JPH01261000A - Two-way communication circuit - Google Patents

Abstract

PURPOSE:To avoid mis-wiring at grounding of a signal wire by connecting one terminal of a 2nd switching element turned of/off in interlocking with a 1st switching element to a 2nd terminal and connecting the other terminal to a ground terminal so as to make the polarity of the signal connected to the 1st and 2nd terminals ineffective. CONSTITUTION:An AC input terminal is connected to a 1st terminal and a 2nd terminal respectively in a single phase diode bridge comprising plural rectifier diodes and the DC terminal (+) is connected to a base of a transistor(TR) 2 and a ground terminal (-) is connected to a ground level. Moreover, the collector of the TR 2 is connected to an output terminal RXD of the reception signal. In the 2-way communication circuit constituted in this way, the signal given to the 1st and 2nd terminals is passed through the diode bridge 1, then the signal is outputted from the DC terminal (+) of the diode bridge to the TR 2 independently of the polarity of the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of industrial application The present invention transmits and receives signals between a plurality of devices using a first terminal and a second terminal.
This relates to a bidirectional communication circuit that uses a common signal line connected to a terminal.

(b) Conventional technology In general, as a conventional communication circuit, the Japanese Patent Publication No. 59-30973
There was something like the one described in the publication. What is described in this publication connects the indoor unit controller and outdoor unit controller of an air conditioner with a pair of signal wires, and uses one as a signal wire and the other as a ground wire to transmit signals between these units. It was used for sending and receiving.

C) Problems to be Solved by the Invention In such conventional technology, a pair of signal lines has polarity for signal and ground, and incorrect wiring may occur when the signal line is grounded. Ta.

In view of such problems, the present invention provides a bidirectional communication circuit in which the connection polarity of the signal lines on the input side and the output side can be made non-polar.

(d) Means for Solving the Problems The bidirectional communication circuit of the present invention connects AC input terminals of a diode bridge including a plurality of rectifying diodes to first terminals,
The positive output terminal of this diode bridge is connected to the output terminal of the received signal, and the high level voltage or low
One terminal of a first switching element that turns ON10 F F in response to a level voltage transmission signal is connected to a power supply terminal, the other terminal is connected to the first terminal, and the first switching element turns ON10 F in conjunction with the first switching element. One terminal of the second switching element that performs FF is connected to the second terminal, and the other terminal is connected to the ground terminal.

(f) Function The communication circuit configured as described above applies signals from other devices to the AC input terminal of the diode bridge, so
Signal lines can be connected regardless of connection polarity. Also number 1. By using the second switching element, the output signal can be superimposed on this signal line.

(f) Examples Examples of the present invention will now be described based on the drawings. FIG. 1 is an electronic circuit diagram of an embodiment. In the figure, 1 is a single-phase diode bridge consisting of a plurality of rectifier diodes, and the AC input terminals (~) are connected to the first terminal and the second terminal, respectively.
The DC terminal (+) is connected to the base terminal of the transistor 2, and the ground terminal (-) is fully connected to the ground level. Further, the collector terminal of the transistor 2 is connected to the output terminal RXD of the received signal. The transistor 3 has a base terminal connected to the transmission signal input terminal TXD, and an emitter terminal connected to the first terminal A. The transistor 4 has its base terminal connected to the input terminal TXD, and its collector terminal connected to the second terminal B.

In the bidirectional communication circuit configured in this way, the first terminal,
The signal applied to the second terminal passes through the diode bridge 1, regardless of the polarity of the signal, and the signal is transferred from the DC terminal (+) of the diode bridge 1 to the transistor 2.
Output to. In addition, the transistors 3 and 4 are
is ON/OFF at the same time, transistor 3.4 is ON
1, an H level voltage signal can be output between the first terminal A and the second terminal B.

FIG. 2 is a specific circuit diagram of a two-way communication circuit used for transmitting and receiving signals between a plurality of devices 5, 6, and 7. For example, in the device 5, a diode bridge 8, transistors 9, 10 .
Reference numerals 11 correspond to the diode bridge 1 and transistors 2, 3.4 shown in FIG. 14 is a positive characteristic thermistor, and signal line 1
5. When the current flowing between 16 and 17. This is to cut off the connection with the two-way communication circuit.

Note that the devices 6 and 7 also have a bidirectional communication circuit similar to that of the device 5.

In the bidirectional communication circuit configured as described above, the respective devices 5, 6, and 7 are connected in the same manner as in the bidirectional communication circuit shown in FIG.
Signals can be sent and received arbitrarily between the two.

(G) Effects of the Invention The two-way communication circuit of the present invention connects the AC input terminals of a diode bridge including a plurality of rectifying diodes to the first terminal,
The positive output terminal of this diode bridge is connected to the output terminal of the received signal, and the high level voltage or low
One terminal of a first switching element that turns ON10FF in response to a level voltage transmission signal is connected to a power supply terminal, the other terminal is connected to the first terminal, and the first switching element turns ON in conjunction with the first switching element. Since one terminal of the second switching element to be turned off is connected to the second terminal and the other terminal is connected to the ground terminal, the first. The polarity of the signal that can be connected to the second terminal can be made non-polar. At the same time, the first. Signals can be sent and received through a pair of signal lines connected to the second terminal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electronic circuit diagram showing an embodiment of the present invention, and FIG. 2 is an electronic circuit diagram showing a state in which the circuit of the present invention is used in three devices. 1... Diode bridge, 2, 3.4... Transistor, A... First terminal, B... Second terminal, RXD... Output terminal.

Claims (1)

[Claims] (1) Connect the AC input terminals of a diode bridge consisting of a plurality of rectifier diodes to the first terminal and the second terminal, respectively,
The positive output terminal of this diode bridge is connected to the output terminal of the received signal, and one terminal of the first switching element that is turned on/off in response to the transmitted signal of H level voltage or L level voltage is connected to the power supply terminal, Connect the other terminal to the first terminal and turn ON/OFF in conjunction with the first switching element.
One terminal of the second switching element to be turned off is connected to the second
A two-way communication circuit characterized in that one terminal is connected to one terminal and the other terminal is connected to a ground terminal.