JPH06124393A - Control signal sound output preventing circuit - Google Patents

Abstract

PURPOSE:To provide the control signal sound output preventing circuit which prevents a control signal sound from being outputted even when the control signal is variable in length and also shorten a delay time as to a control signal sound output preventing circuit which prevents a control signal sound from being outputted from a speaker when the speaker amplifier of a controlled station of a water discharge warning system is turned ON. CONSTITUTION:A received signal is inputted to the speaker amplifier through delay circuits 1 which delays the signal by the period of time of the synchronous detection of the control signal and a switch 2. Further, the circuit is provided with a synchronism detection signal output circuit 3 which outputs a signal turning OFF the switch 2 once detecting synchronism from the received control signal and a carrier break detection delay circuit 4 which outputs a signal turning ON the switch 2 by delaying the synchronism detection time once detecting a carrier break of the received control signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a control signal sound output prevention circuit for preventing a control signal sound from being output from a speaker when a speaker amplifier of a controlled station of a discharge warning system is turned on.

FIG. 4 is a time chart when a speaker amplifier of a controlled station is turned on as an example. In the discharge warning system, when water is discharged from a dam, etc., the control station sends a control signal to the controlled station, turns on the speaker amplifier of the controlled station, and sends the discharge warning sound signal from the control station to the controlled station. The sound of the release warning is output from the speaker to inform nearby residents.

The frame format of the control signal is shown in FIG.
As shown in (C), the synchronization bit area, the synchronization flag area,
It consists of a station address area, a control area, a control information area, a check bit area, and a synchronization flag area, and the length of the control information area can be changed. For example, at a data transmission rate of 200 bps, normal control is possible. The signal time is 400 ms, and the synchronization time is about 80 ms.

The speaker amplifier of the controlled station is turned on for the case of turning on the speaker amplifier of one controlled station shown in FIG. 4A and for the simultaneous broadcasting shown in FIG. 4B. And when turning on the speaker amplifiers of all controlled stations and 2
There is a street.

In the case of (A), as shown in (a),
A start signal is sent from the control station to the controlled station, and the speaker amplifier of the controlled station is turned on as shown in (c). At this time,
As shown in (b), the controlled station sends a confirmation signal that the speaker amplifier is turned on to the control station, and when the control station receives the confirmation signal, as shown in (a), the release warning sound signal and the continuous broadcast are sent. A stop control signal is sent and the speaker amplifier is turned off as shown in (c).

In the case of the simultaneous broadcasting shown in (B), a simultaneous activation signal is sent from the control station to all controlled stations as shown in (d), and a speaker amplifier of all controlled stations is sent as shown in (g). Is turned on, and then, as shown in (e), a monitoring control signal is sent from the control station as to whether the speaker amplifier is turned on, and (f)
As shown in (4), all controlled stations transmit to the control station a confirmation signal that the speaker amplifier is turned on, and when the control station receives this signal, as shown in (e), the discharge warning sound signal and the continuous broadcast stop control signal are sent. To turn off the speaker amplifier as shown in (g).

In this case, if the sound of the control signal shown in (A) and (a) and the sound of the supervisory control signal and control signal shown in (B) and (e) are output from the speaker, it will be offensive to the ears, so this output is prevented. However, even if the control signal has a variable length, it is desired to provide a control signal sound output prevention circuit which can reduce the output delay of the discharge warning sound signal.

[0008]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional control signal sound output prevention circuit, and FIG. 6 is a time chart of each section of FIG.

In FIG. 5, the discharge warning voice signal and the control signal reception signal shown in FIG. 6A and FIG. 6D in the case of simultaneous broadcasting are branched into two by the hybrid circuit 5, and the delay circuit 10 is provided.
And the carrier loss detection unit 4-1.

In the delay circuit 10, the signal is converted into a digital signal, delayed by the time of the control signal as shown in (b) and (e) of FIG. 6, converted into analog, and input to the analog switch 2. Incidentally, the control signal is 0, 1 or, for example, FSK in which the carrier is 1700 Hz and 1700 ± 400 Hz.
It is a modulated signal.

On the other hand, in the carrier break detection section 4-1 (a)
When the carrier disconnection of the control signal and the monitoring control signal shown in (d) is detected, the signal is sent to the set terminal of the flip-flop (hereinafter referred to as FF) 12 and the delay circuit 11, and the FF 12 sends the signal to the analog switch 2 from the output. , (C)
As shown in (f), the signal is turned off so that the input signal is not sent to the speaker amplifier, the delay circuit 11 delays it by the time of the control signal and sends it to the reset terminal of the FF12, and the FF12 sends the signal from the output to the analog switch 2, c)
As shown in (f), it is turned on and the input signal is sent to the speaker amplifier.

In FIG. 6, the release warning voice signal and the subsequent broadcast stop control signal in the case of simultaneous broadcasting are shown in (a).
It is omitted because it is the same as that shown in (b) and (c). That is, the control signal shown in (a) and the monitor control signal shown in (d) are not sent to the speaker amplifier, and the control signal sound and the monitor control signal sound are not output from the speaker.

[0013]

However, in the control signal sound output prevention circuit described above, the output of the control signal sound can be prevented unless the control signal length changes, but it is not possible to cope with the case where the control signal has a variable length. There is a problem in that it is not possible, and the delay time is long, for example, 400 ms of the control signal time, and the distortion of the discharge warning voice signal becomes large.

An object of the present invention is to provide a control signal sound output prevention circuit which can prevent the output of the control signal sound and reduce the delay time even when the control signal has a variable length.

[0015]

FIG. 1 is a block diagram showing the principle of the present invention. As shown in FIG. 1, the reception signal is input to the speaker amplifier through the delay circuit 1 and the switch 2 which delay the time for detecting the synchronization of the control signal, and when the synchronization is detected from the reception control signal, the switch 2 is turned on. A sync detection signal output circuit 3 for outputting a signal for turning off and a carrier break detection delay circuit 4 for outputting a signal for turning on the switch 2 after delaying the sync detection time when a carrier break of the reception control signal is detected are provided. The configuration.

[0016]

According to the present invention, the delay circuit 1 delays the received signal by the time for detecting the synchronization by the synchronization bit of the control signal.
And to the speaker amplifier via the switch 2, and also to the sync detection signal output circuit 3 and the carrier break detection delay circuit 4.

The synchronization detection signal output circuit 3 outputs a signal for turning off the switch 2 when synchronization is detected by the synchronization bit of the control signal, and the carrier disconnection detection delay circuit 4 detects synchronization when the carrier disconnection of the control signal is detected. A signal for delaying the time and turning on the switch 2 is output.

That is, the received signal is delayed only for the synchronization detection time of the control signal, the switch 2 is turned off when the synchronization of the control signal is detected, the carrier disconnection of the control signal is detected, and the switch 2 is delayed after the synchronization detection time is delayed. Is turned on to prevent the control signal sound from being output from the beaker, so it can be prevented even if the control signal has a variable length, and the release alarm sound signal is delayed only by the control signal synchronization detection time. Distortion can be reduced.

[0019]

2 is a block diagram of a control signal sound output prevention circuit according to an embodiment of the present invention, and FIG. 3 is a time chart of each part of FIG.

In FIG. 2, the discharge warning voice signal and the control signal reception signal shown in FIG. 3 (a) and (e) in the case of simultaneous broadcasting are branched into two by the hybrid circuit 5, and the delay circuit 1 and the carrier signal. It is input to the disconnection detector 4-1 and the demodulation circuit 6.

In the delay circuit 1, the signal is converted into a digital signal, delayed by the synchronization detection time as shown in FIGS. 3B and 3F, converted into analog, and input to the analog switch 2. In the demodulation circuit 6, the FSK-modulated control signal is demodulated, input to the synchronization detection circuit 3-1, and the synchronization bit of the control signal shown in FIG. Then, the signal is input to the set terminal of the FF7, and the output of the FF7 turns off the analog switch 2 as shown in FIGS.

In the carrier disconnection detecting section 4-1, FIG.
As shown in (g), when the carrier break of the control signal is detected, the delay detection time is delayed by the delay circuit 4-2 (for example, 80 ms), input to the reset terminal of FF7, and output from FF7. ) Analog switch 2 as shown in (h)
To turn on.

In FIG. 3, the broadcast warning sound signal and the subsequent broadcast stop control signal in the case of simultaneous broadcasting are shown in (a).
Since it is the same as shown in (b), (c) and (d), it is omitted. That is, the discharge warning voice signal is delayed only for the control signal synchronization detection time (for example, 80 ms), and the distortion can be reduced. Further, the analog switch 2 is turned off only when the control signal synchronization is detected. Since the analog switch 2 is turned on when the synchronization detection time is delayed after the carrier break of the control signal is detected, even if the control signal has a variable length, the output of the control signal sound from the beaker can be prevented.

[0024]

As described in detail above, according to the present invention, even when the control signal has a variable length, the output of the control signal sound from the speaker can be prevented, and the delay of the discharge warning sound signal is shortened, so that the distortion is distorted. There is an effect that can reduce.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention,

FIG. 2 is a block diagram of a control signal sound output prevention circuit according to an embodiment of the present invention,

FIG. 3 is a time chart of each part of FIG.

FIG. 4 is a time chart when the speaker amplifier of the controlled station in one example is turned on,

FIG. 5 is a block diagram of a conventional control signal sound output prevention circuit,

FIG. 6 is a time chart of each part of FIG.

[Explanation of symbols]

 1, 4-2, 10, 11 are delay circuits, 2 are switches and analog switches, 3 is a sync detection signal output circuit, 3-1 is a sync detection circuit, 4 is a carrier loss detection delay circuit, and 4-1 is a carrier loss A detection unit, 5 is a hybrid circuit, 6 is a demodulation circuit, and 7 and 12 are flip-flops.

Claims (1)

[Claims] 1. A control signal sound output prevention circuit for preventing a control signal sound from being output from a speaker when a speaker amplifier of a controlled station of a discharge warning system is turned on, and detects a received signal and a control signal synchronously. A synchronization detection signal for inputting to the speaker amplifier through the delay circuit (1) and the switch (2) for delaying the time, and outputting a signal for turning off the switch (2) when synchronization is detected from the reception control signal. An output circuit (3) and a carrier loss detection delay circuit (4) for outputting a signal for delaying the synchronization detection time when the carrier loss of the reception control signal is detected and turning on the switch (2) are provided. Control signal sound output prevention circuit.