SU932627A1 - Device for automatic monitoring of parameters of voice-frequency dialling frequency signals - Google Patents

Description

(54) DEVICE FOR AUTOMATIC CONTROL PARAMETERS OF THE FREQUENCY SIGNALS OF THE DIAL KIT

one

The invention relates to a telephone communication technique and can be used to control the parameters of the frequency signals of a tone dialing.

A device is known for automatically monitoring the parameters of the frequency signals of a tone set, comprising first and second detection units and a band-pass filter combined at the input, the output of which, through an amplifier-detector, the second input of which is connected to the second detection output, is connected to the first input of the blocking unit the third inputs of which are connected respectively to the output of the signal duration meter and to the output of the first threshold unit, the first input of which is combined with the first input of the second nopoio of the block, the second inputs of the first and second threshold blocks are respectively inputs of the first and second reference signals 1 ..

A disadvantage of the known device is the relatively low accuracy of control of the amplitude and duration of the input signal.

The goal of the invention is to increase the accuracy of control by independently measuring the duration and amplitude of the signal.

This goal is achieved by the fact that in the device for automatic control of the parameters of the frequency signals of the tone dialing, comprising the first and second detection units and

10 filter, the output of which through an amplifier-detector, the second input of which is connected to the output of the second detection unit, is connected to the first input of the block, the second and third inputs of which are connected respectively to the output of the signal duration meter and the output of the first threshold unit, the first input of which combined with the first input of the second threshold unit, and the second inputs of the first and second threshold

Claims (1)

The I blocks are respectively the input of the first and second reference signals, the amplifier and the third threshold unit are connected in series, and the output of the first detection unit is connected to the input of the amplifier, the output of the second detection unit is connected to the first input of the second threshold unit, the output of which is connected to the fourth input of the blocking block, and the output of the third threshold block, the second input of which is the input of the third reference signal, is connected to the input of the signal duration meter. The drawing shows a structural electrical circuit of the device. The device contains a band-pass filter 1, amplifier-detector 2, block 3, a signal meter 4, threshold blocks b and 6, blocks 7 and 8 of the detection amplifier 9 and threshold block 10. The device works as follows. The input signal is fed simultaneously to the inputs of the blocks. 7 and 8 of the detection and the input of the band-pass filter 1. The signal amplitude at the output of the band-pass filter 1 is determined by the degree of coincidence of its tuning frequency and the frequency of the input signal. The input signal amplitude is monitored by comparing the rectifier input voltage rectified in block 8 of the input signal with the reference voltage Usch and Un2 corresponding to the maximum and minimum allowable values of the input signal amplitude. This comparison is carried out in the threshold blocks 5 and 6. In addition, the output of the detection unit 8 is connected to the supply point of the voltage supply UPS amplifier-detector 2, the output signal of which can only be seen if the frequency difference between the input signal and the frequency settings bandpass filter 1 will not exceed the specified value. In this case, the amplitude of the output signal of the band-pass filter 1 is larger than the value of the reference voltage Una-. As the amplitude of the input signal increases, the value of the reference voltage Una also increases. Thus, the trigger band of amplifier-detector 2 does not depend on the level of the input signal. The main difference of the proposed device from the known one is that the offline device has an autonomous signal length monitoring circuit. The input signal is rectified in the detecting unit 7 and through the amplifier 9 is fed to the input of the threshold unit 10, where it is compared with the reference voltage Un4. Since the output signal of the detecting unit 7 is no longer used to control the signal amplitude, the time constant of the detecting unit 7 can be chosen very small, with the result that the voltage drop across the output of the threshold unit 10 in duration will correspond to 1 input signal duration with a high degree of accuracy . The control of the amplitude of the input signal is carried out by comparing the output signal of the detecting unit 8 with the reference voltages Usch and Upa in the threshold blocks 5 and 6. In the proposed device, the accuracy of controlling the amplitude of the signal is also improved, since a high degree of smoothing can be realized in the detecting unit 8 pulsations (time constant), which is possible because none of the output signals of the threshold blocks 5 and 6 use the qi of the control of the duration of the input signal. Thus, in th amplitude control device improved accuracy and duration frequency signa / touchtone gov. Apparatus of the Invention A device for automatically monitoring parameters of a tone set of frequency signals, comprising first and second detection units and a band-pass filter combined at the input, the output of which is through an amplifier and the second input is connected to the output of the second detection unit. The second and third inputs of which are connected respectively to the output of the signal duration meter and to the output of the first threshold block, the first input of which is combined with the first input of the second threshold block, and the second inputs of the first and second threshold blocks are respectively the inputs of the first and second reference signals, It was found that, in order to increase the control accuracy by independently measuring the duration and amplitude of the signal, a series-connected amplifier and a third threshold unit were introduced, with the output The first detection unit is connected to the input of the amplifier, the output of the second detection unit is connected to the first input of the second threshold unit, the output of which is connected to the fourth input of the blocking unit, and the output of the third threshold unit, the second input of which is the third reference signal, is connected to the input of the duration meter signal. Sources of information taken into account in the examination 1. USSR author's certificate №573890. cl. H 04 Q 1/46, 1976 (prototype.