SU622018A1 - Harmonic signal frequency meter - Google Patents

Description

one

This invention relates to a measurement technique.

A device for measuring the frequency of a harmonic signal containing two trigger elements, logic gates PI and OR, a trigger, a level separator, a pulse shaper, a filter are known

The disadvantage of this device is insufficient accuracy.

The closest to the technical essence of the invention is a device containing a crossover imimuls shaper, the first input of which is connected to the bus of the measured signal, the second input is connected to the switch of the threshold levels, the inputs of which are connected to the outputs of the output register, the inputs of which are connected with the outputs of the pulse counter, the input of which is connected to the output of the logic element And, the first input of which is connected to the output of the pulse shaper of the crossing of the threshold level, a second input connected to the output time switch connected through the pulse generator to the control input of the output register.

This device also does not provide sufficient accuracy.

The aim of the invention is to increase accuracy.

The goal is achieved by the fact that the device containing the pulse shaper of the intersection of the threshold level, the nerve input of which is connected to the thickness of the measured signal, the second input is connected to the switch of the threshold levels, the inputs of which are connected to the outputs of the output register, the inputs of which are bitwise connected to the outputs of the pulse counter whose input is connected to the output of the logic element PI, the first input of which is connected to the output of the pulse shaper across the threshold level, and the second input to the output of the time relay, The I-IJIH logic element, thrunger, recalculation unit and delay switch, connected between the output of the pulse shaper and the control input of the counter, are inputted via the driver of NMR pulses to the control input to the output register, and connected to the first input of the pulse shaper control input. trigger and directly with the first input of the OR logic element, the second input of which is connected to the command signal bar and the second input of the trigger, and the output of the latter is connected to the third input of the logic element that I.

The structural electrical circuit of the described device is shown in the drawing.

The device contains a driver of 1 threshold level crossing pulses, an OR 2 logic element, an AND 3 logic element, a pulse counter 4, a delay block 5, an output register 6, a threshold level switch 7, a time relay 8, a pulse driver 9, a recalculation block 10, a trigger 11 A measurable signal was applied to bus 12, and a command signal to bus 13. The output signal is removed from the output register outputs 14, 15.

The principle of operation of the described device is as follows.

The input measured signal via bus 12 is sent to shaper 1 pulse crossing the normal level, and the command signal through bus 13 to the logic element OR 2 and trigger I. The output pulses of shaper 1 pulse crossing threshold level through an open trigger AND logical element AND 3 arrive at counter 4 pulses, which counts their number over time, set by relay 8 time. At the end of the signal of the time relay 8, the AND 3 logic element is closed, the pulse shaper 9 generates a pulse, which is fed to the recalculation unit 10, the control input of the output register 6, the logic element OR 2 and through the delay unit 5 - the input of the initial state counter 4 pulses. At that, the switch 7 of the threshold levels 7 in accordance with the output code of the output register 6 specifies the threshold level at which the next measurement cycle will be carried out, and the output pulse of the driver of the 9 pulses through the logical element OR 2 starts the time relay 8.

Thus, the measurement cycles are repeated with the truncated threshold levels of the formation of the counting pulses until the recalculation unit 10 triggers, the output impulse of which overturns the trigger 11.

The device makes it possible to increase the accuracy of measuring the frequency of the harmonic signal against the background of broadband noise, since with successive measurements with more precise normative levels, the error is reduced due to the influence of noise.

Claims (2)

Invention Formula A device for measuring the frequency of a harmonic CNG containing a pulse level crossing pulse shaper, the first input of which is connected to the bus of the measured signal, the second input connected to the output of the non-switch threshold levels, the inputs of which are connected to the outputs of the output register, the inputs of which are bitwise connected from the output: 1 and the pulse counter, the input of which is connected with the output of the log {r-1 element And, the first input of which is connected to the output of the form-1; the pulse signal of crossing the threshold level, the second input of the logical element And is connected to the output of the time relay, and pulse generator)) pulses - to the control input of the output register, a spike of command signals, characterized in that, in order to improve the measurement accuracy, a logical element OR is introduced into it, a trigger, a recalculation unit, and a delay unit, switched on by the output of the driver of the NMR pulses and the input of the counter control, while the output of the pulse shaping device is connected via the converter with the first trigger input and directly from the first input of the OR logic element, the second input of which is connected to the command signal bus and the second trigger input, and the output and the last input to the third input of the logic element I. Sources of information taken into account during the examination 1. USSR author's certificate N ° 398881, cl. G 01R 23/00, 01/17/72. 2. USSR author's certificate NO 410326, cl. G 01R 23/00, 04.24.72. "