JPH0543585Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is an announcement broadcasting device for a CATV system that receives and reproduces general broadcasts and emergency broadcasts from a center at a terminal using the transmission path of the CATV system. Regarding.

(Prior art) Conventionally, in apartment complexes and multi-tenant buildings, general television broadcasts and independent broadcasts are transmitted to subscriber terminals.
Since a CATV system is installed, this
Announcement broadcasting devices have been proposed that utilize the transmission path of the CATV system to perform general announcement broadcasts and emergency announcement broadcasts in times of disaster, etc. from a center to terminals.

In the case of announcement broadcast equipment that uses the transmission path of such a CATV system, general broadcast equipment and emergency broadcast equipment are installed at the center, and general announcement broadcasts are made during normal times, but in the event of a disaster, broadcasts that are different from general announcement broadcasts are made. Emergency announcements are broadcast using carrier signals. For this reason, subscriber terminals are equipped with a broadcast receiving circuit that switches and receives general broadcasts and emergency broadcasts with different carriers according to each broadcast mode, and in the reception mode of general announcement broadcasts, the volume can be adjusted using the volume control. Although,
In the emergency broadcast reception mode, the emergency broadcast is performed at maximum volume regardless of the volume position to ensure that information necessary for a disaster is conveyed. Furthermore, in order to prevent broadcast reception from becoming impossible in the event of a power outage, the terminal is equipped with a battery for power backup, and upon detection of a power outage, it switches from AC power to battery power, ensuring that emergency announcement broadcasts can be received and played back even in the event of a power outage. That's what I do.

(Problem that the invention attempts to solve) However, in the case of announcement broadcasting equipment that uses the transmission line of the conventional CATV system, if a power outage occurs while performing general announcement broadcasting, the power supply will switch to the battery power supply. As a result, power is shared with the broadcast receiving circuit, and this broadcast reception consumes battery power.If an emergency such as a fire occurs during a prolonged power outage, battery power will be consumed during reception and playback of general broadcasts. The power supply is used up, and there is insufficient power capacity when receiving emergency announcement broadcasts.
There was a risk that emergency broadcasts could not be received and played back.

(Means for Solving the Problems) The present invention has been developed in view of the above-mentioned conventional problems, and it is possible to reduce the consumption of battery power during power outages and to ensure the reception and reproduction of emergency announcement broadcasts. The purpose is to provide an announcement broadcasting device for a CATV system in which each terminal is equipped with a power outage detection circuit that detects a power outage, a power outage detection circuit that switches the broadcast receiving circuit to an emergency announcement broadcast reception mode upon detection of a power outage, and a battery power supply. is supplied to the broadcast receiving circuit, and further provided with a means for supplying the broadcast signal from the speaker to the control so as to reproduce it louder than the general announcement broadcast signal, so that in the event of a power outage, the emergency broadcast is always received, and the general announcement broadcast is By not performing reception playback even if it is being performed, battery power consumption is suppressed and preparation is made for the reception of emergency announcement broadcasts.

(Embodiment) The figure is a block diagram showing a device installed in a terminal as an embodiment of the present invention.

First, to explain the configuration, 1 is a broadcast receiving circuit that selectively receives and reproduces general notification broadcast signals and emergency notification broadcast signals that have different carrier frequencies, and 2 is a broadcast receiving circuit that receives and reproduces general notification broadcast signals and emergency notification broadcast signals that have different carrier frequencies. This is a control circuit that detects a broadcast mode and switches the reception mode in the broadcast reception circuit 1 according to the detected broadcast mode. The transmission line (coaxial cable line) of the CATV system is connected to the broadcast receiving circuit 1 and the control circuit 2 via a distributor 3, and the broadcast signal from the center is input by dividing into two parts by the distributor 3. has been done.

Next, the details of the broadcast receiving circuit 1 will be explained.
is a front end, which is switched to the reception mode of general announcement broadcast and emergency announcement broadcast by a control signal based on the broadcast mode detected by the control circuit 2. Specifically, the local oscillation frequency is switched according to the carrier frequency of the general announcement broadcast and the emergency announcement broadcast.
5 is an IF circuit that performs intermediate frequency amplification of the broadcast signal that is selected for reception by the front end 4 and converted into an intermediate frequency signal; 6 is a detection circuit that detects the broadcast audio signal from the output signal of the IF circuit 5; 7 is a detection circuit; circuit 6
This is an audio amplifier that amplifies the broadcast audio signal output from the speaker 8 and outputs it to the speaker 8. A volume 9 for volume adjustment is provided between the detection circuit 6 and the audio amplifier 7, and a gate circuit 10 using an analog switch or the like is connected in parallel with the volume 9, which will be explained later. Control circuit 2
The gate 10 is closed by the control output (power supply) when receiving general broadcasts from the control circuit 2 to enable volume adjustment by the volume 9, while the control output (power supply) from the control circuit 2 when receiving emergency announcement broadcasts. When the signal is cut off, the gate 10 opens and the volume 9 is bypassed, and when an emergency broadcast is received, reception and reproduction are performed at the maximum volume.

Next, the details of the control circuit 2 will be described. Reference numeral 11 denotes a front end, which tunes only the carrier frequency of, for example, an emergency announcement broadcast and converts it into an intermediate frequency signal by setting a local oscillation frequency. 12 is an IF circuit that amplifies the intermediate frequency signal of the emergency announcement broadcast obtained by the front end 11; 13 is a detection circuit that detects the intermediate frequency signal of the emergency announcement broadcast and obtains a DC output;
14 is when the detection output of the detection circuit 13 is obtained,
That is, when the broadcast mode of the emergency broadcast is detected, power is supplied to the emergency broadcast power supply line 15 from the power supply unit which will be explained later, and when the detection output of the detection circuit 13 is not obtained, that is, the general announcement is made. When the broadcast mode of broadcasting is detected, the logic circuit supplies power to the general broadcast power line 16 from the power supply section.

The emergency broadcasting power line 15 and the general broadcasting power line 16 drawn out from this logic circuit 14 are connected to the broadcasting receiving circuit 1, and the front end 4 is provided with a switch for switching the receiving mode between the general announcement broadcast and the emergency announcement broadcast. A general broadcasting power supply line 16 is connected to the gate circuit 10, and when power is supplied from the general broadcasting power supply line 16, the gate 10 is closed to control the volume 9.
The IF circuit 5, the detection circuit 6, and the audio amplifier 7 each have a diode connection from the emergency broadcasting power supply line 15 and the general broadcasting power supply line 16, respectively. Parallel power supply is provided via the

Next, to explain the configuration of the power supply section, the power supply circuit 17 generates circuit power by rectifying and smoothing AC100V.
A battery 18 is provided for backing up the power in the event of a power outage, and the output of the power supply circuit 17 is provided to each circuit section of the control circuit 2 and is also connected to the general broadcasting power supply line 16 via the logic circuit 14 of the control circuit 2. Alternatively, it is output to either the emergency broadcast power line 15 and supplies power to the broadcast receiving circuit 1. The battery 18 is connected to the output of the power supply circuit 17 via a charging resistor R1 and a reverse current blocking diode D1, and the power output of the battery 18 is connected to the drive circuit 19 via a diode D2.
is given to. In addition, the power supply section includes a power supply circuit 1.
A power failure detection circuit 20 is provided to monitor the power output of the power supply circuit 17, and the output voltage of the power supply circuit 17 becomes OV due to a power failure.
When this happens, the power failure detection circuit 20 provides a power failure detection output to the drive circuit 19, closes the internal contacts of the drive circuit 19, and provides the power output of the battery 18 to the power supply line 21. This drive circuit 1
The power supply line 21 from 9 is connected to the emergency broadcasting power line 15 from the control circuit 2. Therefore, in the event of a power outage, battery power is not supplied to the broadcast receiving circuit 1 from the emergency broadcasting power line 15. It is done.

Next, the operation of the illustrated embodiment will be explained.

First, during normal times when AC100V is normal, when a general announcement broadcast signal is sent from the center via the transmission line of the CATV system, it is divided into the broadcast receiving circuit 1 and the control circuit 2 by the distributor 3, and the control circuit 2 Since the front end 11 does not receive the emergency announcement broadcast, the intermediate frequency signal is sent to the IF circuit 12.
is not output to . As a result, since the detection output of the detection circuit 13 cannot be obtained, the logic circuit 14 supplies the power output of the power supply circuit 17 to the general broadcasting power supply line 16.

Therefore, in the broadcast receiving circuit 1, the front end 4 receives power from the power line 16 for general broadcasting and is switched to the receiving mode for general announcement broadcasting, and the gate 10 is also closed to enable volume adjustment using the volume 9. The other circuit sections also receive power from the general broadcast power line 16, and the general announcement broadcast is reproduced and received from the speaker 8.

Next, if an emergency announcement broadcast is sent from the center, the front end 11 of the control circuit 2 outputs an intermediate frequency signal by tuned reception of the emergency announcement broadcast signal, which is amplified by the IF circuit 12 and sent to the detection circuit 1.
3, the detection output is obtained from logic circuit 14.
switches the power output of the power supply circuit 17 to the power supply line 15 for emergency broadcasting, and therefore the front end of the broadcast receiving circuit 1 is connected to the power supply line 15 for emergency broadcasting.
receives power supply as a control signal and switches to tuned reception of the emergency broadcast signal, and when there is no control input to the gate 10, the gate 10 opens, and by bypassing the volume 9, an emergency announcement is made at the maximum volume from the speaker 8. Broadcasting is received and played back.

Next, if a power outage occurs at the terminal, power supply circuit 1
7 becomes zero, the power failure detection circuit 20 generates a power failure detection output, and by closing the internal contacts of the drive circuit 19, the power output of the battery 18 is broadcasted via the power supply line 21 and the emergency broadcast power line 15. Supplied to the receiving circuit 1. Therefore, during a power outage, the broadcast receiving circuit 1 switches to the same reception mode as when receiving an emergency broadcast.

Therefore, even if there is a power outage while the general announcement broadcast is being sent, the broadcast receiving circuit 1 has switched to the emergency announcement broadcast reception mode, so the reception and playback of the general announcement broadcast will not be performed, and the emergency announcement broadcast will not be received and played back. Since the broadcast receiving circuit 1 is placed in a reception standby state, the current consumption of the broadcast receiving circuit 1 is extremely small, and the power consumption of the battery 18 is significantly reduced. Furthermore, a reverse current blocking diode D1 is connected from the battery 18 to the control circuit 2.
is installed, so power is not supplied,
Since the control circuit 2 does not consume battery power, the effect of saving battery power is even greater.

Of course, if the emergency announcement broadcast signal is sent while the battery power is switched to the battery power source, the broadcast reception circuit 1, which has been switched to the emergency announcement broadcast reception mode, receives and reproduces the emergency broadcast at the maximum volume.

Although the control circuit 2 in the above embodiment is configured to tune and receive only the emergency announcement broadcast signal at the front end 11, it may be configured to tune and receive only the general announcement broadcast signal, and in this case. Logic conditions are set so that power is supplied to the general broadcast power line 16 by the detection output of the detection circuit 13, and when the detection output is no longer obtained, the logic circuit 14 can supply power to the emergency broadcast power line 15. All you have to do is set .

(Effect of the invention) As explained above, according to the invention, a general announcement broadcast signal or an emergency announcement broadcast in the event of a disaster, etc. is connected to a transmission line drawn out from the center side and transmitted from the center side. a control circuit having a logic circuit that detects a signal and outputs a control signal based on the detection signal; and a control signal from the logic circuit of the control circuit to switch to a reception mode of either the notification broadcast signal or the emergency notification broadcast signal. A CATV comprising: a broadcast receiving circuit having a speaker for receiving and reproducing broadcast signals; and a power supply circuit for supplying power to the control circuit and the broadcast receiving circuit.
In the announcement broadcasting device, the power supply circuit is provided with a power outage detection circuit for detecting a power outage and a battery for backing up the power in the event of a power outage, and the reception mode of the broadcast receiving circuit is determined by the power outage detection output of the power outage detection circuit. Means is provided for switching to a reception mode for receiving an emergency announcement broadcast, supplying the battery power to the broadcast receiving circuit, and further controlling the broadcast signal from the speaker to be louder than the general announcement broadcast signal. Therefore, in the event of a power outage, the system always switches to the reception mode for emergency announcement broadcasts, and even if general announcement broadcasts are sent from the center, they are not received and played back at the terminal, so power consumption due to battery power can be reduced.

In addition, in the event of a power outage that switches to battery power, the supply of battery power to the control circuit that detects the broadcast mode and switches to the reception mode for general announcement broadcasts and emergency announcement broadcasts is also stopped, which reduces battery power consumption during power outages. The effect is extremely large,
Even if the power outage is prolonged, emergency announcement broadcasts can be surely received and played back using battery power.

[Brief explanation of the drawing]

The figure is a circuit block diagram showing an embodiment of the present invention on the terminal side. 1... Broadcast receiving circuit, 2... Control circuit, 3...
Distributor, 4, 11...Front end, 5, 12
...IF circuit, 6,13...Detection circuit, 7...Audio amplifier, 8...Speaker, 9...Volume,
10... Gate, 14... Logic circuit, 15... Power line for emergency broadcasting, 16... Power line for general broadcasting, 17... Power supply circuit, 18... Battery,
19...drive circuit, 20...power failure detection circuit,
21...Power supply line.

Claims (1)

[Claim for Utility Model Registration] Connected to a transmission line drawn out from the center side, detects a general announcement broadcast signal or an emergency announcement broadcast signal in the event of a disaster, etc., and based on the detected signal. a control circuit having a logic circuit that outputs a control signal; and a control signal from the logic circuit of the control circuit to switch to a reception mode of either the notification broadcast signal or the emergency notification broadcast signal, and to receive the notification broadcast signal and to reproduce the broadcast signal. A CATV announcement broadcasting device comprising: a broadcast receiving circuit having a speaker; and a power supply circuit supplying power to the control circuit and the broadcast receiving circuit, wherein the power supply circuit includes a power outage detection circuit for detecting a power outage. , a battery is provided to back up the power in the event of a power outage, and the power outage detection output of the power outage detection circuit switches the reception mode of the broadcast receiving circuit to a reception mode for receiving emergency notification broadcasts, and the battery power is supplied to the broadcast receiving circuit. An announcement broadcasting device for CATV, further comprising means for controlling the reproduction of the broadcast signal from the speaker to be louder than the general announcement broadcast signal.