JPS5822950B2 - It is difficult to understand the situation. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the rotational angular phase of a DC motor by using an impedance element and a diode.

Conventionally, in order to detect the rotational angle phase of a DC motor, a permanent magnet is fixed to the rotating shaft of the DC motor, and the rotation of the permanent magnet is detected using an induction coil, etc., or a phase detection method is used in the commutator of the DC motor. A special brush was installed for detection.

However, in any case, the device for detecting this cannot be easily installed, and the configuration of the DC motor must be changed in some way.

However, in order to ideally control a DC motor, it is necessary to obtain a signal proportional to the rotation of the DC motor from the DC motor, and it is desirable not to change the configuration of the well-known DC motor in order to obtain such a signal. be done.

The device of the present invention is intended to meet such demands.

Next, the rotational angle phase detection device for a DC motor having the above effect will be explained in order according to the drawings. Figs. 1 to 4 show circuits as embodiments of the rotational angle phase detection device for a DC motor, which is the device of the present invention. FIG. 1 shows the resistance R1
and the diode D1 are connected in series, and the resistor R1 and the diode D1 are connected in parallel with the DC motor 5, and the resistor R1, the diode D1, and the DC motor 5 are connected in parallel.
The terminals 8 and 9 to which the DC motor 5 is connected are connected to a power source for driving the DC motor 5.

A rotating shaft 1 of a DC motor 5 is supported by a bearing 4 made of oilless metal.

The brushes of the DC motor 5 are connected to the terminals 2 and 3, which serve as power supply terminals for the DC motor.

When a DC power source is connected to the terminals 8 and 9 in the circuit configuration as described above, a differential waveform as shown in FIG. 5 is obtained from the terminals 6 and 7.

In the differential waveform, when the DC motor 5 has three poles and is connected in a delta configuration, six pulses are obtained for one rotation of the rotating shaft 1.

The reason why the differential waveform shown in FIG. 5 is obtained will be explained in detail below.

FIG. 1c shows commutators 10-1 and 1 of the DC motor 5.
The positional relationship between brushes 2-1 and 3-1 and brushes 0-2 and 10-3 is illustrated.

The positional relationship between the commutators 10-1, 10-2, 10-3 and the brushes 2-1 and 3-1 in FIG.
1-3 is also pouring liquid into the brush 2-1.

Therefore, the commutators 10-1 and 10-2 shown in FIG.
, 10-3 Brush 2-1, positional relationship of 3-1, etc.
The impedance between -1° and 3-1 is the commutator IC1-1, 10-2, 10-3, brush 2-L3 shown in Figure 1.
The impedance is lower than the impedance between the brushes 2-1 and 3-1 in the positional relationship indicated by -1.

In other words, while the rotating shaft 1 of the DC motor 5 makes one rotation, the first
The positional relationship of the commutator and brush shown in the figure is 6 times, Figure 1C
The rectification and brush positional relationship shown in Figure 2 is also repeated six times.

Therefore, the armature current waveform of the DC motor 5 becomes as shown in FIG. 5a.

Therefore, the magnetic energy stored in the armature of the DC motor 5 is released, and the magnetic energy is discharged through the diode DI and the resistor R1.

This discharged electrical signal is the differential waveform electrical signal shown in FIG. 5d.

In this way, since the electrical signal is obtained without using any current from the power supply, the power that was conventionally consumed for position detection is no longer needed, which not only saves power, but also allows position detection even when the power is cut off. can.

In the following second to fourth figures, the same reference numerals as in FIG. 1 indicate the same members.

FIG. 2 shows a circuit in which a capacitor 01 is connected in parallel to the resistor R1 shown in FIG. 1a, and the differential waveform electric signal obtained in FIG. 1a is given a time constant and waveform shaped at the same time.

The differential waveform electrical signal obtained between terminals 6 and 7 is similar to that shown in FIG.

Note that the waveform obtained between terminals 7 and 11 is also similar to that shown in FIG. 5, but is much smaller than the differential waveform electric signal obtained between terminals 6 and 7.

In FIG. 3, a coil L1 is inserted in place of the resistor R1 shown in FIG. 1a, and the differential waveform electrical signal obtained in FIG. 1a is larger than the differential waveform electrical signal obtained in FIG. 1a.

In FIG. 4, a transformer T is inserted in place of the coil L1 shown in FIG. 3, and a differential waveform electric signal larger than the differential waveform electric signal obtained in FIG.
More can be obtained.

FIG. 6 is a rotation speed detection circuit diagram as an embodiment using the rotation angle phase detection device according to the present invention.

Symbols R2, R3...R9 are resistances, symbol C
2゜C3...C51 capacitor, MTr1tTr2, Tr3. indicate transistors, respectively.

The block circuit M1 includes a transistor Tri.

Tr2. This is a monostable multi-bibreak using .

By connecting the collector of Tr'l of monostable multi-bi break-Ml to the base of transistor Tr 3 and grounding the emitter of said transistor Tr 3 through resistor R7, monostable multi-bi break-M
An amplification circuit A is provided to amplify the output of l.

The emitter of transistor Tr 3, which is the output end of amplifier circuit A, is connected to resistors R8 and R9 and capacitors C4 and C5.
A smoothing circuit H is provided for smoothing.

Now, by inputting to the terminal 14 a differential waveform electrical signal as shown in FIG. 5 obtained from the rotational angle phase detection device according to the present invention, the monostable multi-bibreak-Ml is operated.

Monostable multibibreak-Ml is a differential electrical signal of 1
It operates only for a certain period of time in response to a pulse, and its output is obtained from the collector of the transistor Tr2.

The output of the transistor Tr2 is amplified by an amplifying circuit A, and converted into a voltage by a smoothing circuit H.

Therefore, the greater the number of pulses of the differential electric signal at the terminal 14, the higher the voltage at the output terminal 15 of the smoothing circuit proportionally becomes, and the rotational speed of the DC motor 5 is expressed as a voltage.

Therefore, by adding the rotation angle phase detection device of the present invention to the circuit shown in Figure 6, it is possible to detect the rotation speed of a DC motor with a simple configuration without using any other additional circuits such as a differential circuit. can.

FIG. 7 is a control circuit diagram of a DC motor as one embodiment equipped with the rotation angle phase detection device of the present invention.

Although a DC motor has good starting characteristics and good efficiency, it is difficult to control the rotational speed.

However, according to the control circuit for the DC motor according to the embodiment shown in FIG. 7, the motor follows the changing frequency and rotates synchronously.

In addition, symbols R10, R11......R26 are resistors, symbols c6°C7......C11 are capacitors, symbols Tr4°Tr5......Tr
9 represents a transistor, and symbols D2 and D3 represent a diode.

Resistor 22, Zener diode ZD, capacitor C1
1 is for stabilizing the power supply.

Astable multi-by-break - Ml is the transistor T
It is composed of r4, Tr 5, resistors R1O, R11, R12 and capacitors C6 and C7, and oscillates a square wave.

The differentiating circuit B is constituted by a capacitor C8 and a resistor R13, and transmits the square wave oscillated from the above-mentioned astable multi-by break-M1 as a differential waveform to the bi-stable multi-by break-M3.

Bistable multi-bibreak - M3 is transistor T
r7. Tr8, resistance R16゜R17, RlB, R25,
It is composed of capacitors C9 and C10, and the signal oscillated from the astable multi-vibration brake M2 is connected to the DC motor 5.
As an external synchronization signal for the bistable multi-by-break-M
Turn on transistor Tr7 by inputting to
, turns off the l-run sister Tr8.

Therefore, the transistor Tr9 is turned on, and the DC motor 5 is turned on.
to supply power.

As the DC motor 5 rotates, a differential waveform electric signal obtained by the rotation angle phase detection device according to the present invention is inputted to the bistable multi-by-break-M3, thereby turning off the transistor Tr7 and turning on the l-range screen Tr9. do.

Therefore, the transistor Tr9 is turned off and the power supplied to the DC motor 5 is cut.

Next, when the signal oscillated from the astable multi-by break-M2 is input to the bi-stable multi-by break-M3, the same process as described above is repeated cyclically.

The additional circuit F of the bistable multi-bibreak-M3 is the circuit M1. shown in FIG. This is a circuit controlled by A and H.

Circuit M1. The function of A and H is to detect the rotational speed as explained in FIG.

The bistable multi-by-break-M3 of this embodiment is configured such that the transistor Tr7 is always turned on or the transistor Tr8 is always turned on by the adder circuit F, or the transistor Tr7. Control can be performed in three cases where Tr8 is inverted.

Such control can eliminate the beat phenomenon that tends to occur when synchronously controlling DC motors.

As described above, by using the rotational angle phase detection device for a DC motor according to the present invention, the rotational angle phase can be detected not only with a completely simple circuit configuration without changing the configuration of the DC motor, but also with the present invention. By using the invented device, it is also possible to detect the rotational speed of a DC motor.

In addition, by using the device of the present invention, a DC motor that has good starting characteristics and efficiency can be rotated according to the frequency like a synchronous motor, and can follow the changing frequency and rotate synchronously. As mentioned above, this has an excellent effect in that it can be obtained without changing the structure of the DC motor at all.

[Brief explanation of drawings]

Figures 1 to 4 show the implementation of the rotational angle phase detection device for a DC motor, which is the device of the present invention. Examples using the apparatus are shown below. 1...Rotating shaft, 2-1.3-1...Brush, 5...DC motor, 4...Bearing,
2, 3, 6, 7, 8゜9.12, 13... terminal, 10-1.10-2゜10-3... commutator,
R1, R2...R26...Resistor, ZD...Zener diode, Dl. D2. D3...Diode, C1, C2...
・・・・・・C12・・・・Capacitor, Tr
1t Tr 2......Tr9...
Transistor, Ll... Coil, T...
・Transformer, Ml... Monostable multi-vi break-1 M2... Astable multi-bi break-1
M5... Bistable multi-bi break-1H...
... Smoothing circuit, A ... Amplifying circuit, B ...
... Differential circuit, F... Sign addition circuit.

Claims (1)

[Claims] 1. A DC motor equipped with a commutator and brushes, consisting of an electrical circuit in which a diode and an impedance element connected in reverse to the DC power supply are inserted, and an output terminal led out from both ends of the impedance element, and an adjacent When the brushes short-circuit the commutator pieces, the impedance of the armature coil changes, so the electromagnetic energy accumulated in the inductance of the armature coil is extracted as an electrical signal via the impedance element and the diode, and the rotor A rotation angle phase detection device for a DC motor, which is characterized by obtaining an angular phase detection signal.