SU394948A1 - DEVICE FOR AUTOMATIC CONTROL OF LEVEL OF BROADCAST SIGNAL - Google Patents

Description

one

The level of the broadcast signal must be monitored, since the cause of the absence of a sound program for a user over 0.5 -: - min may be a violation of the integrity of the communication channel. A systematic decrease in the level of the sound program leads to non-modulation of the transmitters and, consequently, to a decrease in the zone of reliable reception of the program of hanging by listeners. An overestimation of the sound program. We cause distortion of the transmitted signal, overload of the long-distance veni-1 channels, over-modulation of the transmitter and may cause the transmitter to lock and turn off, which causes a technical stop.

A multi-channel sound program level indicator 1 is known, which is designed to automatically control the reduction of the sound program signal level corresponding to a predetermined depth of modulation. The disadvantage of such signaling devices is the low accuracy in determining the time for reducing the sound program level due to the fact that the source of pulses is not synchronized with the response time of the threshold device. This leads to the fact that every time the time between the time the threshold element is triggered and the next time the counting pulse from which

2

counting varies. Consequently, each time B is read by a random error, which leads to false positives. With a pulse interval of 2 minutes, the error can be significant.

To increase accuracy, one can increase the frequency of the following npulses, but for this it is necessary to considerably complicate the untraceable scheme. Such a recalculation scheme is unsuitable for signaling the disappearance of the broadcast signal, since according to the technical operation rules, the time interval, and which a program may be absent, must not exceed 1 minute, on the program "M k - 20 s.

In addition, signaling devices are unreliable in operation due to the use of relay windings as threshold elements, as well as due to the use of a common source of read pulses for all channels. When the system fails to function or if the latter fails to operate, the monitoring devices of all channels are idle, i.e., the error is introduced into the operation of all alarms simultaneously for each channel monitored.

To improve the control accuracy and reliability in the proposed device, the monitored broadcast signal is fed through an isolating amplifier to a quasi-peak detector, to the output of which is connected a nara. There are actually three control circuits that allow you to control the overestimation, understatement and interruption of the broadcast signal, which include contactless threshold elements and alarm devices for every single cable; Between the outputs of loregovy elements and devices of the cut-off signal; in the control circuit of the underestimate and loss of the signal are switched on by a helper time relay and coincidence circuit, the second input of which is connected to the output of the threshold elements, and in the case of the monitoring of the height error (the Signal is a non-resistive node, the second input of which is A memory element and a time relay is connected to the output of the threshold element, the time relay is simultaneously connected to the second input of the memory element.

The drawing is a block diagram of the described device. A control signal is transmitted through an isolating amplifier / to a quasi detector 2, and the detuned voltage from which the inputs of the three contactless threshold elements 5–5 are simultaneously applied, respectively, in the circuit of the broadcast signal, the signal being lowered and overestimated. The control of iropadia and underestimation is similar in construction and principle, only the response levels of the threshold elements 5 and - / and the time delay of the relay 5 and 7 are different. Under the disappearance of the device, the norm is adopted, at which within 1.5 minutes (and on the program “Ma to 0.5 AIUH”) the value of the broadcast signal does not exceed 5% (-26 dB) from the commanded maximum level. Under the auspices of the adopted porma, for which for 6 min the value of the broadcast sigal does not exceed 70% (-2.5 dB) of the peak maximum level. In accordance with the indicated norms, time relay 6 is set for a time of 1.5 minutes (with the possibility of switching to 0.5 minutes), and time relay 7 is set to 6 minutes.

When triggered from threshold elements 3 and 4, the signals triggering the relay are output.

6 and 7 times. At the same time, these signals are sent to coincidence circuits 8 and 9. According to the specified shutter speed. Relay time 6 and

7 emit signals of the diagrams 8 and 9, from which, in turn, the signals are sent to the devices 10 and II of the alarm signal “disappearance and underestimate,” respectively.

If during the counting time of the corresponding time relay a broadcast signal appears with a level exceeding the triggering threshold of threshold elements 3 and 4, then the output of the latter receives the "reset" signals, which return the relay 6 and 7 of time to the initial position. In this case, the output signals do not arrive at the JO and P alarm devices.

Threshold element 5 of the overestimate control signal circuit triggers

at the time of the maximum level of the sigpal (above 58% it is iomially about the value of} and, J-4 to). CiiTiia: i, from element 5, enters an elem. Memory 12 memory that triggers the time relay / J and prevents further transmission of signals from element 5. Simultaneously from element 5, the signal enters the intersecting circuit 14, and it is an alarm device 15 only after

The following four different pulses from element 5 for the 1P1 time interval, determined pe.ie 13, corresponding to 1 min. s .1; e1 is the time for the first 1; ; yulsa For 1 minute with relay

From the time on the circuit 14, a sigal reset occurs, returning it to its original state. Simultaneously, the signal "reset; returns the memory element 12 to the initial youth state, and with which it emiles

the threshold element 5 starts the relay 13 time with i 1 and.

Thus, if during the time interval, equal to 1 min, there will be more than three overestimation pulses, the device / 5 alarm is triggered

alarm "overestimate.

The synchronous start of the relay is 6, 7, and 13 times from the moment the threshold elements are triggered by the 3 rd controller, which improves the accuracy of timing and can set any necessary time delay depending on the operating conditions.

Introduction of coincidence circuit diagrams 8 and 9 for monitoring the loss and understatement of signals, interworking circuit 14 and memory element 12

eliminates the occurrence of false flooring, increases the reliability of the Coptrol and the reliability of the device.

PREDETE H and o about the and with and

Device for automatic coitrol broadcasting signal level, containing a series-connected amplifier and quasi-detector detector, to the output of which

Three parallel measuring circuits for coitrol overstatement, underestimation of broadcasting, and correspondingly, each consisting of a porot element and an alarm device, characterized in that, in order to increase the accuracy of coitrol and reliability, between the threshold element output and the dimension and the dimension and the dimension and the reliability of the coitrol. Measuring circuit for coitrol underestimating and npoina broadcasting signal are connected in series additionally introduced time relays and an integrated circuit, to the second input p Latter ele.menta connected to the output of the threshold, and in the measuring target for koptrol inflated broadcast signal between vyhodo.m norogovogo ele.menta and v.hodo.m corresponding alarm device is connected additionally introduced pereschet1 first node, whose second input

through ios ;;; divisio connected elements

memory and time relay connected to the output of the threshold element, while the relay output

time ;;: also connect to the second input of e.chemenga us / gp ;.