KR920006209Y1 - Telephone lines sensing circuit - Google Patents

Abstract

No content.

Description

Telephone line condition detection circuit in scanner type wind system

1 is a conventional white.

2 is a circuit diagram according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: exchanger 30: line voltage detection unit

40: line state detection unit 50: system control and communication unit

60: terminal 70: telephone

BR1: Borage Diode

The present invention relates to a scanner type system for providing a remote service using a telephone network, and more particularly to a circuit for detecting a line state by checking the state of the telephone line.

FIG. 1 is a conventional circuit diagram. When the telephone 10 is not used while the relay RY1 is turned on under the control of the system control and communication unit 50, the voltage supplied from the switch 10 to the telephone is bridged. It is applied to the diode BD1. At this time, since the voltage of -48 is applied when the phone 70 is not used, the bridge diode BD1 is polarized and outputted.

When the voltage output from the bridge diode BD1 passes through the zener diode ZD1 through the resistor R2, the transistor Q1 is turned on. When the transistor Q1 is turned on, the potential of the collector is lowered, so the transistor Q2 is turned off.

When the transistor Q2 is turned off, the optocoupler U1 is not operated and a high state is output to the line 102.

In addition, when the relay RY1 is turned on under the control of the system control and communication unit 50 and the telephone 70 is used, the zener diode ZD1 is turned off, so the transistor Q1 is turned off.

When the transistor Q1 is turned off, the collector potential rises, so the transistor Q2 is turned on. When the transistor Q2 is turned on, the optocoupler U1 is driven to output a low signal to the line 102.

However, a high signal is output to the line 102 even when the relay RY1 is turned off.

The conventional circuit as described above does not use the telephone when the relay RY1 is on or the output is the same when the relay RY1 is off. It is not possible to determine whether the terminal is not called due to the failure of) or the non-response due to the failure of the terminal, there may be an error when the service is performed, and noise is generated due to the instantaneous turn on of the transistor even during a call. .

Accordingly, an object of the present invention is to provide a circuit that can accurately detect a line state by checking a telephone line state so as to facilitate a terminal call, and to prevent noise due to a line access of a caller during a call.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a circuit diagram according to the present invention, a bridge diode (BR2) for inputting the output voltage of the exchanger 10, the exchanger 10 is aligned and outputted, the exchanger 10 and the bridge diode (BR1) A relay RY1 connected between the relay RY1 for switching the output of the interceptor 10, a terminal 60 and a telephone 70 connected in parallel between the switch 10 and the relay RY1, and the relay RY1; System control and communication unit (50) for controlling on-off switching of the < RTI ID = 0.0 >) < / RTI > and a call service of the terminal 60, and a positive (+) output terminal and a negative (-) output terminal of the bridge diode BR1. A line voltage detector 30 which detects a line voltage by connecting a resistor R2 and a zener diode ZD1 and a diode D1 in series, and the positive output terminal (+) of the bridge diode BR1 and a negative electrode. Between the polarity (-) output terminal, resistor (R3) and optocoupler (U1) light emitting diode (PD1) and transistor (FET1) ) Is connected in series, and the gate of the transistor FET1 is connected to the output line of the line voltage detector 30, and the collector of the light receiving transistor PT1 of the optocouple U1 is connected to the system control and communication unit 50. And a line sensing controller 40 for controlling to detect a line state by the output voltage of the line voltage detector 30.

Based on the above-described configuration will be described the present invention in detail.

When the relay RY1 is turned on by the system control and the communication unit 50, the voltage supplied from the exchanger 10 is applied to the bridge diode BR1.

At this time, since the voltage of -48 is applied when the phone 70 is not used, the bridge diode BR1 is polarized and outputted. The voltage output from the bridge diode BR1 passes through the zener diode ZD1 through the resistor R2 and the transistor FET1 is turned on. When the transistor FET1 is turned on, the optocoupler U1 is driven to output a low signal through the line 102. In addition, when the relay RY1 is on and the telephone 70 is in use, the zener diode ZD1 is turned off, so the transistor FET1 is turned off. When the transistor FET1 is turned off, the optocoupler U1 is not driven, thereby outputting a high signal to the line 102. In the state where the telephone 70 is used, the optocoupler U1 is not driven so that electrical noise is not applied to the line during the call, and thus does not affect the call.

Therefore, the system control and communication unit 50 checks the state of the line after turning on the relay RY1 and checks the state of the line. If the signal output to the line 102 is kept high for a predetermined time during the call, the relay RY1 Off).

If the telephone 70 is not in a call, the terminal 60 is called through the system control and communication unit 50 only when the signal output to the line 102 is turned low after the relay RY1 is turned on. Thus, the defective state of the terminal 60 can be accurately determined.

At this time, the terminal 60 performs various services by connecting various kinds of home meters or alarm sensors.

As described above, the terminal can be easily called by checking the telephone line, and there is an advantage of removing noise due to line access during the call.

Claims (1)

The exchanger 10 and the bridge diode BR1 for inputting the output voltage of the exchanger 10 and sorting the polarity thereof are then connected between the exchanger 10 and the bridge diode BR1 and connected to each other. A relay RY1 for switching an output voltage, a terminal 60 and a telephone 70 connected in parallel between the exchanger 10 and the relay RY1, and on-off switching of the relay RY1; In a telephone line state sensing circuit of a scanner type remote service system having a system control unit and a communication unit 50 for providing a call service of the terminal 70, a positive output terminal of the bridge diode BR1 and a positive output terminal of the bridge diode BR1 are provided. A line voltage detector 30 which detects a line connection by connecting a resistor R2 and a zener diode ZD1 and a diode Dl in series between a negative output terminal and a positive polarity of the bridge diode BR1. Resistance (R3) between output terminal (+) and negative (-) output terminal And a light emitting diode PD1 of the optocoupler U1 and a transistor FET1 are connected in series, and a collector of the light receiving transistor PT1 of the optocoupler U1 is connected to the system control and communication unit 50. And a line sensing controller 40 connected to an output line of the line voltage detector 30 so as to control a state of the line by the output voltage of the line voltage detector 30. Circuit.