JP2824002B2 - Emergency broadcast equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency broadcast device used in the event of a fire or the like, and more particularly to an emergency broadcast device provided with a function for monitoring the disconnection of a protective fuse provided in the emergency broadcast device.

[0002]

2. Description of the Related Art Conventionally, an emergency broadcasting device is installed in a specific legally stipulated building, and in the event of an emergency such as a fire, is notified by an alarm sound such as a siren and evacuation guidance by voice. Broadcast. FIG. 3 shows a conventional emergency broadcast device. The emergency broadcast device 1 installed in a monitoring center or the like has an alarm switch and a voice message signal for evacuation guidance by a magnetic tape or a voice synthesizer. An audio processing circuit 2 which is generated at the time is provided, and the audio signal is amplified by the power amplifier 3 and then supplied to the coupling transformer 4 and further sent to the speaker 6 installed in the notification area by the lines L1 and L2 via the protective fuse 5. ing. A message spoken when the microphone start switch is operated is also input to the voice processing circuit 2 and broadcast from a speaker in the same manner.

Here, the wiring from the emergency broadcasting device 1 to the speaker 6 is long, and the output voltage of the amplifier 3 is as high as 100 V at Vpp, for example, in order to output a sufficient volume from the speaker 6. Therefore, a protection fuse 5 is provided to prevent the power amplifier 3 from being destroyed due to a short circuit on the load side. The speaker 6 has a built-in coupling transformer 7 for driving the voice coil speaker 8 after reducing the high voltage from the power amplifier 3.

[0004]

However, in such a conventional emergency broadcast apparatus, a protection fuse for dealing with a short circuit on the load side is provided at the output of the power amplifier. The presence or absence is not particularly monitored, and if the protection fuse is blown by any chance, there is a problem that an emergency broadcast cannot be performed in the event of an emergency such as a fire.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has as its object to provide an emergency broadcast apparatus capable of always monitoring an open state of a protective fuse and maintaining an emergency broadcast state. Aim.

[0006]

In order to achieve this object, the present invention is configured as follows. The reference numerals in the drawings of the embodiments are also shown. First, according to the present invention, when an emergency such as a fire occurs, the audio signal from the audio processing circuit 2 is amplified by the amplifier 3 and then the coupling transformer 4 and the protection fuse 5 are amplified.
And an emergency broadcast device that sends the signal to a signal line via a speaker 6 and broadcasts the signal to a speaker 6 installed in a notification area.

The present invention relates to such an emergency broadcast device,
A start switch 10 for starting an emergency broadcast, and a protection fuse 5 is disconnected from a line between the coupling transformer 4 and the line based on a switching signal of an off position of the start switch 10 and connected between a DC power supply and a monitoring current is supplied. A circuit and a disconnection detecting circuit for notifying the disconnection of the protection fuse 5 when the monitoring current flowing through the protection fuse 5 is no longer detected by the monitoring circuit are provided.

The present invention also provides a start switch 10 for starting an emergency broadcast, a timer circuit 18 for outputting an inspection signal at regular intervals while a switching signal for turning off the start switch 10 is obtained, and a timer circuit 18. Each time an inspection signal is obtained from the control circuit, the protection fuse 5 is disconnected from the line between the coupling transformer 4 and the line, and is connected between the DC power supply and a monitoring circuit for flowing a monitoring current.
And a disconnection detection circuit for notifying the disconnection of the protection fuse 5 when the monitoring current flowing through the protection fuse 5 is no longer detected.

Further, in addition to the monitoring control by the timer circuit 18, the audio processing circuit 2 outputs a silent signal in a silent state during an emergency broadcast by turning on the start switch 10, so that the monitoring circuit is activated by the silent signal. A monitoring current may be supplied to the protection fuse 5 to monitor the disconnection during broadcasting.

[0010]

According to the emergency broadcast apparatus of the present invention having such a configuration, the output of the amplifier is normally AC-coupled to the line side by the coupling transformer during normal emergency broadcast, and the amplifier is connected to the protective fuse. Since no voltage is applied to the protection fuse from the line, the protection fuse is disconnected from the line and separately connected to a DC power supply to supply a monitoring current, and a disconnection alarm is issued when the monitoring current is cut off.

The monitoring of the disconnection is continuously performed at times other than the broadcasting when the start switch is turned off, or is periodically performed at regular intervals by a timer. Further, by using the silent signal sent from the audio processing circuit, the state of the protection fuse can be monitored even during broadcasting.

[0012]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention. In FIG. 1, an emergency broadcast device 1 is provided with an audio processing circuit 2, an amplifier 3 for power amplifying an audio signal, a coupling transformer 4 for AC coupling an audio signal, and a protection fuse 5, and is installed in a notification area by lines L1 and L2. Are connected in parallel as a load. The sound processing circuit 2 stores in advance the alarm sound to be broadcast in an emergency such as a fire and the sound information of the evacuation guidance message. When the activation switch 10 is turned on and the activation signal E1 is received, each of the alarm sound and the evacuation guidance message is transmitted. The audio signal is reproduced and the amplifier 3
Output to

As a specific example of the audio processing circuit 2, a magnetic tape reproducing device or an audio synthesizing circuit can be used. The start switch 10 is normally switched to the off position as shown in FIG. On the output side of the start switch 10, a monitoring circuit for the protection fuse 5 including the transistor 11, the relay 12, the switching relay contacts 13 and 14, the resistor R1, and the diode DA is provided.

The monitoring circuit of the protection fuse 5 has a relay 12 as a collector load of the transistor 11, and switching relay contacts 13 and 14 are inserted before and after the protection fuse 5. When the start switch 10 is in the OFF position, the transistor 11 is turned off, so that the relay 12 is not operated, the switching relay contacts 13 and 14 are switched to the illustrated side a, and the protection fuse 5 is disconnected from the coupling transformer 4 and the line L1.

At the same time, the switching relay contacts 13 and 14 disconnect the protection fuse 5 from between the coupling transformer 4 and the line L1. Relay contact 1
Numeral 4 connects the other side of the fuse 5 to ground. Therefore, the DC power supply voltage is applied to the protection fuse 5 by the resistor R1 in the switching state of the illustrated switching relay contacts 13 and 14, and a weak monitoring current determined by the resistor R1 flows through the protection fuse 5.

A disconnection detecting circuit for detecting a disconnection of the protection fuse 5 based on a monitoring current flowing through the protection fuse 5 includes a transistor 15, a resistor R2, and a disconnection indicating lamp 16. Transistor 15 has resistor R1 and switching relay contact 1
3 is connected to the base, the disconnection indicator lamp 16 is connected to the collector via the resistor R2, and the emitter is grounded. If the protection fuse 5 is normal, a weak monitoring current flows through the protection fuse 5 by the resistor R1, the base voltage of the transistor 15 is almost 0 V, the transistor 15 is turned off, and the disconnection indicator light 16 is turned off. When the protective fuse 5 is disconnected, the power supply voltage is applied to the base of the transistor 15 to turn on the transistor 15 and the disconnection indicator lights.

Next, the operation of the embodiment of FIG. 1 will be described. In the steady monitoring state, the start switch 10 is in the off position shown in the figure, the transistor 11 is also turned off, and the relay 12 is not operated. When the relay 12 is not operated, the switching relay contacts 13 and 14 are switched to the a side as shown in FIG.
A direct current voltage is applied to the protection fuse 5, and a weak monitoring current determined by the resistor R1 is constantly flowing.

In the monitoring state of the protection fuse 5 in such a steady monitoring state, if the fuse 5 is blown, the power supply voltage is substantially applied to the base of the transistor 15 through the resistor R1 to turn on, and the disconnection indicator lamp 16 lights up to notify the disconnection of the protection fuse 5. On the other hand, when an emergency such as a fire occurs, the start switch 10 is switched to the ON position on the b side.

When the start switch 10 is switched to the ON position for performing an emergency broadcast, the start signal E1 is applied to the sound processing circuit 22, and the sound signals of the alarm sound of the siren and the evacuation guidance sound message are reproduced. , And supplied to the coupling transformer 4. The switching of the start switch 10 may be performed manually or may be performed by a relay drive based on a notification signal from a fire receiving panel.

At the same time when the start switch 10 is turned on, the switching signal E2 is output, the transistor 11 is turned on, and the relay 12 is operated, so that the switching relay contacts 13 and 14 are switched to the b side, and the protection fuse 5 is connected to the coupling transformer 4 And the line L1. For this reason, the audio signal is sent to the lines L1 and L2 via the protective fuse 5 by the AC coupling by the coupling transformer 4, and the signal voltage is attenuated by the coupling transformer 7 of the speaker 6, and then the voice coil speaker 8 is driven to generate an alarm. Sound and voice guidance for evacuation guidance are output.

FIG. 2 is a circuit block diagram showing another embodiment of the present invention. In this embodiment, the disconnection of the protection fuse is periodically monitored in a normal state where no emergency broadcast is performed. It is characterized by the following. In FIG. 2, an activation switch 10 is an on / off type switch, and the emergency operation of the activation switch 10 activates the audio processing circuit 2 to perform an emergency broadcast.

The monitoring circuit, which separates the protection fuse 5 from the coupling transformer 4 and the line L1 and allows a monitoring current to flow by applying a DC voltage, is periodically driven by a timer circuit 18 at regular intervals. The timer circuit 18 outputs a check signal to the transistor 11 via the diode D1 and the resistor R1 each time a preset fixed time is reached. Here, the timer circuit 18 outputs an inspection signal and is internally reset at the same time, and starts counting the set time again.

The collector of the transistor 11 has a relay 1
1, the relay 12 has switching relay contacts 13 and 14 as in the embodiment of FIG. 1, and disconnects the protective fuse 5 from the audio line and applies a DC voltage. The switching relay contacts 13 and 14 are shown in a state where the relay 12 is turned off and the protection fuse 5 is connected to the audio line.

The disconnection detecting circuit is composed of a transistor 15, a resistor R2 and a disconnection indicating lamp 16 as in the embodiment of FIG. 1. The disconnection detecting circuit can maintain the disconnection detecting state even when the timer output of the timer circuit 18 is disconnected. Transistor 1
7, a self-holding circuit is provided by the resistors R3, R4, R5, the capacitor C1, the diode D4 and the transistor 11. This self-holding circuit turns on the transistor 11 and drives the relay 12 in response to the inspection signal from the timer circuit 18 with the protection fuse 5 blown. At the same time, the transistor 17 is turned on by turning on the transistor 11.

By the operation of the relay 12, the switching relay contact 13,
14 switches to the a side and receives supply of DC power,
Since the protection fuse 5 is blown, the transistor 15
Turns on, and the disconnection indicator lamp 16 is turned on. Transistor 1
When 7 turns on, the capacitor C1 connected in parallel with the resistor R5 via the resistor R4 is inductively conducted. Thereafter, even if the inspection signal from the timer circuit 18 is cut off, the transistor 15 is kept on by the self-holding circuit of the transistor 11, and the disconnection indicator lamp 16 is kept on.

Further, the embodiment of FIG. 2 has a function of outputting a silence signal E3 to the outside in a state of a silence signal between audio signals during an emergency broadcast with the start switch 10 turned on. For example, when the audio processing circuit 2 repeats the audio output of "Woo, Woo", "Fire", and "Woo, Woo", a silence signal E3 is output between "Woo, Woo" and "Fire".

The silence signal from the audio processing circuit 2 is supplied to the base of the transistor 11 via the diode D2 and the resistor R1, and while the silence signal E3 is being obtained, the transistor 11 is turned on. When the switching relay contacts 13 and 14 are switched to the a side by operation, a monitoring current caused by the application of a DC voltage flows to monitor the disconnection of the protection fuse 5.

Therefore, during the broadcast, the protection fuse 5
Even if the protection fuse 5 is disconnected, the disconnection of the protection fuse 5 is detected at the time of the silence signal E3, the disconnection indicator lamp 16 is turned on, and it can be notified that the broadcast has been stopped due to the disconnection of the protection fuse 5. In the embodiment of FIG. 2, the timer circuit 1
8, the disconnection of the protection fuse 5 is also detected by the silence signal E3 from the audio processing circuit 2; however, it is also possible to perform the regular disconnection monitoring by the timer circuit 18 alone without using the silence signal E3. Of course.

In the above embodiment, an emergency broadcast device is taken as an example. However, other broadcast devices may be used once a week, once a month, etc. without being used on a daily basis. The present invention can be applied to broadcasting devices that are used at intervals and provided with a protective fuse on the output side. Further, in the above embodiment, the broadcast message signal is transmitted from the voice processing circuit 2 when the start switch 10 is turned on in conjunction with the fire reception. However, the start switch 10 is a microphone switch, and the voice of the person in charge is turned on by the microphone switch. The signal may be output from the audio processing circuit 2 and broadcast.

[0030]

As described above, according to the present invention, the state of a protection fuse provided in an emergency broadcast device which is not used on a daily basis is monitored, and if a disconnection occurs, the protection fuse is protected. Can be notified, and a situation in which an emergency broadcast cannot be performed due to the disconnection of the protection fuse can be avoided beforehand, and the reliability of the emergency broadcast device can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

FIG. 2 is a circuit block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram of a conventional device.

[Explanation of symbols]

 1: Emergency broadcast device 2: Audio processing circuit 3: Amplifier 4: Coupling transformer 5: Protection fuse 6: Speaker 7: Coupling transformer 8: Voice coil speaker 10: Start-up switch 11, 15, 17: Transistor 12: Relay 13, 14 ： Switching relay contact 16 ： Disconnection indicator 18 ： Timer circuit

Claims (3)

(57) [Claims] When an emergency such as a fire occurs, an audio signal from an audio processing circuit is amplified by an amplifier and then sent to a signal line via a coupling transformer and a protection fuse.
In an emergency broadcast device for broadcasting by sending to a speaker installed in a notification area, a start switch for starting an emergency broadcast, and the protection fuse is connected between the coupling transformer and a line based on a switching signal of an OFF position of the start switch. A monitoring circuit that is disconnected from the line and flows between the DC power supplies to supply a monitoring current, and a disconnection detection circuit that notifies the disconnection of the protection fuse when the monitoring current flowing through the protection fuse is no longer detected by the monitoring circuit. An emergency broadcast device comprising: 2. When an emergency such as a fire occurs, an audio signal from an audio processing circuit is amplified by an amplifier and then transmitted to a signal line via a coupling transformer and a protection fuse.
In an emergency broadcast device for broadcasting by transmitting to a speaker installed in a notification area, a start switch for starting an emergency broadcast and an inspection signal are transmitted at regular intervals while a switching signal for turning off the start switch is obtained. A timer circuit for outputting, a monitoring circuit for disconnecting the protection fuse from the line between the coupling transformer and the line and connecting the protection fuse to a DC power supply to supply a monitoring current each time an inspection signal is obtained from the timer circuit; An emergency broadcast device, comprising: a disconnection detection circuit for notifying the disconnection of the protection fuse when the monitoring circuit stops detecting a monitoring current flowing through the protection fuse. 3. The emergency broadcast apparatus according to claim 2, wherein said audio processing circuit operates and protects said monitoring circuit by a silent signal output in a silent state during emergency broadcast by turning on said start switch. An emergency broadcast device characterized by sending a monitoring current to a fuse.