JP5237024B2 - Relay device - Google Patents

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 the wireless disaster prevention system for monitoring fire, when installing a plurality of wireless sensors in security area, such as each floor of the building, were detected fire wirelessly sense knowledge unit, floor fire alert signal to the radio reception repeater installed in the unit. Radio reception repeater is connected to the sensor lines from the fire receiver receives the fire alert signal, the fire alarm by passing the alarm current between the sensing line by turning on the relay contacts and the switching element The signal is transmitted to the receiver to give a fire alarm.

Also when the distance from the wireless sensor to the wireless reception relay is long, a radio repeater installed in the middle, and relays the fire radio signals from wireless sensors, fire radio signal by the attenuation of radio waves Is not lost.

According to such a wireless disaster prevention system, it is possible to eliminate the need for a sensor line connecting the wireless reception repeater installed on the floor of the building and the wireless sensor, simplifying the wiring work, and wireless detection. The installation location of the vessel can also be determined as necessary.

However, such a In the radio reception repeater wireless disaster prevention system, as shown in FIG. 11, the power supply line 104 drawn out from the receiver 100 of the radio reception relay 102 the power supply terminal V and the ground terminal connect to GND, and also connects the signal line 106 to the line terminal L and the common terminal C of the radio reception repeater 102. Note that the radio reception repeater stands by in a state where radio signals can be received at all times, and therefore consumes a large amount of current and cannot take power from the signal line.

Repeater circuit (not shown) provided in the radio reception relay 102 operates by receiving supply of predetermined DC power source voltage by the power supply line 104. For example, DC 24 volts is applied as a predetermined line voltage from the receiver 100 between both signal lines 106. When a fire signal is received from the wireless sensor, a switching circuit (not shown) is turned on, and a signal line 106 is activated. A fire alarm signal is transmitted to the receiver 100 by passing an electric current.

The recovery signal to the wireless reception relay 102 due to such recovery operation from the receiver 100 is transmitted. 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 applied between both lines of 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 with the recovery of the receiver 100 is temporarily stopped, the transistor Q1 is turned off to perform the recovery operation of the output signal to the repeater circuit as a logic H level.

However, in the restoration signal detection circuit 108 provided in such a conventional radio reception repeater , 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 apparatus to connect the ground. 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 for assembly and installation. 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 both lines of the signal line 106 are connected. By applying DC 24 volts between them, a current is passed through the light emitting element LED to drive light emission, the phototransistor PT is turned on by the light from the light emitting element LED, and an L level signal is output.

When the voltage applied to the signal line 106 with the recovery of the receiver 100 is temporarily stopped, by light emission of the light emitting device LED phototransistor PT turns off stops, the capacitor C1 is charged via the resistor R15, H 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. If a large current flows in this manner to the signal line 106 to drive the photocoupler 112, the potential fire alert signal from the radio reception repeater 102 in the receiver 100 side you misjudge to have been transmitted For this reason, it is difficult to take an electrical separation method using 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, receives a DC line voltage , oscillates a pulse signal at a predetermined period, and oscillates a pulse signal when transmitting a recovery signal for a receiver that temporarily stops voltage application on a pair of signal lines An oscillation circuit to stop,
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
Relay that operates by supplying power from a pair of power lines and performs recovery operation by determining the transmission of the recovery signal from the receiver when no pulse signal is input from the isolation circuit for a longer time than the specified period Instrument circuit,
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
Oscillation that intermittently oscillates the pulse signal when transmitting the recovery signal of the receiver that temporarily stops the applied voltage between the pair of signal lines, and stops oscillating the pulse signal when the applied voltage of the pair of signal lines is equal to or higher than the specified voltage Circuit ,
And the isolation circuit configured to electrically isolate the pulse signals from the oscillation circuit,
A repeater circuit that operates by supplying power from a pair of power lines, and that performs recovery operation by determining transmission of a recovery signal from a receiver when a predetermined number or more of pulse signals are input from an isolation circuit;
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 comprising the.

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.

When a repeater circuit receives a fire alarm signal from a wireless sensor that detects a fire and transmits a fire alarm signal, it sends a signal current between a pair of signal lines to send the alarm signal to the receiver. To transmit .

  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, Transmit 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 16 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 circuit 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 signal line 22 supplies a predetermined line voltage from the receiver 10.

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 48 supplies a predetermined DC power supply voltage, for example, DC 30 volts, through the power line 20. Further, as the example DC24 volts predetermined times line voltage is supplied to the signal line 22 drawn from the line receiver 50-1～50-3.

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. output to, fire alarm display and acoustic alarm output Ri by the fire monitoring unit 62 is 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 12 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.

Output of the oscillation circuit 64 is connected via the LED 68 to the current limiting resistor R1 photocoupler 66 of an isolation circuit, phototransistor 70 is provided to face the LED 68, the collector of the phototransistor 70 via the resistor R 2 _Is pulled up to the 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 if power is supplied from the circuit unit 36 to the repeater circuit including the CPU 28, the signal line 22 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 66 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. 4 (B) is a pulse signal outputted from the oscillation circuit 64 (oscillation pulse signal), the operation of the oscillation circuit 64 when the line voltage is DC24 volts, a pulse signal comprising a pulse width T2 at periods T1 It is oscillating. 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 volt, and the recovery detection circuit unit 40 determines the elapsed time from the rising time t0 of the last pulse signal before the oscillation is stopped. At time t2 when time T3 that is longer than the period T2 of the pulse signal is reached, it is determined that the application of the line voltage on the signal line 22 is stopped, that is, the recovery signal is transmitted, and the recovery determination signal shown in FIG. Then, the recovery operation is performed by resetting the repeater circuit.

  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 . When reaching the set time T3 of the elapsed time by the timer is determined in step S4, it performs the recovery operation by recognizing the recovery instruction from the receiver 10 proceeds to step S5.

  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 12 of FIG. 2, and this embodiment starts oscillation by stopping the application of the line voltage, that is, transmitting the recovery signal. It was made to do.

  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, and inputs the line voltage from the line terminal L side of the diode D1 . As the threshold voltage Vth, for example, set the 12 volt half if the receiver 10 is applied to the line voltage 24 volts, the voltage detecting circuit 74 is at H level as long as the line voltage is the threshold voltage Vth or more logical A voltage detection signal having a logic of L level is output if the voltage detection signal is lower than the threshold voltage Vth.

  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 photocoupler 66 is provided embodiment similarly to as isolation circuit of FIG. 3, are electrically isolated against the circuit of the signal line 22 side to the repeater circuits including a CPU28 .

  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.

Drop to zero volts of the line voltage is detected by the voltage detection circuit 74, and outputs a voltage detection signal having a logic L level to turn on the transistor 78 to the switch circuit 76, the power supply voltage the charging voltage of the capacitor C3 As a result, the oscillation circuit 64 is operated to oscillate the pulse signal from time t1 to time t2 .

At this time, the line voltage of the signal line 22 is 0 volts, but the charging voltage of the capacitor C3 is supplied to the voltage detection circuit 74, the switch circuit 76, and the oscillation circuit 64 as a power supply voltage via the diode D1, and the line voltage is applied. Even if it stops and becomes 0 volts, it can be operated by supplying power effectively.

FIG. 8C shows a recovery determination signal output from the recovery detection circuit unit 40. A recovery determination signal is generated when a predetermined number (for example, 3) or more of oscillation pulses are input within a certain time (for example, 100 ms). is, it is possible to perform the recovery operation of the repeater circuits.

  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 a predetermined number or more, for example, 3 or more. If it is less than the predetermined number, it is determined in step S14 whether or not the timer has elapsed for a predetermined time, for example, 100 ms. ing. When the number of pulses is determined that reaches or exceeds the predetermined number in step S13 before a predetermined time elapses, performs the recovery operation by recognizing and recovery instruction from the receiver 10 proceeds to step S15.

  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 12 of FIG. 2 that oscillates a pulse signal when the application of the line voltage 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 arbitrary modifications that do not impair the object and advantages thereof and is not limited by the numerical values shown in the above 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: Radio circuit 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 (6)

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,
Is connected between the pair of signal lines, the oscillating a pulse signal receiving application of the DC line voltage in a predetermined cycle, when the recovery signal transmission of the receiver to pause voltage application of said pair of signal lines An oscillation circuit for stopping oscillation of the pulse signal;
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
It operates by supplying power from the pair of power supply lines, and when the pulse signal is not input from the isolation circuit for a time longer than the predetermined period , transmission of a restoration signal from the receiver is determined. A repeater circuit that performs recovery operations;
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,
The pulse signal is intermittently oscillated during transmission of the recovery signal of the receiver that temporarily stops the applied voltage of the pair of signal lines, and the pulse signal is oscillated when the applied voltage of the pair of signal lines is equal to or higher than a predetermined voltage. An oscillation circuit to stop,
An isolation circuit that electrically separates and outputs a pulse signal from the oscillation circuit;
A repeater that operates by supplying power from the pair of power supply lines and performs recovery operation by discriminating transmission of a recovery signal from the receiver when a predetermined number of pulse signals are input from the isolation circuit Circuit,
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:
In the relay apparatus according to any one of claims 1 to 3, wherein the isolation circuit includes a light emitting element driven to emit light by a pulse signal from the oscillation circuit, phototransistor is turned on by the light from the light emitting element It is a photocoupler provided with the relay apparatus characterized by the above-mentioned.
In the relay apparatus according to any one of claims 1 to 3, wherein the isolation circuit includes a relay device, characterized in that said a amplifier with input connection via a capacitor for DC blocking output of the oscillation circuit .
The relay device according to any one of claims 1 to 3 , wherein the relay circuit receives the fire alarm signal from a wireless sensor that detects a fire and transmits a fire alarm signal. The relay apparatus transmits a notification signal to the receiver by causing a signal current to flow between the pair of signal lines.

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