JPH0543634U - Audio auto monitor - Google Patents

Abstract

(57) [Abstract] [Purpose] A limiting amplifier that attenuates the input audio signal when it is higher than the reference level, and a comparison circuit that detects the mismatch between the attenuated output and the audio signal as input. And an automatic voice monitor including an alarm circuit that outputs an alarm in response to the mismatch output, even when a signal higher than the reference level is input, the failure of each part of the device is correctly detected. When the detection circuit 6 detects that the signal input to the comparison circuit 81 is higher than the reference level, the correction circuit 7 corrects the audio signal according to the attenuation level. [Effect] Even if a signal exceeding the rated level is input and attenuated, since the comparison is performed after correction, a failure in each part can be correctly detected.

Description

[Detailed description of the device]

[0001]

【Technical field】

 The present invention relates to an automatic audio monitor, and more particularly to an automatic audio monitor for a broadcaster provided on the broadcast station side.

[0002]

[Prior art]

 Generally, this type of automatic audio monitor is used to detect a failure of a modulator, etc., by comparing a voice signal as a reference input, a signal that is modulated and demodulated again and used as a comparison input. Was there. That is, as shown in FIG. 4, the reference input 1 was modulated by the modulator 200 via the limiting amplifier 100 and then transmitted to the outside. The modulated signal was demodulated by the demodulator 300 and applied to the monitor circuit 400 as the comparison input 2.

That is, in the monitor circuit 400, the reference input 1 and the comparison input 2 are compared, and the failure of the modulator 200 or the like is detected by comparing the levels of both inputs. If they do not match, an alarm output 13 is sent out, and each modulator etc. is switched from the active mode to the standby mode. In this way, by constantly monitoring the reference input 1, it is possible to continue the broadcasting service without any trouble even when each part of the device fails.

Here, in the conventional monitor circuit, as shown in FIG. 3, the reference input 1 is amplified by the amplification circuit 31, and the comparison input 2 is amplified by the amplification circuit 32. The signals were compared in level by the comparison circuits 81 and 82. When both comparison results show a mismatch, a mismatch output is sent from both comparison circuits, but only one of them is delayed by the activation delay circuit 9 and the clock input to the bistable circuit (FF) 10 is performed. Become. Therefore, when the comparison result shows a mismatch, the bistable circuit 10 holds the fact of the mismatch. Then, the alarm output 13 is sent from the alarm circuit 12.

The delay circuit 11 is provided to have a certain confirmation time in order to prevent malfunction.

That is, in the conventional monitor circuit, the respective signals that have passed through the two amplifier circuits are compared under the condition that the audio signal is within the rated level. If the level difference between the two is abnormal, the abnormality is held by the startup delay circuit 9, the bistable circuit 10 is passed, and the delay circuit 11 for preventing malfunction is provided with a certain confirmation time. After that, the alarm circuit 12 is operated to send an alarm to the outside.

Here, referring again to FIG. 4, in the present broadcasting system, a limiting amplifier 100 for audio signals is provided. The limiting amplifier 100 is for attenuating an input audio signal by a predetermined level (for example, 10 dB) when the audio signal is higher than a reference level (rated level).

Therefore, under the condition that the audio signal is within the rated level, the signal levels of the reference input 1 and the comparison input 2 are compared as they are, and when the level of the comparison input falls below a certain level from the reference input, it is determined that the audio signal is abnormal. Detected. Then, the abnormality is retained, and if the abnormality continues even after the confirmation time has elapsed, the alarm is sent to the outside normally.

However, when a voice signal exceeding the rated level is inputted, the response level of the limiting amplifier 100 is affected, and the signal level on the comparison input 2 side, which is the output side of the limiting amplifier 100, momentarily drops. Therefore, there is a drawback that it causes a malfunction that is detected as an abnormality.

[0010]

[The purpose of the device]

 The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to provide an automatic voice monitor that correctly detects a failure even when a voice signal exceeding a rated level is input. ..

[0011]

[Device configuration]

 The automatic voice monitor according to the present invention uses a limiting amplifier that attenuates a predetermined level of an input voice signal when the input voice signal is higher than a reference level, and inputs the attenuated output and the voice signal to detect a mismatch between the two. And an audio automatic monitor having a means for outputting an alarm in response to the disagreement output, wherein when the audio signal input to the comparing means is higher than the reference level, the audio signal is It is characterized by including a correction means for correcting according to a predetermined level.

[0012]

【Example】

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of a monitor circuit in an automatic voice monitor according to the present invention, and the same portions as those in FIG. 3 are designated by the same reference numerals. In the figure, the monitor circuit of this embodiment has a configuration in which a detection circuit 6 and a correction circuit 7 are added to the circuit of FIG.

The detection circuit 6 and the correction circuit 7 have a function of correcting the reference input input to the comparison circuit 81 by a predetermined level attenuated by the limiting amplifier, and when there is an input exceeding the rated level. Only, the correction is applied to the reference input like the limiting amplifier. As a result, when the input is within the rated level, the reference input 1 and the comparison input 2 are compared as in the conventional operation, and when the input exceeds the rated level, the level attenuation characteristic of the limiting amplifier is adjusted. After the reference input is corrected, it will be compared with the comparative input 2.

Here, the detection circuit 6 compares the reference level attenuated in the limiting amplifier with the reference input 1 and, when the reference input exceeds the reference level, outputs to that effect to the correction circuit 7. In this case, the detection circuit 6 is configured so that its reference level can be arbitrarily set in consideration of the amplification factor of the amplification circuit 31.

The correction circuit 7 is responsive to the detection output of the detection circuit 6 to correct the reference input 1 according to the attenuation characteristic of the limiting amplifier, that is, the attenuation level. In this example, the level is corrected as an analog signal.

In such a configuration, the audio signal of the reference input 1 is amplified by the amplifier circuit 31 with a constant value. On the other hand, the audio signal of the comparison input 2 is also amplified by the amplifier circuit 32 at a constant value.

Both the amplified voice signals of the reference input and the comparison input are input to the comparison circuits 81 and 82. Here, if the detection circuit 6 is appropriately set, the reference input is detected, and the correction circuit 7 corrects the comparison circuit 81.

When there is a level difference between the reference input and the comparison input that exceeds the specified level, the output signal from the comparison circuit 81 passes through the start delay circuit 9, the bistable circuit 10 operates, and that fact is held. It Moreover, after the abnormality confirmation time is set in the delay circuit 11, the alarm circuit 12 operates and an alarm is output to the outside.

As a result, when the modulator or the like fails, the working mode and the standby mode are switched.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, parts equivalent to those in FIGS. 1 and 3 are indicated by the same reference numerals.

In this example, unlike the first example (FIG. 1), sampling circuits 41 and 42 and quantization circuits 51 and 52 are provided in the preceding stage of the comparison circuit. In other words, these circuits convert the audio signals of the reference input 1 and the comparison input 2 into digital values and then compare them.

In such a configuration, the audio signal of the reference input 1 is amplified by the amplifier circuit 31 to a constant value. The output is sampled by the sampling circuit 41, quantized by the quantization circuit 51, and input to the comparison circuits 81 and 82. Further, the detection circuit 6 is appropriately set, and the comparison circuit 81 is corrected by the correction circuit 7.

Similarly, the audio signal of the comparison input 2 also passes through the amplifier circuit 32, the sampling circuit 42, and the quantizing circuit 52, and is input to the comparison circuit 82.

When there is a level difference between the reference input and the comparison input in both comparison circuits that is greater than the specified level, the signals from the comparison circuits 81 and 82 are passed through the start delay circuit 9 to operate the bistable circuit 10. That fact is retained. Further, after the abnormality confirmation time is set in the delay circuit 11, the alarm circuit 12 is activated and an alarm is output to the outside.

As a result, when the modulator or the like fails, the working mode and the standby mode are switched. In this example, since the audio signals are compared with each other by digital values, the correction value in the correction circuit 7 is also a digital value.

As described above, since the detection circuit 6 capable of comparing and detecting the reference input with an arbitrary value and the correction circuit 7 for correcting the reference input are added, in a broadcasting system including a limiting amplifier for audio signals. Even if an audio signal exceeding the rated level is input, it is possible to prevent malfunction by correcting the reference input input to the comparison circuit with a correction value according to the attenuation characteristics of the limiting amplifier.

Generally, in the limiting amplifier of the audio signal, there is a time lag (attack time) between the input level exceeding the reference level and the actual suppression of the level by the attenuation process, and the level becomes lower than the reference level again. There is also a time lag from when the damping process is actually canceled (recovery time). The malfunction caused by these time lags can be avoided by performing the correction processing as in the present invention.

[0029]

[Effect of the device]

 As described above, the present invention has an effect that a failure of a modulator or the like can be correctly detected by correcting a signal of rated input over according to the attenuation characteristic of the limiting amplifier.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an automatic audio monitor according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a main part of an automatic voice monitor according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a main part of a conventional audio automatic monitor.

FIG. 4 is a block diagram showing a configuration of a broadcasting system including an automatic audio monitor.

[Explanation of symbols]

 6 Detection circuit 7 Correction circuit 81, 82 Comparison circuit

Claims (1)

[Scope of utility model registration request] 1. A limiting amplifier that attenuates a predetermined level of an input audio signal when the input audio signal is higher than a reference level, and a comparison unit that receives the attenuated output and the audio signal as input and detects a mismatch between the two. A voice automatic monitor having means for outputting an alarm in response to the mismatch output,
An automatic audio monitor, comprising: a correction unit that corrects the audio signal according to the predetermined level when the audio signal input to the comparison unit is higher than the reference level.