JPH03276016A - Magnetic encoder - Google Patents

Abstract

PURPOSE:To enable a long distance transmission and to improve a noise resistance by incorporating a power supply for encoder and optically transmitting an output pulse. CONSTITUTION:When a motor 1 rotates, a generation of electric power is started by an AC generator 12 to supply the power to a stabilized power supply 13. In the case the motor 1 does not rotate, the power is supplied from a battery 14. The output pulse of encoder 16 is converted to light by a photoelectric converter 15 and inputted to a motor control device 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic encoder that detects rotational or linear displacement of an object to be detected.

[Conventional technology]

Figure 4 shows, for example, the Mechatronics Sensor Utilization Handbook (
It is a perspective view showing a schematic structure of a magnetic encoder shown in CQ Publishing Co., Ltd. P186-187.

In the figure, (1) is a motor of the object to be detected, (2) is a magnetic sensor, (3) is a disk whose magnetic poles N and S are mutually magnetized, and (4) is a waveform shaping circuit. Further, FIG. 5 shows a configuration diagram of a magnetic encoder. In the figure, (5) is a stabilized power supply, (6) is an output circuit, (7) is a magnetic encoder, (8) is an external DC power supply for use as a power source for the encoder (7), and (9) is a Pulse receiving circuit (101 is a motor control device, θυ is a coupling.

Next, the operation will be explained. Motor (1) shown in Figure 4
When the disk (3) rotates, the disk (3) rotates. When the disc (3) rotates, the resistance of the magnetoresistive element (2) changes due to changes in the magnetic poles N and S magnetized on its surface. The change is the 6th
The output is a sinusoidal waveform as shown in the figure fat.

The output is converted into a waveform by the waveform shaping circuit (5) in Figure 6 (b).
It is shaped into a rectangular wave as shown in 1 and output. Furthermore, when explained based on the configuration diagram of the magnetic encoder shown in FIG.
Power is supplied to the encoder (7) from an external power supply device (8) of the motor control device OG for controlling the electric motor (1). The stabilized power supply (5) of the magnetic encoder (7) generates the power used within the encoder (7) from the power supplied from the power supply (8). For example, if the output of the power supply device (8) is +24V, the power supply device (5) generates +5V from this +24V. Electrical components within the encoder (7) are supplied with power by this stabilized power supply (5). In terms of operation, as described above, the waveform shaping circuit (4) operates as shown in FIG.
It is transmitted from the output circuit (6) to the receiving circuit of the motor control device GO+ as a rectangular wave signal shown in FIG. Electric motor control device 0ω
By calculating the number of pulses of this signal, the electric motor (
1) The amount of rotational displacement can be detected and used for motor control. However, the waveform of the transmission between the output circuit (6) and the reception circuit (9) is as shown in Figure 6 (C) due to the capacitance of the electric wire due to electrical transmission.
As shown in the figure, the rising and falling edges are blunted, and the transmission distance is limited.

[Problem to be solved by the invention]

Since the conventional magnetic encoder is configured as described above, there are problems such as the inability to increase the transmission distance.

This invention was made to solve the above-mentioned problems, and its purpose is to obtain a magnetic encoder capable of long-distance transmission.

[Means to solve the problem]

The magnetic encoder according to the present invention uses optical transmission for output and has a power supply circuit inside.

[For production]

The magnetic encoder according to the present invention enables long-distance transmission by optical transmission and also improves noise resistance.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
In the figure, the same reference numerals as in Figure 5 indicate the same things, and 02
) is a generator connected to the rotating shaft of the magnetic pole disk (3), for example an alternating current generator, u3 is a stabilized power supply including a rectifier circuit, α→
Q51 is a battery, Q51 is a photoelectric converter, Q51 is a magnetic encoder according to the present invention, (171 is a receiving circuit that receives the optical output from the photoelectric converter (151), and an α-pulling motor control device.

The operation of this embodiment will be explained below.

When the electric motor (1) rotates, the alternator 0 starts generating power and supplies power to the stabilized power supply αJ. When the electric motor 5(1) does not rotate, power is not supplied by power generation and is supplied from the battery 04). This stabilized power supply 03 covers the power inside the encoder α, and is not supplied from the outside.

Encodaro6. The output pulse of the photoelectric converter (15+
The light is converted into light, transmitted to the receiving circuit (171), and input to the motor control device field.

Other pulse generation operations are the same as conventional ones.

The battery 04I is charged using the surplus power of the AC motor α○ via the stabilized power supply a3.

Further, a superconducting coil device may be provided in place of the battery 0 to provide the same function as the battery. In this case, power is supplemented to the superconducting coil by using surplus power from the alternator α2) via the stabilized power supply (13).

Furthermore, a DC generator may be provided in place of the AC generator (12), and even when the DC generator is used, the battery is zero.
It goes without saying that the above-mentioned superelectric coil device may be provided in place of the gradient, and the same effects as in the above embodiment can be achieved. When a DC generator is used, the stabilized power supply α3 does not include a rectifier circuit but includes a voltage dividing circuit.

FIG. 2 shows another embodiment of the present invention, in which 09+ is a stabilized power supply including a voltage dividing circuit, 09+ is a solar cell connected to the stabilized power supply [131], and (20) is a solar cell connected to the stabilized power supply [131]. In the magnetic encoder according to the present invention, other symbols indicate the same ones as in FIG.

The operation of this embodiment will be explained below.

Power is supplied from the solar cell (191 to stabilized power supply port 3), and this stabilized power supply f131 powers the encoder (20).
It covers the internal power supply and does not receive power from outside.

The output pulses of the encoder (4) are converted into light by a photoelectric converter, transmitted to a receiving circuit (17), and input to a motor control device.

FIG. 3 shows another embodiment of the present invention, in which one battery similar to that in FIG. 1 is provided in the structure shown in FIG. The encoder shown in FIG. 2 is the same as that shown in FIG.

The operation of this embodiment will be explained below.

This encoder supplies power to the stabilized power supply GJ using the power generated by the solar cell Q91. Since a power shortage may occur if the outside light is weak, a battery 04 is built in as a backup, and when the output of the solar battery decreases, power is supplied from the battery α to the stabilized power supply αa. This stabilized power supply 1131 supplies the encoder (within 2 watts of power) and is not supplied from outside.

The output pulse of the encoder (211) is output from the photoelectric converter Q51.
The signal is converted into light by the receiver circuit (17+) and input to the motor control device 08.

Other pulse generation operations are the same as conventional ones.

The batteries (1 to 1) are charged using the surplus power of the solar cells (19+) via the stabilized power source (131).

Further, in the above embodiment, a superconducting coil device may be provided in place of the battery 04) to provide the same function as the battery. In this case, power is replenished to the superconducting coil by using the surplus power of the sum of the power supply α and the power supply through the stabilized power supply port a.

Note that in each of the above embodiments, the detection section is configured using a magnetoresistive element, but even if the detection section is configured using other materials, the same effects as in the above embodiments can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, since the encoder power supply is built-in and the output pulses are transmitted optically, long-distance transmission is possible and a product with high noise resistance can be obtained. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a magnetic encoder according to an embodiment of the present invention, FIGS. 2 and 3 are block diagrams showing other embodiments of the invention, and FIG. 4 is a block diagram showing a conventional magnetic encoder. A perspective view, FIG. 5 is a block diagram of a conventional encoder, and FIG. 6 is an output waveform diagram of each part in FIG. In the figure, (2) is a magnetic sensor, (3) is a magnetic pole disk, (4)
is a waveform shaping circuit, α is a generator, t13) is a stabilized power supply, 0 slope is a battery, (151 is a photoelectric converter, (191 is a solar cell, (161 (a) c!11 is a magnetic encoder In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A magnetic encoder having a signal detection system that magnetically generates a pulse signal and detects the signal, characterized by having a built-in self-sufficient power source and a photoelectric converter that outputs an external output as light. Magnetic encoder.