JPH06235756A - Inspecting circuit for rotating condition of dc motor - Google Patents

Abstract

PURPOSE:To provide a circuit for inspecting the state change of a motor with a one-piece circuit by utilizing a backward induced voltage which is generated at an armature coil winding. CONSTITUTION:The circuit is provided with a display lamp P and transistors Q1 and Q2 and an input terminal T and a selection switch S. A resistor R1 and the transistor Q1 are connected to the display lamp P, resistors R2 and R3 are connected to the transistor Q2, a capacitor C1 is connected to a node N1. and a circuit including the transistor Q2 is connected to the DC connection part of the display lamp P and the transistor Q1 in parallel. A backward induced voltage which is generated at an armature coil winding is input to a terminal T and a capacitor C2 and a plurality of resistors are connected. A switch S is provided with quick-acting switches S1 and S2 one of them is connected to the base terminal of the transistor Q1 and the node N1 and then a terminal A is connected to a terminal A'. The other is connected to a resistor R5 and the base terminal of the transistor Q2. The switch S is set as shown by a solid- line position when detecting the rotation according to the stop of the motor and a selection switch part and terminals B and B' are connected when detecting stop from the rotation of the motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for inspecting the rotation state of a DC motor, and more particularly to a circuit for inspecting the rotation state of the motor when it is stopped and the rotation state of the motor.

[0002]

2. Description of the Related Art When making a pass / fail judgment for a manufactured motor, the judgment is made by inspecting the rotation state of the motor. The inspection at this time is performed by, for example, detecting whether or not the motor is started and whether or not the motor is stopped in a state in which the motor must be rotating by an aging test or the like.

When detecting such a rotation state, it is necessary to detect two modes, that is, a stop to rotation state and a rotation to stop state. Therefore, conventionally, the inspection has been performed by using a circuit for separately detecting such a state, but the inspection circuit for such a rotation state has a problem described below.

[0004]

That is, in the above-described conventional inspection circuit, in order to detect the two modes, individual inspection sets are required, and their connection is troublesome. In addition, in such an inspection circuit, a sensor for detecting the rotation state of the motor is required, and as this kind of sensor, for example, a photoelectric sensor such as an encoder or an index magnet is mounted, but a magnetic sensor is adopted. However, the installation of these sensors has been troublesome.

The present invention has been made in view of the above problems, and an object of the present invention is to utilize a counter electromotive voltage generated in an armature winding by the rotation of a motor to integrate the elements. SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit for inspecting the rotation state of a DC motor, which can detect changes in two states of the motor with the above circuit.

[0006]

In order to achieve the above object, the present invention relates to a rotation state inspection circuit for a DC motor which detects a rotation state from stop of a motor and a stop state from rotation of the motor. An indicator lamp for displaying, a first transistor connected in series with this indicator lamp, and a serial connection part of the indicator lamp and the first transistor provided between a power source and ground, are connected in parallel, and the collector side A second transistor to which a voltage dividing resistor circuit and a capacitor are connected, an input terminal to which a back electromotive force generated in the armature winding by the rotation of the motor is input, and bases of the first and second transistors It is interposed between a terminal and the input terminal, and when the rotation state is detected from the stop of the motor, the base terminal of the first transistor and the input terminal are connected to each other. When detecting a stop state from rotation, the base terminal of the second transistor and the input terminal are connected to each other, and the node to which the voltage dividing resistor circuit and the capacitor are connected and the first terminal are connected to each other. It is characterized in that it has a changeover switch connecting between the base terminal of one transistor.

[0007]

According to the circuit for inspecting the rotation state of the DC motor having the above structure, when the stop state is detected from the rotation, the input terminal and the base terminal of the first transistor are connected by the changeover switch. When a back electromotive voltage is generated in the armature winding due to the rotation of the motor, the back electromotive voltage is applied to the base terminal of the first transistor to turn on the first transistor, thereby turning on the indicator lamp.

When detecting the stop state from the rotation, the changeover switch is used to connect between the base terminal and the input terminal of the second transistor, and the node to which the voltage dividing resistor circuit and the capacitor are connected and the first node. Since the back-induction voltage is applied to the base terminal of the second transistor while the back-induction voltage is generated in the armature winding due to the rotation of the motor, the back-induction voltage is applied to the base terminal of the second transistor. , The second transistor is turned on, but this transistor is connected in parallel to the part in which the indicator light and the first transistor are connected in series, so that the indicator light can be activated while the motor is rotating. Does not light.

On the other hand, when the rotation of the motor is stopped in the above connected state and the back electromotive voltage of the armature winding becomes equal to or lower than a predetermined value, the second transistor is turned off, which causes the voltage dividing resistor circuit and the capacitor to pass through. Then, the power supply voltage is applied to the base terminal of the first transistor, the first transistor is turned on, and the indicator light is turned on.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 5 show an embodiment of a circuit for inspecting the rotation state of a DC motor according to the present invention. The inspection circuit shown in the figure shows a case where the present invention is applied to a sensorless DC motor, and this type of DC motor normally has a stator (not shown) that generates a magnetic field in an excited state and a magnetic field of this stator. And a rotor (not shown) that obtains a rotational force by the electromagnetic interaction of.

Further, the stator is provided with a plurality of phases of armature winding, and when the motor is in a rotating state, the armature winding is linked to the magnetic flux of a magnet provided on the rotor side. A back electromotive force V ₁ is generated, and in the present invention, the back electromotive force V ₁ is used to detect the rotation state of the motor. The inspection circuit includes an indicator light P, a first transistor Q ₁ , a second transistor Q _2, and an input terminal T.
And a changeover switch S.

The indicator light P is composed of a light emitting diode, for example, and has a first resistor R ₁ connected to _one end thereof and a collector terminal of a _first transistor Q ₁ connected to the other end thereof. The first resistor R ₁ is connected to the power supply voltage V _cc , the emitter terminal of the first transistor Q ₁ is grounded, and the indicator light P and the first transistor Q ₁ are
It is connected in series.

The emitter terminal of the second transistor Q ₂ is grounded, and the collector terminal thereof is connected to the other ends of the _two resistors R _{2 and} R ₃ , one end of which is connected to the power supply voltage V _cc, and the other end of the resistor R _2. The other end of a _first capacitor C ₁ whose one end is grounded is connected to the node N ₁ to which _2, R ₃ are connected, and the circuit including the second transistor Q ₂ is It is connected in parallel to the portion where the first transistor Q ₁ is connected in series.

The input terminal T is connected to the electric machine by the rotation of the motor.
Reverse induced voltage V generated in the child winding₁Is input
Therefore, this input terminal T has a resistor R_FourConnected in series with
Second capacitor C₂And resistance R_Five, R₆Composed of and
Resistor connected to a fixed waveform shaping circuit and grounded at one end
R_FiveIs connected in parallel with a backflow prevention diode D.
And the resistance R_FiveAnd diode D are connected
Code N₂Has a resistance R ₆One end of is connected.

The changeover switch S is composed of two sets of interlocking switches S _{1 and} S _2. One of the switches S ₁ has a changeover switch portion connected to the base terminal of the first transistor Q ₁ and one of them. Terminal B is connected to the node N ₁ and the other terminal A is connected to the terminal A ′ of the switch S ₂ . The other switch S ₂ has a changeover switch connected to the resistor R ₅ and a terminal B ′ connected to the base terminal of the second transistor Q ₂ .

The change-over switch S thus constructed is
When the rotation state is detected from the stop of the motor, it is set as shown by the solid line position in FIG. 1, and in each of the switches S _{1 and} S ₂ , the changeover switch section and the terminals A and A ′ are connected, and When detecting the stopped state from the rotation of the motor, the changeover switch section and the terminals B and B'are connected. Next, the operation of the inspection circuit configured as described above will be described with reference to FIGS. First, when the rotation state is detected from the stop of the motor, the changeover switch S is set as shown by the solid line in FIG. 1, and in this state, the changeover switch S causes the input terminal T and the first transistor Q ₁ to move. Since the connection with the base terminal is made, the inspection circuit shown in FIG. 1 is substantially in the state shown in FIG.

In such a circuit, the input terminal T is
A pulse-shaped reverse induced voltage V as shown in FIG.₁Add
Then, the reverse induced voltage V₁Is a waveform shaping circuit
(C₂, R _Four,R_Five, D ) Shaped as shown in Figure 3
Then, the voltage shown in this figure becomes the resistance R₆Through the
1 transistor Q₁Applied to the base terminal of. That
And the voltage as shown in the first transistor Q₁The
The first transistor Q when applied to the source terminal.₁Is
It turns on when the voltage increases and turns off when the voltage decreases.
Then, it turns on and off at high speed, and the result is
As a result, the current shown in FIG.
Dista Q₁Flashes repeatedly with the on and off of
Since the blinking cycle is short, the indicator light P actually lights up.
State, which causes the motor to stop
Changes will be confirmed.

Further, when detecting the stop state from the rotation
Is the second transistor Q by the changeover switch S.₂The
Between the source terminal and the input terminal T, and the node N₁And the
1 transistor Q₁Connected to the base terminal of
Therefore, the inspection circuit shown in FIG. 1 is substantially the same as that shown in FIG.
Will be shown. In such a circuit, the input terminal T
In addition, the pulsed back electromotive force V as shown in FIG.₁But
When applied, this back electromotive force V₁Is a waveform shaping circuit
(C₂, R _Four,R_Five, D), as shown in FIG.
And the voltage shown here is the resistance R₆Second through
Transistor Q₂Applied to the base terminal of.

[0019] Then, the voltage as shown in
Register Q₂When applied to the base terminal of the
Register Q₂Is turned on when the voltage becomes higher,
When it gets low, it turns off, and you can turn it on and off at high speed.
Since this point period is short,
Back induced voltage V₁Will remain on while is added.
To continue.

At this time, the second transistor Q ₂ is connected in parallel to the portion where the indicator light P and the first transistor Q ₁ are connected in series, and the voltage applied to the collector terminal thereof is shown in FIG. since almost no change as shown, the first base terminal of the transistor Q _1, a low voltage only is applied, indicator P Therefore, since the first transistor Q ₁ is not turned on, the motor is rotating It does not light up during the period.

On the other hand, in the circuit shown in FIG. 4, when the rotation of the motor is stopped and the back electromotive force V ₁ of the armature winding becomes a predetermined value or less, the second transistor Q ₂ is turned off,
Accordingly the charging current flows into the capacitor C ₁ via the resistor R _2, the voltage of the node N ₁ becomes high, a predetermined voltage is applied to the first base terminal of the transistor Q _1, the first
The transistor Q _{1 of} is turned on, which causes the indicator light P
Lights up.

Therefore, when the indicator light P is turned on, the change from the rotation of the motor to the stopped state is confirmed. In the above embodiment, the waveform shaping circuit is connected to the input terminal T, but this waveform shaping circuit is used when a pulsed voltage in the HL state as shown in FIG. 4 is input. It is not always necessary to use the back electromotive force V ₁ generated in the armature winding as it is, but for example, a sinusoidal voltage from the armature winding or a pulsed state in which the L level is not at 0 potential It works effectively when voltage is input.

[0023]

As described above in detail in the embodiments,
According to the DC motor rotation state inspection circuit of the present invention, it is possible to detect changes in the rotation state of two modes in an integrated circuit by utilizing the back electromotive force generated in the armature winding of the motor. You can

[Brief description of drawings]

FIG. 1 is an overall circuit diagram showing an embodiment of an inspection circuit for a rotating state of a DC motor according to the present invention.

FIG. 2 is a circuit diagram when detecting a rotation state from stop of a motor in the circuit of FIG.

FIG. 3 is a waveform explanatory diagram of a main part in an operating state of the circuit of FIG.

FIG. 4 is a circuit diagram when detecting a stop state from rotation of a motor in the circuit of FIG.

5 is a waveform explanatory view of a main part in an operating state of the circuit of FIG.

[Explanation of symbols]

P indicator light Q ₁ first transistor Q ₂ second transistor N ₁ node T input terminal S switch

Claims (1)

[Claims] 1. A circuit for inspecting a rotation state of a DC motor, which detects a rotation state from stop of a motor and a stop state from rotation, and an indicator lamp for displaying a change of the rotation state, and a first indicator connected in series with the indicator lamp. A first transistor, a second transistor in which the indicator light and the first transistor, which are provided between the power supply and the ground, are connected in parallel, and a voltage dividing resistor circuit and a capacitor are connected to the collector side. A transistor, an input terminal to which a back electromotive voltage generated in the armature winding due to the rotation of the motor is input, and a base terminal of the first and second transistors and the input terminal. When detecting the rotation state from the stop, the base terminal of the first transistor is connected to the input terminal, and when detecting the rotation state from the rotation, the first terminal is connected to the first terminal. Of a connection between the base terminal and the input terminal of the transistor, and the voltage dividing resistor circuit and the and the capacitor and is connected to the node first
A circuit for inspecting the rotation state of a DC motor, the circuit having a changeover switch connected to the base terminal of the transistor.