SU577469A1 - Arrangement for measuring frequency of three-phase sinusoidal voltage - Google Patents

Claims (1)

The invention relates to electrical measurements and can be used in various measurement systems. A device for measuring the frequency of a three-phase sinusoidal voltage is known, containing a serially connected differentiator and a separating device. The disadvantage of such a device is the limited range of measured frequencies due to the use of a large one. the number of analog devices that require adjustment of several parameters of the circuit. The aim of the invention is to expand the range of measured frequencies. For this purpose, a three-input comparator, a decoder, a key block, a peak detector and a module allocation unit, are introduced into the device for measuring the frequency of a three-phase sinusoidal voltage, containing a series-connected differentiator and a separating device; the inputs of the key block, and the outputs of the comparator through a decoder connected to the control input of the key block, the combined output of which is connected to the input of the differentiator, This input of the peak detector is connected to a first input of the comparator trehvhodovogo and pikoVOG9 detector output is connected to the first input of divider whose output is connected to the input unit vscheleni modulation. FIG. 1 is given a functional diagram of the proposed device; in fig. 2 shows diagrams explaining the operation of the yCD device, where a is the voltage, b, c and d are the comparators output voltages, d, e, g are the decoder output signals, 3 is the output voltage of the keys, and is the voltage to At the input of the differentiator, to - voltage at the output of the dividing device. The device for measuring the frequency of a three-phase sinusoidal voltage contains a gate input comparator 1, deiafrator 2, a block of 3 keys, a differentiator 4, a peak detector 5, a separating device 6, a unit 7 for extracting a module, inputs 8-10 of three-phase voltage, and inputs 8-1О are connected To the corresponding inputs of the comparator 1 and to the controlled inputs of Block 3, the control input of which is connected via a differentiator to the first input of the device 6, the second input of which through the detector 5 is connected to the input 8, and the output is connected via block 7 to the output stroystva for measuring frequency. The device operates as follows: Comparator 1 compares the incoming voltages with each other. The decoder 2. controls the unit 3, which separates the linear portions of the sinusoidal voltages, of which the differential 4 separates the voltage proportional to the derivative of the input voltage function. The peak detector 5 memorizes the amplitude value of the input voltage and controls the divider device 6. The module 7 of the extraction module rectifies the voltage coming from the output of the divider device 6 outputs a voltage proportional to the frequency of the input voltage. The invention The device for measuring the frequency of a three-phase syphilus of a common voltage, containing a successively connected differentiator and a separating device, is due to the fact that, in order to expand the range of measured frequencies, a three-input comparator, a decoder, a key block, a peak detector and the module allocation unit, the comparator inputs are connected to the inputs of the three-phase voltage phases and to the three controlled inputs of the key block, and the outputs of the comparator are connected to the control input through a deshfrator for a block of keys, the combined output of which is connected to the input of the di (1 of the ferentiator, the input of the peak dejector is connected to the first input of the three-input comparator, and the output of the peak detector is connected to the first K: isolation device, the output of which is connected module 5 b Well I / X X  . / X / / cot oot n I I -cot cot Ojt