JP2010067024A - Relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To electrically separate a ground terminal of a power supply line from a common terminal of a signal line and save current consumption of the signal line. <P>SOLUTION: A relay 12 for radio reception is connected to each of the power supply line 20 that is pulled out of a receiver 10 and to which direct current power supply voltage is applied and the signal line 22 to which direct current circuit voltage is applied. A restoration detection circuit 40 of the relay 12 for radio reception includes an oscillating circuit for stopping oscillation of a pulse signal during restoration signal transmission of the receiver 10 that receives application of the direct current circuit voltage from the receiver to the signal line 20, intermittently oscillates pulse signals, and temporarily stops voltage application of a pair of signal lines. The pulse signals from the oscillating circuit are electrically separated and output by a photo coupler, transmission of a restoration signal from the receiver is discriminated by stop of the pulse signals, and restoration operation is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a relay device used in a wireless disaster prevention system that receives a fire signal wirelessly transmitted from a wireless sensor and relays it to a receiver connected to a signal line.

  Conventionally, in a wireless disaster prevention system that monitors fires, when a plurality of wireless sensors are installed in a warning area such as each floor of a building and a fire is detected by the wireless fire sensor, a wireless signal indicating the fire is sent. It is transmitted to the radio reception repeater installed in the floor unit. The relay device for wireless reception is connected to the detector line from the fire receiver. When a fire wireless signal is received, a fire alarm signal is generated by sending a notification current between the detection lines when the relay contact or switching element is turned on. Is sent to the receiver to issue a fire alarm.

  Also, if the distance from the wireless sensor to the wireless reception repeater is long, a radio wave repeater is installed on the way to relay and transmit the fire radio signal from the wireless sensor. Is not lost.

  According to such a wireless disaster prevention system, it is possible to eliminate the need for a sensor line for connecting the repeater installed on the floor of the building to the sensor, simplify the wiring work, and also require a place for the sensor to be installed. It can be determined accordingly.

  By the way, in the radio reception relay device of such a radio disaster prevention system, as shown in FIG. 11, the power supply line 104 drawn from the receiver 100 is connected to the power supply terminal V and the ground terminal of the radio reception relay device 102. The signal line 106 is connected to the line terminal L and the common terminal C of the wireless reception relay device 102. Since the reception repeater stands by in a state where radio signals can always be received, the current consumption is large and power cannot be taken from the LC line.

  The repeater circuit provided in the wireless reception repeater 102 operates upon receiving a predetermined DC power supply voltage from the power supply line 104. For example, DC 24 volts is applied as a predetermined line voltage from the receiver 100 to the signal line 106. When a fire signal is received from the wireless sensor, a switching circuit (not shown) is turned on and an alarm current is supplied to the signal line 106. Then, the alarm signal is transmitted to the receiver 100.

  Further, a recovery signal is transmitted from the receiver 100 to the wireless reception relay device 102 in accordance with a recovery operation or the like. The restoration signal is transmitted by temporarily stopping the applied voltage from the receiver 100 to the signal line 106.

  A conventional restoration signal detection circuit 108 shown in FIG. 11 includes a transistor Q1 and resistors R11 to R13. When DC 24 volts is normally applied to the signal line 106, the transistor Q1 is turned on under the bias of the resistors R11 and R12, and the output signal to the repeater circuit is L level logic.

When the voltage applied to the signal line 106 is temporarily stopped along with the restoration of the receiver 100, the transistor Q1 is turned off, and the restoration operation is performed with the output signal to the repeater circuit as the logic of H level.
JP-A-5-274580 JP 2001-290209 A

  However, in the restoration signal detection circuit 108 provided in such a conventional wireless reception relay device, the ground terminal GND of the power supply line 104 and the common terminal C of the signal line 106 are short-circuited inside the relay device and grounded. It is necessary to make the potentials of the terminal GND and the common terminal C coincide with each other, and there is a problem that it takes much time and labor to assemble and install. This is because if the ground terminal GND and the common terminal C are not short-circuited, a current due to the potential difference between the two flows in the repeater circuit, causing damage to the equipment.

  A circuit using a photocoupler is conceivable as a method of receiving a restoration signal without requiring such a short-circuit connection between the ground terminal GND and the common terminal C. FIG. 12 shows the restoration signal detection circuit 108 using the photocoupler 112.

  The restoration signal detection circuit 108 in FIG. 12 connects the light emitting element LED of the photocoupler 112 between the line terminal L and the common terminal C of the signal line 106 via the current limiting resistor R14, and DC 24 volts with respect to the signal line 106. Is applied to drive the light emitting element LED to emit light, the phototransistor PT is turned on by the light from the light emitting element LED, and an L level signal is output.

  When the applied voltage of the signal line 106 is temporarily stopped along with the recovery of the receiver 100, the light emission of the light emitting element LED is stopped, the phototransistor PT is turned off, and the capacitor C1 is charged through the resistor R15. A differential pulse signal that changes to a level is output and a recovery operation is performed.

  Thus, by providing the photocoupler 112 and electrically separating the signal line 106 side and the power supply line 104, it is possible to eliminate the need for short-circuit connection between the ground terminal GND and the common terminal C.

  However, in the restoration signal detection circuit 108 using the photocoupler 112, it is necessary to pass a relatively large current of several mA generally to the signal line 106 in order to drive the photocoupler 112. When a large current flows to drive the photocoupler 112 to the signal line 106 in this way, there is a possibility that the receiver 100 side erroneously determines that the alarm signal has been transmitted from the wireless reception relay device 102. Therefore, it is difficult to take a method of electrically separating with a photocoupler.

It is an object of the present invention to provide a wireless reception relay device that does not require a short-circuit connection between a ground terminal of a power supply line and a common terminal of a signal line and that requires less current consumption of the signal line.

The present invention provides a relay device connected to each of a pair of power lines drawn from a receiver and applied with a predetermined DC power supply voltage and a pair of signal lines applied with a predetermined DC line voltage.
Connected between a pair of signal lines, intermittently oscillates a pulse signal when a DC line voltage is applied, and suspends pulse signal oscillation when a recovery signal is transmitted to a receiver that temporarily stops voltage application of a pair of signal lines An oscillation circuit to
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
A repeater circuit that operates by supplying power from a pair of power lines, determines the transmission of the recovery signal from the receiver by stopping the pulse signal from the isolation circuit, and performs the recovery operation;
It is provided with.

In another embodiment of the present invention, each of the pair of power lines drawn from the receiver and applied with a predetermined DC power supply voltage is connected to each of the pair of signal lines applied with a predetermined DC line voltage. In the relay device
A capacitor connected between a pair of signal lines via a diode or resistor and charged to a DC line voltage;
An oscillation circuit that intermittently oscillates a pulse signal;
A switch circuit for supplying a capacitor charging voltage as a power supply voltage to the oscillation circuit;
Operates by receiving power supply from the capacitor. When it is detected that the applied voltage of the pair of signal lines is equal to or higher than the predetermined voltage, the switch circuit is turned off to stop the oscillation circuit, and when the restoration signal is transmitted from the receiver. A voltage detection circuit that turns on the switch circuit and intermittently oscillates the pulse signal by the operation of the oscillation circuit when detecting a voltage drop due to a temporary suspension of voltage application of the pair of signal lines;
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
A repeater circuit that operates by supplying power from a pair of power supply lines, determines a transmission of a recovery signal from a receiver by inputting a pulse signal from an isolation circuit, and performs a recovery operation;
It is provided with.

  Here, the isolation circuit is a photocoupler including a light emitting element driven to emit light by a pulse signal from an oscillation circuit and a phototransistor that is turned on by light from the light emitting element.

  The isolation circuit may be an amplifier in which the output of the oscillation circuit is input-connected through a DC cut capacitor.

The repeater circuit sends a notification signal to the receiver by causing a signal current to flow between a pair of signal lines when a wireless signal is transmitted from a wireless sensor that detects a fire and transmits a notification wireless signal. .

  According to the present invention, when a predetermined DC line voltage is applied to the signal line from the receiver, the oscillation circuit oscillates a pulse signal at regular intervals, and this pulse signal is input via the photocoupler. On the other hand, if the applied voltage of the signal line is temporarily stopped during the recovery signal transmission of the receiver, the pulse signal from the oscillation circuit stops and this can be detected and the recovery operation on the repeater side can be performed. It is not necessary to short-circuit the ground terminal GND of the power supply line and the common terminal C of the signal line by the isolation by the above, and at the same time, by setting the duty ratio of the pulse signal of the oscillation circuit that turns on the photocoupler to an appropriate value The current consumption flowing in the photocoupler can be greatly reduced.

In another embodiment of the present invention, when a predetermined DC line voltage is applied from the receiver to the signal line, the pulse signal from the oscillation circuit is stopped, while the receiver recovery signal When the applied voltage of the signal line is temporarily stopped during transmission, it is not necessary to short-circuit the ground terminal GND of the power line and the common terminal C of the signal line by outputting a pulse signal from the oscillation circuit, and at the same time, the applied voltage is Since the oscillation circuit outputs the pulse signal only during the transmission of the recovery signal that is temporarily stopped, the current consumption flowing through the photocoupler can be further reduced.

  FIG. 1 is an explanatory view showing a wireless disaster prevention system to which the present invention is applied. In FIG. 1, a P-type receiver 10 is installed as a fire receiver on the first floor of a building 11 to be monitored, and the transmission line 18 drawn from the P-type receiver 10 is relayed according to the present invention for each floor. A radio reception repeater 12 as a device is connected. The transmission line 18 includes a pair of power supply lines and a pair of signal lines.

  A wireless sensor 16 is installed on each floor from 1F to 3F. Furthermore, in the present embodiment, a radio wave repeater 14 is provided for the radio reception repeater 12 in order to prevent loss of signals due to radio wave attenuation from the radio sensor 16 that is far away.

  In such a wireless disaster prevention system of this embodiment, the wireless sensor 16, the wireless reception repeater 12, and the radio wave repeater 14 constitute a wireless network.

  The wireless sensor 16 determines that a fire has occurred when the smoke concentration or temperature due to fire exceeds a predetermined threshold, and wirelessly transmits a fire alarm signal. The wireless reception repeater 12 which is the relay device of the present invention receives the fire alarm signal transmitted from the wireless sensor 16, and causes the alarm current to flow as a contact output to the P-type receiver 10, Send fire alarm signal.

  When the radio repeater 14 receives the fire alert signal transmitted from the wireless sensor 16, the radio repeater 14 relays and transmits the received fire alert signal to the radio reception repeater 12.

  FIG. 2 is a block diagram showing a circuit function of a radio reception repeater to which the present invention is applied with the receiver in the radio disaster prevention system of FIG.

  In FIG. 2, the wireless sensor 16 includes a temperature detector using a smoke detector or a thermistor. For example, when the smoke concentration exceeds a predetermined threshold, it is determined that a fire has occurred, and a fire alarm signal is transmitted to the antenna. 24 is transmitted wirelessly. Note that the wireless communication in the present embodiment performs wireless communication according to the standard of a specific low-power wireless station in the 400 MHz band, for example, in Japan.

  The radio wave repeater 14 relays the fire alarm signal transmitted from the wireless sensor 24 to another wireless repeater or the wireless reception repeater 12.

  The radio reception repeater 12 serving as a relay device of the present invention includes a CPU 28, a radio communication unit 30, an antenna 32, a line input / output unit 34, a power supply circuit unit 36, and a display circuit unit 38. A power supply line 20 and a signal line 22 drawn from the receiver 10 are connected to the line input / output unit 34. The power supply line 20 supplies a predetermined DC power supply voltage from the receiver 10, and a power supply circuit unit 36 generates a power supply voltage for a repeater circuit including the CPU 28.

  The CPU 28 is provided with a relay processing unit 42 and a recovery processing unit 44 as functions realized by executing the program. When the relay processing unit 42 receives the fire alarm signal from the wireless sensor 24 by the radio circuit unit 30, the signal line 22 drawn from the receiver 10 is short-circuited to a low impedance to generate a fire alarm current. The fire alarm signal is transmitted to the receiver 10.

  The line input / output unit 34 is provided with a recovery detection circuit unit 40. When the receiver 10 recovers the wireless reception repeater 12 that is receiving the fire alarm signal, the application of the line voltage to the signal line 22 is stopped by operating the recovery switch. Transmission of the restoration signal from the receiver 10 due to the stop of application of the line voltage is detected by the restoration detection circuit unit 40, and the restoration processing unit 44 of the CPU 28 performs the restoration operation of the repeater circuit.

  Regarding the detection of the recovery signal by the recovery detection circuit unit 40, the use of a photocoupler eliminates the need for a short-circuit connection between the ground terminal GND of the power line 20 and the common terminal C of the signal line 22, and further uses a photocoupler. However, current consumption flowing in the signal line 20 is reduced.

  The receiver 10 is provided with a CPU 46. For the CPU 46, a power supply unit 48, line reception units 50-1 to 50-3, a display unit 52, an acoustic alarm unit 54, an operation unit 56, a transfer unit 58, and the like. A memory 60 is provided. The CPU 46 is provided with a fire monitoring unit 62 as a function realized by executing the program.

  The power supply unit 10 supplies a predetermined DC power supply voltage, for example, DC 30 volts, through the power line 20. For example, DC 24 volts is supplied as a predetermined DC line voltage to the signal line 22 drawn from the line receivers 50-1 to 50-3.

  The transmission of the fire alarm signal from the radio reception repeater 12 is performed by causing the alarm current to flow through the signal line 22. Therefore, the line receiver 50-1 detects the alarm current flowing through the signal line 18 and detects the CPU 46. And fire alarm display and acoustic alarm output by the fire monitoring unit 62 are performed.

  The recovery operation of the wireless reception repeater 12 that has transmitted the fire alarm signal is performed by a recovery signal from the receiver 10. For this reason, when receiving a restoration signal from the CPU 46 based on the operation of the restoration switch provided in the operation unit 56, the line receiving unit 50-1 stops the voltage application to the signal line 22 to 0 volts.

  FIG. 3 is a circuit block diagram showing an embodiment of a recovery detection circuit provided in the radio reception repeater of FIG. In FIG. 3, the signal line 22 drawn from the receiver 10 is connected to the line terminal L and the common terminal C of the radio reception repeater 12, and the oscillation provided in the recovery detection circuit unit 40 to the line terminal L and the common terminal C. A circuit 64 is connected and operated by a line voltage, and a pulse signal is oscillated intermittently at a predetermined cycle.

The output of the oscillation circuit 64 is connected to an LED 68 of a photocoupler 60 as an isolation circuit via a current limiting resistor R1, a phototransistor 70 is provided opposite the LED 68, and the collector of the phototransistor 70 is connected via a resistor R12. Pulled up to power supply voltage V _DD .

  In this way, the input side and the output side of the recovery detection circuit 40 are electrically insulated and separated using the photocoupler 66, so that the power supply connected to the power supply terminal V of the power supply line 20 from the receiver 10 and the ground terminal GND. Even when power is supplied from the circuit unit 36 to the repeater circuit including the CPU 28, the signal line 28 side including the oscillation circuit 64 is electrically isolated by the photocoupler 66. There is no need to short-circuit the terminal C to the ground terminal GND of the power line 20.

  The oscillation circuit 64 connected between the line terminal L and the common terminal C of the signal line 18 oscillates the photocoupler 60 intermittently by oscillating a pulse signal having a pulse width of 100 μs at a period of 10 ms, for example. Compared with the case where the line voltage is directly applied to the photocoupler 66 to always drive, the current consumption flowing in the signal line 22 can be greatly reduced.

  FIG. 4 is a time chart showing signal waveforms of respective parts in the recovery detection circuit unit 40 of FIG. FIG. 4A shows the line voltage of the signal line 22. In normal times, for example, DC 24 volts is applied, and if the restoration signal is transmitted from time t1 to time t3, the line voltage is applied during that time. Stopped to 0 volts.

  FIG. 4B shows a pulse signal output from the oscillation circuit 60, and oscillates a pulse signal having a pulse width T2 in the cycle T1 by the operation of the oscillation circuit 64 when the line voltage is DC 24 volts. Here, for example, the period T1 is 10 ms, and the pulse width T2 is 100 μs.

  The oscillation pulse signal stops oscillating when the application of the line voltage stops at time t1 and drops to 0 volts, and the elapsed time from the rising time t0 of the last pulse signal before the oscillation stops is longer than the period T2 of the pulse signal. At time t2 when time T3 is reached, it is determined that the line voltage application on the signal line 22 has been stopped, that is, the recovery signal has been transmitted, and a recovery determination signal is output to perform a recovery operation by resetting the repeater circuit, etc. .

  FIG. 5 is a flowchart showing recovery processing by the CPU of FIG. 2 using the output of the recovery detection circuit unit of FIG.

  In FIG. 5, it is first determined in step S1 whether or not there is an oscillation pulse. If it is determined that there is an oscillation pulse, the process proceeds to step S2, and the timer set at a predetermined time T3 in FIG.

  Subsequently, it is determined whether or not there is an oscillation pulse in step S3 during the timer operation. If there is no oscillation pulse, it is determined whether or not the elapsed time of the timer has reached the set time T3 in step S4. If it is determined in step S4 that the elapsed time by the timer has reached the set time T3 without determining the oscillation pulse in step S3, the process proceeds to step S5, where the recovery instruction from the receiver 10 is recognized and the recovery operation is performed. .

  If it is determined in step S4 that the oscillation pulse is present before the elapsed time of the timer reaches the set time T3, the process returns to step S2 to reset the timer and repeat the same processing.

  FIG. 6 is a circuit diagram showing another embodiment of the recovery detection circuit 40 provided in the wireless reception repeater of FIG. 2. In this embodiment, the photocoupler 66 of FIG. 3 is changed to an AC coupling amplifier. It is characterized by that.

  In FIG. 6, the line terminal L and the common terminal C of the radio reception repeater 12 to which the signal line 18 drawn from the receiver 10 is connected are connected to the oscillation of the recovery detection circuit unit 40 as in the embodiment of FIG. A circuit 64 is connected and operated by a line voltage, and a pulse signal is oscillated intermittently at a predetermined cycle.

  The output of the oscillation circuit 64 is input to the differential input type amplifier 72 via the DC cut capacitors C1 and C2, and separated into a DC direction to the oscillation circuit 64 side to output an oscillation pulse. The amplifier 72 operates as a buffer amplifier with the amplification factor set to 1 or a comparator with the amplification factor set to infinity. In the figure, the resistance for generating the bias voltage is not clearly shown.

  Even in this embodiment, the amplifier 72 is AC-coupled to the oscillation circuit 64 side via the DC-cut capacitors C1 and C2, so that they are separated in a DC manner, and the common terminal C of the signal line 22 is connected to the power line 20 There is no need to short-circuit to the ground terminal GND.

  The oscillation circuit 64 connected between the line terminal L and the common terminal C of the signal line 22 oscillates a pulse signal having a pulse width T2 of 100 μs at a period T1 of 10 ms, for example, and intermittently drives the amplifier 72. Compared with the case where the line voltage is directly applied to the photocoupler 116 to always drive the photocoupler 116, the current consumption flowing through the signal line 22 can be greatly reduced.

  FIG. 7 is a circuit diagram showing another embodiment of the recovery detection circuit provided in the radio reception repeater of FIG. 2. This embodiment starts oscillation by stopping application of the line voltage, that is, transmission of the recovery signal. It is characterized by doing so.

  In the recovery detection circuit unit 40 of FIG. 7, a capacitor C3 is connected to the line terminal L and the common terminal C, to which the signal line 22 from the receiver 10 is connected, via a backflow prevention diode D1, and the capacitor C3. Is charged to DC 24 volts, which is a line voltage.

  Following the capacitor C3, a voltage detection circuit 74 is provided. The voltage detection circuit 74 operates using the charging voltage of the capacitor C3 as a power supply voltage, inputs a line voltage from the line terminal L side of the diode D1, and the line voltage has a predetermined threshold voltage Vth, for example, the receiver 10 has a line voltage of 24 volts. If the voltage is applied, half of the 12 volts is set as the threshold voltage Vth, and if the line voltage is equal to or higher than the threshold voltage Vth, a voltage detection signal having an H level logic is output. A voltage detection signal having level logic is output.

  Following the voltage detection circuit 74, a switch circuit 76 is provided, and the oscillation circuit 64 is connected via the switch circuit 76 as a load of a power source charged in the capacitor C3. The switch circuit 76 includes a PNP transistor 78 and resistors R3 and R4.

  When the line voltage is equal to or higher than the threshold voltage Vth and the voltage detection circuit 74 outputs an H level signal, the transistor 76 is turned off, power is not supplied from the capacitor C3 to the oscillation circuit 64, and the oscillation circuit 64 outputs a pulse signal. To stop oscillation.

  When the application of the line voltage is stopped as transmission of the recovery signal from the receiver 10, the line voltage falls below the threshold voltage Vth, the output of the voltage detection circuit 74 falls from the H level signal to the L signal, and the transistor 78 is turned on. Then, the charging voltage of the capacitor C3 is supplied as the power supply voltage to the oscillation circuit 64, and the oscillation circuit 64 outputs an oscillation pulse until the discharge of the capacitor C3 is completed.

  Following the oscillation circuit 64, as in the embodiment of FIG. 3, a photocoupler 66 as an isolation circuit is provided to electrically isolate the circuit on the signal line 22 side from the repeater circuit unit including the CPU. .

  FIG. 8 is a time chart showing signal waveforms of respective parts in the recovery detection circuit unit 40 of FIG. FIG. 8A shows the line voltage, which is normally 24 VDC, and when the restoration signal is transmitted from the receiver 10 from time t1 to time t2, the application of the line voltage 24 volt is stopped, 0 volts.

  This drop in the line voltage to 0 volts is detected by the voltage detection circuit 74, a voltage detection signal having an L level logic is output to the switch circuit 76, the transistor 78 is turned on, and the oscillation circuit 64 is charged to the charging voltage of the capacitor C3. Is operated as a power supply voltage, and a pulse signal is oscillated from time T1 to time t2.

  At this time, the line voltage of the signal line 22 is 0 volts, but the voltage charged in the capacitor C3 via the diode D1 is supplied to the voltage detection circuit 74, the switch circuit 76, and the oscillation circuit 64 as a power supply voltage. Even if the application is stopped and becomes 0 volts, the power can be supplied effectively and the operation can be performed.

  FIG. 8C shows a recovery determination signal. When a predetermined number (for example, 3) or more of oscillation pulses are input within a certain time (for example, 100 ms), the recovery determination signal is generated and the relay circuit unit is recovered. The action can be performed.

  FIG. 9 is a flowchart showing the recovery process by the CPU of FIG. 2 using the output of the recovery detection circuit unit of FIG. 7. Compared with the recovery process of FIG. 5, the interrupt operation by the oscillation pulse is not applied during the normal operation. The load on the part can be reduced.

  In FIG. 9, it is first determined whether or not there is an oscillation pulse in step S11. If it is determined that there is an oscillation pulse, the process proceeds to step S12, and a timer is started.

  Subsequently, in step S13 during the timer operation, it is determined whether or not the number of pulses is equal to or greater than a predetermined number, for example, 3 or more. ing. If it is determined in step S13 that the number of pulses has exceeded the predetermined number before the predetermined time elapses, the process proceeds to step S15 to recognize the recovery instruction from the receiver 10 and perform the recovery operation.

  If the elapse of the predetermined time by the timer is determined in step S14 before determining that the number of pulses is equal to or greater than the predetermined number in step S13, the process returns to step S11 and the same processing is repeated.

  Even in the embodiment of FIG. 7, it is necessary to short-circuit the common terminal C of the signal line 22 to the ground terminal GND of the power supply line 20 by electrically separating the oscillation circuit 64 side through the photocoupler 66. There is no.

  Further, when the application of the line voltage of the signal line 22 is stopped, the transmission of the restoration signal is determined by operating the oscillation circuit 64 with the charging voltage of the capacitor C3 and outputting the oscillation pulse. In contrast to the embodiment, the current consumption flowing in the signal line 22 can be greatly reduced.

  FIG. 10 shows another embodiment of the recovery detection circuit provided in the radio reception repeater of FIG. 2 that oscillates a pulse signal when line voltage application is stopped. 10 is the same as the embodiment of FIG. 7 except for the photocoupler 66, and the photocoupler 66 of FIG. 7 is changed to a differential amplifier 72 that is AC-coupled by capacitors C1 and C2.

  In the embodiment of FIG. 10 as well, the amplifier 72 is AC-coupled to the oscillation circuit 64 side via the DC cut capacitors C1 and C2 and separated into DC, so that the common terminal C of the signal line 22 is separated. Need not be short-circuited to the ground terminal GND of the power line 20.

  In addition, since the oscillation circuit 64 is operated by the charging voltage of the capacitor C3 when the voltage application of the signal line 22 is stopped and the oscillation pulse is output to determine the transmission of the restoration signal, the embodiment of FIGS. In contrast, the current consumption flowing in the signal line 22 can be greatly reduced.

The present invention includes modifications as appropriate without impairing the object and advantages thereof, and is not limited by the numerical values shown in the above-described embodiments.

Explanatory drawing which showed embodiment of the wireless disaster prevention system to which this invention was applied The block diagram which showed the circuit function of the repeater for radio | wireless reception to which this invention was applied about the radio | wireless disaster prevention system of FIG. 1 with the receiver 2 is a circuit diagram showing an embodiment of a recovery detection circuit provided in the radio reception repeater of FIG. 2 that stops oscillation when line voltage application is stopped. Time chart showing signal waveforms of each part in the recovery detection circuit part of FIG. 2 is a flowchart showing recovery processing by the CPU of FIG. 2 using the output of the recovery detection circuit unit of FIG. FIG. 3 is a circuit diagram showing another embodiment of the recovery detection circuit provided in the wireless reception repeater of FIG. 2 in which the photocoupler of FIG. 2 is a circuit diagram showing another embodiment of a recovery detection circuit provided in the radio reception repeater of FIG. 2 that starts oscillation when line voltage application is stopped. FIG. 7 is a time chart showing signal waveforms of respective parts in the recovery detection circuit part of FIG. The flowchart which showed the recovery process by CPU of FIG. 2 using the output of the recovery detection circuit part of FIG. FIG. 7 is a circuit diagram showing another embodiment of the recovery detection circuit provided in the wireless reception repeater of FIG. 2 in which the photocoupler of FIG. Circuit diagram showing a conventional recovery detection circuit Circuit diagram showing a conventional recovery detection circuit using a photocoupler

Explanation of symbols

10: P-type receiver 12: Radio reception repeater 14: Radio wave repeaters 16, 16-1 to 16-3: Wireless sensor 18: Transmission line 20: Power supply line 22: Signal lines 24, 26, 32: Antennas 28 and 46: CPU
30: Wireless communication unit 34: Line input / output unit 36: Power supply circuit unit 38: Display circuit unit 40: Recovery detection circuit unit 42: Relay processing unit 44: Recovery processing unit 48: Power supply units 50-1 to 50-3: Line receiver 52: Display unit 54: Sound alarm unit 56: Operation unit 58: Transfer unit 62: Memory 64: Oscillator circuit 66: Photocoupler 68: LED
70: Phototransistor 72: Amplifier 74: Voltage detection circuit 76: Switch circuit 78: Transistor

Claims (5)

In a relay device connected to each of a pair of power lines drawn from a receiver and applied with a predetermined DC power supply voltage and a pair of signal lines applied with a predetermined DC power line voltage,
The pulse connected between the pair of signal lines, intermittently oscillating a pulse signal in response to the application of the DC line voltage, and temporarily stopping the voltage application of the pair of signal lines. An oscillation circuit for stopping signal oscillation;
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
A repeater circuit that operates by supplying power from the pair of power lines, determines a transmission of a recovery signal from the receiver by stopping a pulse signal from the isolation circuit, and performs a recovery operation;
A relay apparatus comprising:
In a relay device connected to each of a pair of power lines drawn from a receiver and applied with a predetermined DC power supply voltage and a pair of signal lines applied with a predetermined DC power line voltage,
A capacitor connected through a diode or resistor that prevents reverse flow between the pair of signal lines, and charged to the DC line voltage;
An oscillation circuit that intermittently oscillates a pulse signal;
A switch circuit for supplying a charging voltage of the capacitor as a power supply voltage to the oscillation circuit;
Operates by receiving power supply from the capacitor, and when it is detected that the applied voltage of the pair of signal lines is equal to or higher than a predetermined voltage, the switch circuit is turned off to stop the oscillation circuit, and from the receiver Voltage detection circuit that turns on the switch circuit and intermittently oscillates a pulse signal by the operation of the oscillation circuit when detecting a voltage drop due to a temporary suspension of voltage application of the pair of signal lines at the time of restoration signal transmission When,
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
A repeater circuit that operates by supplying power from the pair of power lines, performs a recovery operation by determining transmission of a recovery signal from the receiver by inputting a pulse signal from the isolation circuit, and
A relay apparatus comprising:
3. The relay device according to claim 1, wherein the isolation circuit includes a light emitting element that is driven to emit light by a pulse signal from the oscillation circuit, and a phototransistor that is turned on by light from the light emitting element. A relay device characterized by being a coupler.
3. The relay apparatus according to claim 1, wherein the isolation circuit is an amplifier in which an output of the oscillation circuit is input-connected through a DC cut capacitor.
  3. The relay device according to claim 1, wherein the repeater circuit detects a fire and transmits a notification wireless signal between the pair of signal lines when a notification wireless signal is transmitted from a wireless sensor. A relay device characterized by sending a signal current to the receiver and transmitting an alarm signal to the receiver.

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