JPS58153437A - Device for transmitting signal - Google Patents

Abstract

PURPOSE:To transmit signals between plural devices to be controlled and a controlling device to control these devices by using a photocoupling means for the signal transmission, and also using a two-core cable for a signal line to connect both the devices. CONSTITUTION:A signal transmission/reception part 41 on the controlling device side is set up in the transmission mode and a signal to be transmitted is inputted to the base of a transistor (TR) 48. Voltage supplied from a reference voltage supplying terminal 45 is supplied to a light emitting element 65 and a diode 70 in a signal transmission/reception part 42 on the air conditioner side through a current limiting resistor 51, a diode 52 and a signal line 43 and then applied to the collector of the TR 48 and a circuit consisting of the emitter of the TR 48, a diode 55 and a TR 47, so that a light emitting element 65 in a signal transmission/reception part 42 on the air conditioner side is driven. Consequently a receiving signal is generated on the emitter side of a photodetector 66.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal transmission device using a photocoupler, and is capable of electrically transmitting signals between a plurality of controlled devices and a control device that controls the plurality of controlled devices. The signal line connecting the plurality of controlled devices and the control device described above is realized using a two-core cable. be.

In general, when signal transmission is performed using electrical energy as a signal, noise is likely to occur between the common potentials of two or more separated devices, so there is a need to prevent malfunctions, and there is a need to prevent malfunctions between a control device and multiple controlled devices. When transmitting signals between them, there were complications, such as the need to suppress the noise emitted from each, and to create a signal with the electrical energy necessary to reliably transmit the signal.

For example, a conventional signal transmission device for controlling the operation of an air conditioner will be explained with reference to Fig. 1. In Fig. 1, 1 is an indoor unit of a separate air conditioner;
is an outdoor unit, in which the compressor 3, indoor heat exchanger 4, pressure reducing device 6, and outdoor heat exchanger 6 are connected to outdoor connecting pipes 7, 8.
etc., to form a refrigeration cycle. 9 is an indoor fan, and 10 is an outdoor fan. In this separate air conditioner, the following two types of information are mainly transmitted from the indoor unit 1 side to the outdoor unit 2 side. The first information is an operation ψ stop command for the compressor 3, which is the compressor control electrical signal section 11.
is transmitted to the compressor control unit 13 via the electrical conductor line 12. The second information is a strength switching command for the outdoor fan 1o, which is transmitted from the outdoor fan control electrical signal section 14 to the outdoor fan switching control section 16 via the electrical conductor wire 15. On the other hand, from outdoor unit 2 to indoor unit 1
The information transmitted to the electric conductor 1 is the value detected by the outside temperature □ detection element 17 from the outside temperature electrical signal section 18.
9, the outside temperature signal is transmitted to the outside temperature signal receiving section 20. In this way, since the means for mutually transmitting information between the indoor and outdoor units 7) 1 and 2 uses electrical energy as a signal source, noise is particularly likely to occur between the common potentials of the two separated units. For this reason, there are drawbacks such as the need to take complicated measures to prevent malfunctions due to noise signals and to suppress noise emitted from the indoor and outdoor units 1 and 2, respectively.

Therefore, in the past, as a means to eliminate the above drawback, the method shown in Fig. 2'
As shown in Figure 2, a signal transmission device using photocoupler coupling was considered. That is, in this Figure 2, 2
1 is a signal transmitting/receiving section on the control device side, 22 is a signal transmitting/receiving section on the controlled device side, 23.24 is a reference voltage supply terminal, 25.
26 is a switching element for driving a transmission signal, 27.28 is a receiving terminal resistor, 29.30 is a photocoupler composed of a light emitting element 31.32 and a light receiving element 33.34, 35
36 is a current control resistor, and 37.38 and 39.40 are transmission lines.

As is well known, signal transmission in this configuration is performed by the control device 21
．． Light receiving element 33.3 in the signal transmitting and receiving unit on the controlled device 2 side
4, a light emitting element 31, which is driven by the corresponding device, respectively.
This is made possible by adopting a configuration in which 32 are optically coupled to each other.

However, as seen in the figure, both the devices 21
．． At least four transmission lines 3 for signal transmission and reception between 22
7, 38, 39, and 40, which is not economical.

The present invention solves these conventional drawbacks. In particular, it eliminates the common potential between the two separated devices, prevents malfunctions due to noise, and connects the devices with two transmission lines. This paper proposes a method for signal transmission.

A signal transmission device according to an embodiment of the present invention will be described below with reference to FIG. 3 of the accompanying drawings.

In FIG. 3, 41 indicates a signal transmitting/receiving section on the control equipment side, and 42 indicates a signal transmitting/receiving section on the controlled equipment side, such as an air conditioner. Reference numerals 43 and 44 indicate signal lines connecting the signal transmitting units provided in both the devices.

Note that since the present invention is directed to a signal transmission method, a description regarding control of a refrigeration cycle of an air conditioner will be omitted. Signal transmitting/receiving section 41 on the control equipment side
46 is a reference voltage supply terminal, 46.47.4
8.49 is a switching element, 6o is a bias resistor, 5
1 is a current limiting resistor, 52, 53, 54, and 5 are switching diodes, 66 is a terminating resistor, 67 is a diode for reverse voltage protection of the switching element 56, and 58.
59 is a noise prevention capacitor, 60 is an inverter circuit for signal inversion, 61 is a reception terminal, 62 is a signal transmission/reception switching input terminal, 63 is a transmission signal input terminal, and the capacitors 58 and 69 are connected to signal lines 43 and 44. This is for removing the noise above.

On the other hand, the signal transmission/reception unit 42 on the side of controlled equipment such as an air conditioner
, 64 is a photocoupler, which is composed of a light emitting element 66 and a light receiving element 66. 67 is a photocoupler, and the light emitting element 6
8 and a light receiving element 69.

70.71 is a reverse current prevention diode, 72 is a switching element, 73 is a reference voltage supply terminal, 74 is a terminating resistor, 7
5 is a reception terminal, 76 is a current limiting resistor, and 77 is a transmission signal input terminal.

The signal transmission device of the present invention is capable of two-wire half-duplex communication. First, the signal transmitter/receiver section 4 on the control equipment side
The signal sent from 1 is sent to the signal transmitting/receiving unit 4 on the air conditioner side.
2, the receiving mode will be explained.

Directional control of signal transmission and reception in this embodiment is provided by the signal transmission and reception section 41 on the control equipment side.

By the signal supplied from the signal transmission/reception switching input terminal 62 in the same figure, that is, by leading the switching element 49 to non-conduction and by leading the switching element 47 to conduction via the inverter circuit 6o, the signal on the control equipment side The transmitter/receiver 41 will be set to transmit mode.

In this mode, when a signal to be transmitted, such as a pulse signal or a 7-narok signal, is supplied to the switching element 48, for example, the base of a transistor, in order to drive the switching element 48 to the transmission signal input terminal, the reference voltage supply terminal 46 The voltage supplied from the current limiting resistor 61. Switching diode 52. Then, a signal transmission/reception unit 42 on the air conditioner side via a signal line 43
After passing through the light emitting element 66 and the backflow prevention diode To, the signal transmitting/receiving section 4 on the control device side passes through the signal line 44 again.
1 to the collector of a switching element 48, for example a transistor, and to the switching element 48, for example the emitter of a transistor, a switching diode 6
5. Since the voltage is applied to the switching element 47, for example, a circuit made of a transistor, the light emitting element 66 in the signal transmitting/receiving section 4/2 on the air conditioner side is driven. As a result, a reception output is induced on the emitter side of the light receiving element 66.

Next, a mode in which a signal sent from the signal transmitting/receiving section 42 on the air conditioner side is received by the signal transmitting/receiving section 41 on the control equipment side will be described.

In this case, the signal supplied from the signal transmission/reception switching input terminal 62 of the signal transmission/reception unit 41 on the control equipment side is used, that is, the switching element 49 is brought into conduction, and the switching element 49 is connected via the inverter circuit 6o. 47
By making it non-conductive, the signal transmitting/receiving section 41 on the control device side is set to the receiving mode.

In this mode, the voltage supplied from the reference voltage supply terminal 46 is transmitted through the switching element 46, the switching diode 57, and the signal line 44 to the light receiving element 69. The backflow prevention diode 71, and then again via the signal line 43, the terminating resistor 66 in the signal transmitting/receiving section 41 on the control device side, and the switching diode 53. It is applied to the circuit through switching element 49 and to ground.

Therefore, the light emitting element 6 in the signal transmitting/receiving section 42 on the air conditioner side
A switching element 72 provided to drive 8
, the transmission signal input terminal 77 by, for example, a transistor.
When the switching element is driven by a signal inputted from the control device, a reception output is induced to the reception terminal 61 in the signal transmission/reception section 41 on the control equipment side.

As is clear from the above configuration, according to this embodiment, the control equipment and the controlled equipment such as the air conditioner can be electrically separated. O) It is not affected by the noise that occurs when it is OFF. In addition, signal lines 43 and 44 that connect the transmitter/receiver 41 on the control device side and the transmitter/receiver 42 on the controlled device side
wire breakage can be easily detected. That is, when the transmitting/receiving section 41 on the control device side is set to the transmitting mode and a signal is supplied from the transmitting signal input terminal 63, the switching elements 47 and 48 are connected to the receiving terminal 61. Voltage X2 )+(
Forward voltage drop voltage of reverse current prevention diode 70) + (
The forward voltage of the light emitting element 66 (forward voltage of the light emitting element 66) will be lower than the reference voltage until the voltage level is the sum of the voltages, but by detecting this voltage drop, disconnection of the signal lines 43 and 44 can be detected. is possible. Furthermore, when transmitting signals to multiple controlled devices, the signal to be transmitted is pulse encoded, and address information corresponding to at least each controlled device is added to this pulse encoded signal. It becomes possible to communicate with many controlled devices.

, As is clear from the description of the above embodiments, the present invention 1
The signal transmission device includes a first connection body in which a first light emitting means and a first light receiving means are connected in antiparallel, and a light emitting current limiting resistor, a first switching means, and a second switching means. A second connecting body is provided between a reference voltage and a contact surface in order to cause the first light emitting means to emit light, and a second connecting body is provided that is connected to the first connecting body so as to cause a current to flow through the first light receiving means. A third connecting body is provided in which a voltage is grounded via the third switching means and a current limiting resistor, and a fourth switching means is operated to alternately operate the first switching means and the third switching means. provided with a switching means for
a second light receiving means for detecting the light from the first light emitting means;
Since the second light emitting means for irradiating light to the first light receiving means is provided, even if noise or the like occurs at 077 when the equipment controlled by the signal sent by this signal transmission device is turned on, It is possible to accurately transmit signals without being affected by these noises, and there is no need for malfunction prevention devices or miscellaneous occurrence suppression devices that have conventional complex configurations. The purpose can be achieved, and furthermore, there are effects such as being able to easily detect the breakage of the signal transmission conductive wire.

[Brief explanation of drawings]

FIG. 1 is a schematic electrical circuit diagram of an air conditioner equipped with a conventional signal transmission device, FIG. 2 is an electrical circuit diagram showing another conventional signal transmission device, and FIG. 3 is a signal transmission diagram according to an embodiment of the present invention. FIG. 3 is an electrical circuit diagram of the transmission device. 41...Signal transmitting/receiving section on the control equipment side, 42...
...Signal transmission and reception section on the controlled equipment side, 46...
・Reference voltage supply terminal, 46, 47, 48, 49...
...Switching element, 50.51...Bias resistor, 62゜53.64,56...Switching diode -66...Terminal resistor, 66...
... Light emitting element, 66 ... Light receiving element, 68
... Light emitting element, 69 ... Light receiving element, 7
2...Switching element, 73...Reference voltage supply terminal, 74...Terminal resistor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
! l Figure 2

Claims (1)

[Claims] A first connection body is provided in which the first light emitting means and the first light receiving means are connected in antiparallel, and the light emitting current limiting resistor, the first switching means, and the second switching means are connected to the first light emitting means. A second connecting body configured by connecting between a reference voltage and ground to emit light is provided, and with respect to the first connecting body,
A reference voltage is set so that a current can flow through the first light receiving means,
A fourth switching device includes a third connecting body that is grounded via the third switching device and a current limiting resistor, and operates to alternately operate the first switching device and the third switching device. A signal transmission device comprising: a second light-receiving means for detecting light from the first light-emitting means; and a second light-emitting means for irradiating light to the first light-receiving means.