SU1290191A1 - Frequency meter - Google Patents

Abstract

This invention relates to electrical measuring technology. The purpose of the invention is to simplify the device. The frequency meter contains a driver 1 pulses, a counter 2 pulses, registers 3 and 4, a crystal oscillator 5, a divider 6 and a delay element 7. Block 8 is entered into the device. This provides a continuous counting of the input pulses and a cyclic count of the counting results at the output of the device. In this case, the error resulting from pulse counting at any measurement time does not exceed one pulse in the absence of accumulation of an error in the counting process. 1 il. (Lu x

Description

112

The invention relates to electrical measuring equipment and is intended to measure the average value of a signal frequency.

The purpose of the invention is to simplify the device and expand the range of measured frequencies. The drawing shows a block diagram of a frequency meter

The device contains a pulse generator 1/1, a pulse counter 2 connected in series, a first register 3, a second register 4, a series-connected crystal oscillator 5, a divider 6, a delay element 7, and also a subtraction unit 8. You move the delay element 7 and the output of the divider are connected respectively to the write enable input of the first and second registers 3,4, and the output of the driver 1 is connected to the input of the counter 2 pulses. The input of the subtracted subtraction unit 8 is connected to the output of the second register 4, the input of the subtractable is connected to the output of the first register 3, and the output of the subtraction unit 8 is the output of the device.

The frequency meter works as follows.

The input signal through the pulse shaper 1, which converts it into a sequence of unipolar pulses, is fed to the input of the pulse counter 2, counting continuously. Since in this device there is no need to install a counter 2 pulses. In O or some other state, it is possible to take into account information about all pulses arriving at its input.

At the time of entry of the recording pulse from the output of the delay element 7, the code received from the output of the pulse counter 2, corresponding to some number N (t + it), is recorded in the first register 3. After a certain time interval T after the arrival of the write pulse to the input of the delay element 7 specified by the crystal oscillator 5 and the frequency divider 6, the number code N (t + At) is overwritten from the first register 3 into the second register 4 and through time t determined by delay element 7 writing a new code of the number N (t + jt + T) from the output of the pulse counter 2 to the first register 3. The delay element 7 serves for time diversity

0

five

five

ABOUT

thirty

35

40

45

moments of writing code in the second register 4 and in the first register 3.

Thus, at the multi-bit input of the reduced subtraction unit 8 there will be a code of the number N (t + 4t + T), the value of which differs from the code of the number N (t + 4t) at the multi-bit input of the subtracted by the number of pulses arriving at the input of the counter 2 pulses in time T between successive recording pulses from the output of delay element 7.

The subtraction unit 8 can be implemented, for example, on the adder, the multi-digit input of the first term of which receives the code from the output of the first register 3 directly, and the multi-digit input of the second term contains the return code from the output of the second register 4, and to the transfer input of the adder served by 1.

The capacitance of the counter 2 pulses is selected by the maximum possible number of pulses of the input signal during the time T. The delay time of the delay element 7 is selected in accordance with the speed of the microcircuits on which the second register 4 is built.

The device provides continuous counting of input pulses and cyclical output of counting results to the output of the device, while the error resulting from counting pulses for any measurement time does not exceed one pulse and there is no accumulation of error in the counting process.

The device has an extended range of measured frequencies, since the pulses of the measured frequency arrive directly at the counter and there is no need to add a pulse between adjacent pulses of the measured frequency at the end of the zero pulse, as in the known.

The frequency meter can be used in automatic frequency control systems.

Claims (1)

Invention Formula A frequency meter containing a pulse shaper, a pulse meter connected in series, the first and second registers, as well as a series-connected crystal oscillator, a divider and a delay element31290191-4 kN, and the output of the delay element in which the input is readable and the output of the divider is connected to the corresponding output of the second register in regards to the recorder resolution input, the input of the decremented one - with the output of the first and second registers; shaper output With the purpose of 5 pulses connected to the input of the device simplifying and expanding diameters counter, and the output of the frequency range subtraction unit, the unit entered is the device output.