SU799152A2 - Device for stabilizing mean frequency of noise over- and undershoots - Google Patents

Description

(54) DEVICE TO STABILIZE THE MEDIUM FREQUENCY OF UIVMOBblX EMISSIONS

The quantizer 1 level. The output of the quantizer 1 is connected through a prohibition element 6 to the summing input of the reversible counter 4, in which the subtracting input is connected to the output of the generator 5, and the outputs are connected to the control inputs of the attenuator 3. The output of the differentiating unit 7 is connected via threshold element 8 to the prohibitive input of the prohibition element 6.

The device works as follows.

From the input signal of the noise signal, the driver 2 generates a voltage of 6m (t), which is an estimate of the effective value of the input noise. The voltage from the output of the imaging unit 2 is fed to the input of a digital controlled attenuator 3, the transmission coefficient h of which is determined by the digital code received from the outputs of the reversible counter 4 to the control inputs of the attenuator 3. The output voltage of the attenuator 3 is fed to the input of the threshold level adjustment of the quantizer 1. In addition, the voltage from the output of the imaging unit 2 is fed to the input of the differentiating unit 7. If the intensity of the noise signal is constant, then the output voltage of the differentiating unit 7 does not exceed With the first level of the threshold element 8 with a high probability, which is achieved by appropriate selection of layer C. The output signal of the threshold element 8 is absent and prohibition element 6 passes pulses from the output of quantizer 1 to a summing input of the counter 4.

At the same time, the noise signal is fed to the input of the quantizer 1, in which binary amplitude quantization of the input signal is performed. Standard-amplitude pulses from the output of the quantizer 1, corresponding to emissions of the noise signal above the threshold level, arrive at the summing input of the reversible counter 4. The counters 4 subtractive input receives pulses from the output of the generator 5, the frequency of which F is equal to the specified average frequency exceeding the threshold noise level. In a reversible counter 4, a comparison is made of the actual average emission frequency with a given frequency FY. If the average frequency of the Hs1d noise emissions by the threshold level increases (decreases), then the contents of counter 4 also increases (decreases). At the same time, the transmission coefficient h of the a-tenuator 3 increases (decreases) and, accordingly, the threshold levels in the quantizer 1 increase (decrease), which leads to a decrease (increase) in the average frequency of noise emissions at the output of the quantizer 1.

If the intensity of the output noise increases dramatically, then the output voltage of the differentiating unit 7 exceeds the threshold level C of element 8 and a voltage appears at its output {passing from the output of the quantizer 1 through the inhibit element 6. After the driver 2 A transition process caused by a change in the intensity of the input noise is triggered, the voltage at the output of differentiating unit 7 becomes less than the threshold level of element 8, and the prohibition element b again starts to pass pulses from the output of quanta bodies 1 to the input of counter 4. In this case, the overshoot error is reduced due to the fact that with a sharp increase in noise intensity, until shaper 2 forms a new estimate of noise intensity, a series of emissions with an average frequency much higher than a given frequency FJ appears at the output of quantizer 1 .

With a sharp decrease in the intensity of the input noise, the average frequency of emissions decreases and the overshoot error does not occur, since the period of the pulse of the generator 5 in a properly designed device is several times longer than the time constant of the former 2 O (| of the effective value).

The use of new elements, a differentiating unit, a threshold element and a prohibition element favorably distinguishes the proposed device from the known one, since the overshoot error decreases with a sharp increase in the input noise intensity, which allows increasing the accuracy of stabilization of the average frequency of noise emissions.

Claims (1)

1. USSR author's certificate No. 633146, cl. H 04 B 1/10, 1977.