the conventional circuit, and the motor There was almost no heat generation, and the battery could be used for a long time.

[Brief explanation of drawings]

FIG. 1A shows a conventional pulse motor drive circuit, the beginning of the figure shows a time chart thereof, and FIG. Figure 1 Figure 2

Claims (1)

[Claims] 1. A clock pulse generator, a two-phase flip-flop circuit that is triggered by the clock pulse output from this generator and outputs signals with a phase difference of 90 degrees, and switching that is controlled by each output signal of this circuit. In a pulse motor drive circuit consisting of a switching element and a circuit that sequentially supplies current to the stator coil of a four-phase pulse motor via each switching element, there is a circuit between each output terminal of the two-phase flip-flop circuit and each of the switching elements. A four-phase pulse motor drive circuit comprising a gate circuit, a monostable multivibrator triggered by the clock pulse, and an output pulse of the monostable multivibrator to control the gate.