JPH02246795A - Motor controller - Google Patents

Abstract

PURPOSE:To reduce power consumption and to employ only one power supply system by providing a switching power supply connected with a series circuit of control switching elements, phase coils and drive switching elements, and a discharge resistor connected in parallel with the control switching elements. CONSTITUTION:During operation of a motor 11, load current flows through a control transistor 16 and output voltage of a switching power supply 17 is held stably. When the motor 11 is stopped, the control transistor 16 is turned OFF. Two of drive transistors 12-15 are held in ON state and two other transistors are held in OFF state. But holding current flows through a discharge resistor 18 and the drive transistor 16 under ON state to phase coil thus holding the motor 11 in stopped state and holding the output of the switching power supply 17 stably. Since relatively low holding current flows through the discharge resistor 18 during stopper of the motor 11, power consumption of the discharge resistor 18 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motor control device using a switching power supply.

C. Prior Art] Conventionally, this type of motor control device shown in FIG. 2 is known. This is each phase coil la, lb of motor 1,
One ends of lc and ld are connected to the collectors of drive NPN transistors 2, 3, and 4.5, respectively, and the other ends are commonly connected to the collector of a control PNP transistor 6. The emitters of the drive transistors 2 to 5 are grounded, and the emitter of the control transistor 6 is connected to the VM terminal of the switching power supply 7. The switching voltage R7 controls, for example, the on/off duty ratio of a transistor to output a predetermined voltage.

A discharge resistor 8 is connected between the VM terminal and the GND (ground) terminal of the switching power supply 7.

A VCC terminal having a voltage lower than the voltage output from the VM terminal of the switching power supply 7 is connected to the respective phase coils la, lb, and lc via a diode 9.

It is connected to the other end of 1d.

In this circuit, a motor control signal is input manually to the base of the control transistor 6, and a drive signal is input to the base of each drive transistor 2 to 5, so that the motor 1 is driven by a two-phase excitation method. It has become.

That is, as shown in FIG. 3(a), when the motor control signal becomes low level, the control transistor 6 is turned on, and in this state, the drive signal turns on each of the drive transistors 2 to 5 in a two-phase excitation mode. The coils la and lb of each phase are turned off.

(b), (e), (d) in Figure 3 are used for lc and ld.
, (e) flow periodically in a predetermined order, and the motor 1 is operated.

Further, when the motor control signal becomes high level, the transistor 6 is turned off and the operation of the motor 1 is stopped. When the operation of the motor 1 is stopped, two of each drive transistor 2 to 5 are held in the on state, and the VC
A relatively low voltage is applied to the C terminal to maintain the motor 1 in a certain phase state. In Fig. 3, the phase coils of A phase and B phase
b.

] A relatively small holding current flows through d to keep the motor 1 stopped.

Even if the control transistor 6 is turned off, the discharge resistor 8
By passing the load current through the switching power supply, the output voltage from the switching power supply is kept stable. In other words, the output voltage of a switching power supply becomes unstable unless negative current is constantly flowing, but when the motor is stopped, the load current can be passed through the discharge resistor, so the output voltage remains stable. become.

[Issue 8 to be solved by the invention] However, in the case where the discharge resistor 8 is directly connected to the output terminal of the switching power supply 7 to flow the load current, the power consumption in the discharge resistor is large, and the GILLS power as a whole is reduced. There was a growing problem. Further, in order to keep the motor 1 stopped, a power source for obtaining VCC is required in addition to the switching power source 7, and there is a problem in that two systems of power sources are required.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a motor control device that can reduce power consumption and require only one power source.

[Means for Solving the Problems] The present invention provides coils connected in series to one end of each phase coil of a motor, and periodically turned on and off in a predetermined order during operation of the motor.
A plurality of drive switching elements that are turned off and held in an on state and an off state when the motor is stopped, and a control switching element that is commonly connected to the other end of each phase coil and is turned on when the motor is operating. A switching power source is connected to a series circuit of a control switching element, each phase coil, and each drive switching element, and a discharge resistor is connected in parallel to the control switching element.

[Function] In the present invention having such a configuration, 1. The drive switching element is turned on, and each drive switching element is periodically turned on and off in a predetermined order, so that the coils of each phase are energized periodically in a predetermined order, and the motor is rotated. Ru.

When the motor is stopped, the control switching elements are turned off, a portion of each drive switching element is kept on, and the rest are kept off. As a result, a holding current flows from the switching power supply to the corresponding phase coil via the discharge resistor and the drive switching element held in the on state, and the motor is held in the stopped state. In this way, since the load current flows even when the motor is stopped, the switching power supply can output a stable voltage.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, each phase coil 11a of the motor 11,
One ends of llb, llc, 11d are connected to retrieving NPN transistors 12, 13, 14, . 15, and the other end is commonly connected to the collector of a control PNP transistor 16.

The transmitter of each of the drive transistors 12 to 15 is grounded. The emitter of the control transistor 16 is connected to the VM terminal of the switching power supply 17.

A discharge resistor 18 is connected between the emitter and collector of the control transistor 16.

The control transistor 16 is turned on and off by the same motor control signal as shown in FIG. , it is supposed to work off. For example, the motor 11 is driven by a two-phase excitation force type.

In this embodiment having such a configuration, when the motor 11 is operated, the control transistor 1 is activated by the motor control signal.
6 is turned on. Each of the drive transistors 12 to 15 is periodically turned on and off in a predetermined order, and the motor 11 is rotationally driven by a two-phase excitation force type.

When the motor 11 is in operation, a load current flows through the control transistor 16, so that the output voltage of the switching power supply 17 is maintained stably.

Further, when the motor 11 is stopped, the control transistor 16 is turned off. In addition, each drive transistor 12~]5
Two of them are kept on and the remaining two are kept off.

However, a holding current flows to the phase coil through the discharge resistor 18 and the drive transistor in the on state, and the motor 11
is held in a stopped state. Since the holding current flows in this manner, a load current flows to the switching power supply 17, so that the output voltage of the switching power supply 17 is maintained stably even when the motor 11 is stopped.

Moreover, since a holding current of a relatively small current value flows through the discharge resistor 18 only when the motor 11 is stopped, power consumption in the discharge resistor 18 is reduced. Therefore, the overall power consumption can be reduced.

Further, as a power source, it is sufficient to use only one switching power source. Therefore, the configuration becomes simple and economical efficiency can be improved.

[Effects of the Invention] As detailed above, according to the present invention, there is provided a motor control device that can reduce the power consumption by the discharging resistor to reduce the overall power consumption, and can reduce the required power supply to a single system of switching power supply only. It is possible to provide

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part showing an embodiment of the present invention, FIG. 2 is a circuit diagram of a main part showing a conventional example, and FIG. 3 is a waveform diagram showing operation waveforms of each part in FIG. 11...Motor, lla~lid...Motor phase coil, 12~15...Drive transistor, 16...
...Control transistor, 17...Switching power supply, 18...Discharge resistor. Figure 11 Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] Multiple drive switching devices are connected in series to one end of each phase coil of the motor, and are periodically turned on and off in a predetermined order when the motor is operating, and are maintained in the on and off states when the motor is stopped. element, a control switching element that is commonly connected to the other end of each of the phase coils and is turned on when the motor is operating, and connected to a series circuit of the control switching element, each phase coil, and each drive switching element. What is claimed is: 1. A motor control device comprising: a switching power supply configured to control a motor; and a discharge resistor connected in parallel to the control switching element.