JPH0767391A - Motor driver circuit - Google Patents

Abstract

PURPOSE:To provide a motor driver circuit without generation vibration and noise even if a motor is used at a high rotation region (1 kpps or higher) using the control by regeneration damping. CONSTITUTION:The title circuit controls the drive of a stepping motor for plotter by inputting the pulse width modulation waveform of input sinusoidal wave to an H bridge 12 and then operating the H bridge 12 and performs the feedback control of the input sinusoidal wave by the feedback loop from the H bridge 12 with an integration circuit 18 for controlling the pulse width modulation waveform. Therefore, the H bridge 12 is connected for regenerative damping and at the same time a capacitor 20 is provided at the downstream position from the integration circuit 18 within a feedback loop.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driver circuit, and more particularly to controlling the drive of a motor used in a high rotation range such as a stepping motor such as a pen plotter or a cutting plotter. The present invention relates to a motor / driver circuit suitable for use in.

[0002]

2. Description of the Related Art Generally, in a motor driver circuit for driving a stepping motor such as a pen plotter or a cutting plotter, for example, an H bridge as shown in FIG. 2 is used. The H bridge is provided with switch parts I to IV composed of transistors, and the drive of the motor M is controlled by appropriately turning on / off the switch parts I to IV.

As a control method for controlling the motor M by inputting a pulse width modulation (PWM) waveform of an input sine wave into the above H bridge, there are control by dynamic braking and control by regenerative braking. Is known to do.

Of the above two control methods, the control by dynamic braking means that the PWM waveform is input to the switch section I (or switch section II) to turn it on / off by the PWM control, and the switch section IV (or switch section). Part III) is always on.

The control by the dynamic braking is performed by the switch unit I.
Will be described below by taking as an example a case in which the switch section IV is constantly turned on while being turned on / off by PWM control.

First, when the switch unit I is in the ON state, the switch unit IV is also in the ON state, and at this time, a current flows as shown by the broken line in FIG. On the other hand, even when the switch unit I is off, the switch unit I
V is in the ON state, and at this time, a current (regenerative current) flows as indicated by the alternate long and short dash line in FIG.

That is, when the PWM waveform as shown in FIG. 4 (a) is inputted to the switch section I, the current waveform of the motor M becomes as shown in FIG. 4 (b).

Therefore, in the case of controlling the motor M by the above-described dynamic braking, as can be understood from FIG. 4B, the regenerative current of the regenerative current is Since the consumption is delayed, the current remains in the H-bridge, and the ideal sine curve as the current waveform collapses.

As a result, the vibration and noise of the motor become large, and the current followability is not so good, so that it is not suitable for controlling a motor used in a high rotation range (1 kpps or more). Was pointed out.

On the other hand, the control by regenerative braking means that the switch unit I (or switch unit II) and the switch unit IV (or switch unit III) are turned on / off simultaneously by PWM control.
It is to turn it off.

This regenerative braking will be described below by taking as an example the case where the switch section I and the switch section IV are turned on / off by PWM control.

First, when the switch section I and the switch section IV are in the ON state, a current flows as shown by a broken line in FIG. On the other hand, the switch unit I and the switch unit IV
When and are in the off state, a current (regenerative current) flows as shown by the alternate long and short dash line in FIG.

That is, when the PWM waveform as shown in FIG. 6A is inputted to the switch section I and the switch section IV, the current waveform of the motor M becomes as shown in FIG. 6B. .

Therefore, in the case of controlling the motor M by the above-mentioned regenerative braking, as can be understood from FIG. 6 (b), the consumption of the regenerative current is the switch portion I and the switch portion IV.
And are very close to the rising speed of the current when on. For this reason, compared with the control of the motor M by dynamic braking, the regenerative current is consumed faster and the followability of the current in the H bridge is improved, so that a current waveform close to a sine curve can be obtained.

As a result, the vibration and noise of the motor can be reduced, and the current followability is good, which is suitable for controlling the motor used in a high rotation range (1 kpps or more). It was pointed out.

Among such control methods of dynamic braking and regenerative braking, generally, control by dynamic braking has been adopted to control the driving of the motor. That is, a general motor is rarely used in a high rotation range (1 kpps or more), and the circuit configuration of dynamic braking is simpler than that of regenerative braking, and the cost can be easily reduced. Therefore, the control based on the dynamic braking was adopted.

[0017]

However, in the case of the control by the dynamic braking, the vibration and noise of the motor are inevitably large, and moreover, in the high rotation range (1 k
Since it has characteristics that it is not suitable for a motor used at pps or more), the application is limited accordingly. Especially, a pen plotter or cutting plotter that uses the motor up to a high rotation range (1 kpps or more) There was a problem that it could not be applied to the control of the stepping motor.

For this reason, the high rotation range (1 k
It has been proposed to use control by regenerative braking to control a stepping motor used at pps or more).

However, in general, in order to control the drive of the motor by the regenerative braking of the H bridge, it is necessary to provide a feedback loop from the H bridge to control the PWM waveform input to the H bridge with current. In this case, since it is necessary to provide an integrator circuit in the feedback loop, the presence of this integrator circuit causes a phase delay in the value indicated by the feedback control, and the motor is used in the high rotation range. The more the current is disturbed, the more the current is disturbed, which causes vibration and noise.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to use control by regenerative braking to achieve a high rotation range (1 kp).
It is intended to provide a motor driver circuit that does not generate vibration or noise even when the motor is used at a speed of ps or more).

[0021]

In order to achieve the above object, a motor driver circuit according to the present invention inputs a pulse width modulation waveform of an input sine wave into an H bridge,
A motor driver circuit for operating a bridge to control the drive of a motor, wherein the motor driver circuit includes an integrating circuit.
In the motor driver circuit that controls the input sine wave by the feedback loop from the bridge and controls the pulse width modulation waveform,
The H bridge is connected so as to perform regenerative braking, and a capacitor is arranged at a position downstream of the integrating circuit in the feedback loop.

[0022]

The phase delay of the indicated value by the integrating circuit provided in the feedback loop is compensated by the capacitor provided in the feedback loop at a position downstream of the integrating circuit.

Therefore, it has a characteristic of control by regenerative braking that is suitable for a motor used in a high rotation range (1 kpps or more), and can compensate a phase delay of an instruction value in a feedback loop for current control. Even if the motor is used in a high rotation range (1 kpps or more), it is possible to reliably prevent the generation of vibration and noise.

[0024]

Embodiments of the motor driver circuit according to the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a motor driver circuit for a pen plotter or cutting plotter according to an embodiment of the present invention.
Stepping motor used for plotter (hereinafter,
It is called a "stepping motor for plotters". ) 10
It is a motor driver circuit used to drive the. Here, the plotter stepping motor 10 is used in a high rotation range (1 kpps or more).

H in this motor driver circuit
The bridge 12 is connected so as to be controlled by regenerative braking. That is, P for the switch unit I and the switch IV
The WM waveform is input so that it is turned on / off at the same time by PWM control, and the PWM waveform is input to the switch section II and the switch section III so that it is turned on / off at the same time by PWM control. There is.

The ON / OFF relationship between the switch section I and the switch IV and the switch section II and the switch section III is as follows. Switch part I
I and the switch unit III are turned off, and the switch unit I and the switch unit IV are turned off, the switch unit II
And the switch unit III are turned on.

In the feedback loop extended from the current detecting resistor 14 of the H-bridge 12, a current is fed so that it can be used for current control in the differential amplifier 16 to which a reference sine wave is input. Detection resistor 1
An integrating circuit 18 is provided for integrating the pulsed output waveform obtained from No. 4 of FIG.

The differential amplifier 16 includes an integrating circuit 1
A comparator 22 is connected via a capacitor 20 for compensating the phase delay caused by 8 and the comparator 22 outputs the sine signal output from the differential amplifier 16 via the capacitor 20 based on a known technique. The PWM waveform is generated and output by the wave and the triangular wave.

Further, the PWM waveform output from the comparator 22 is input to the AND gates 24a and 24b. And these AND gates 24
a and 24b are controlled by a pulse-shaped phase signal A and a phase signal A ′ having a phase opposite to that of the phase signal A, and the AND gate 24a is opened only while the phase signal A is in the ON state, while The AND gate 24b is opened only while the phase signal A and the opposite phase signal A ′ are in the ON state, and the comparator 22 is provided in the switch unit I and the switch IV and the switch unit II and the switch unit III of the H bridge 12.
The PWM waveform output from is selectively supplied.

In the above configuration, the differential amplifier 16 has
A sine wave is input and feedback is applied from the current detection resistor 14 of the H bridge 12.

At this time, since the feedback loop is provided with the integrating circuit 18, a phase delay occurs in the output from the integrating circuit 18, but the capacitor 20 restores this phase delay to the original. Then, it becomes possible to perform phase compensation.

Therefore, the comparator 22 can obtain the PWM waveform by the sine waveform and the triangular wave in which the phase delay is eliminated, based on a known technique.

The output of the comparator 22 is A
The AND gate 24a is opened only during the period when the pulsed phase signal A is input to the ND gates 24a and 24b, while the phase signal A and the opposite phase signal A'are on. The AND gate 24b will open.

Therefore, when the AND gate 24a is open, the switch section I and the switch section I of the H bridge 12 are based on the PWM waveform output from the comparator 22.
When V and V are turned on, the switch unit II and the switch III are turned off.

On the other hand, when the AND gate 24b is opened, the switch section II and the switch section III of the H bridge 12 are turned on based on the PWM waveform output from the comparator 22, and the switch section I and The switches IV and IV are turned off.

As described above, the H bridge 12 controls the ON / OFF of the switch unit I, the switch unit II, the switch unit III, and the switch IV, so that the drive of the plotter stepping motor 10 is controlled by regenerative braking. It

[0038]

Since the present invention is constructed as described above, it has the following effects.

A motor driver circuit for inputting a pulse width modulation waveform of an input sine wave to an H bridge and operating the H bridge to control the drive of a motor, which is a feedback loop from the H bridge equipped with an integrating circuit. In the motor driver circuit that controls the input sine wave by feedback to control the pulse width modulation waveform, connect the H bridge to regenerative braking and place it in the feedback loop at a position downstream of the integrating circuit. Since the capacitor is installed, the phase delay of the indicated value by the integrating circuit provided in the feedback loop is compensated for the phase by the capacitor provided downstream of the integrating circuit in the feedback loop. Become.

Therefore, it has a characteristic of regenerative braking that is suitable for a motor used in a high rotation range (1 kpps or more), and can compensate a phase delay of an instruction value in a feedback loop for current control.
Even if the motor is used in a high rotation range (1 kpps or more), it is possible to reliably prevent the generation of vibration and noise.

That is, according to the motor driver circuit of the present invention, the control by regenerative braking is used, and the high rotation range (1 k
It is possible to provide a motor driver circuit that does not generate vibration or noise even when using a motor at (pps or more), so that, for example, a stepping motor such as a pen plotter or a cutting plotter can be provided. It is extremely effective when used to control the drive of a motor used in a high rotation range.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a motor driver circuit according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an H bridge.

FIG. 3 is an explanatory diagram showing a current path of an H bridge due to dynamic braking.

FIG. 4 is an explanatory diagram showing an input waveform (FIG. 4A) and a motor current waveform (FIG. 4B) in FIG.

FIG. 5 is an explanatory diagram showing a current path of an H-bridge due to regenerative braking.

6 is an explanatory diagram showing an input waveform (FIG. 6A) and a motor current waveform (FIG. 6B) in FIG.

[Explanation of symbols]

 10 Plotter Stepping Motor 12 H Bridge 14 Current Detecting Resistor 16 Differential Amplifier 18 Integrating Circuit 20 Capacitor 22 Comparator 24a AND Gate 24b AND Gate

Claims (1)

[Claims] 1. A motor driver circuit for inputting a pulse width modulation waveform of an input sine wave to an H bridge and operating the H bridge to control the driving of a motor, wherein the H driver includes an integrator circuit. The feedback loop controls the input sine wave with feedback,
In a motor driver circuit adapted to control a pulse width modulation waveform, the H bridge is connected so as to perform regenerative braking, and a capacitor is arranged at a position downstream of the integrating circuit in the feedback loop. Motor driver circuit characterized by.