SU1282016A1 - Device for measuring rate of change of frequency - Google Patents

Abstract

This invention relates to a measurement technique. Designed to monitor and measure the rate of change of frequency. The purpose of the invention — an increase in the accuracy of measuring the rate of change of frequency — is achieved by measuring the frequency of a signal in a two channel manner. The device contains an input driver 1-, counting channels 2, a driver 3 counting time, an indicator 5. To achieve the goal, a block 4 has been entered, a code census one-digit 12, a pause counter 13, a one-time 14 one-pulse and, accordingly, new functional connections. Shaper 3 contains the generator 9 reference frequency, the divider 10 frequency shaper 11 gates. Unit 4 contains a character extraction unit 15, an adder 16 and a code converter 17. The operation of the device consists in estimating the input frequency increment by parallel counting channels 2 of frequency measurement and by subtraction unit 4 for the normalized time produced by the shaper 3 of the counting time from the frequency of the generator 9. The device allows determining the rate of change of frequency in normalized units Hz / S, Hz / ms , 2 Il. (L

Description

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The invention relates to a measurement technique and is intended to monitor and measure the rate of change of frequency.

The purpose of the invention is to increase the accuracy of the measurement of the rate of change of frequency due to a two-channel measurement of the signal frequency,

Figure 1 shows the block diagram of the device; figure 2 - timing charts of the device.

A device for measuring the rate of change of frequency contains an input driver 1, counting channels 2, a driver 3 counting time, a block, 4 subtractors, an indicator 5.

The counting channel contains serially connected selector 6, counter 7, buffer register 8.

Shaper 3 counting time contains a series-connected reference frequency generator 9, frequency divider 10, shaper generator 11

The device also contains a census single-word 12, a pause counter 13, and a reset pulse one-shot 14.

Subtraction unit 4 contains a character extraction unit 15, a adder 16, a code converter 17.

In the device, the output of the input generator 1 is connected to the information inputs of the selectors 6, the selection inputs of which are connected to the first and second outputs of the generator 3 counting times, the outputs of the selectors 6 are connected to the inputs of counters 7 of counting channels 2, the outputs of the counters are connected via buffer registers 8 with inputs of side-by-side 4 subtraction, the output of which is connected to indicator 5g

The device is connected in series with the one-shot census 12 counter pause 13 and one-shot 14 reset pulse, the one-shot 12 census input to the ode is connected to the second output of the counting time generator 3, the clock input of the pause counter is connected to the second processing time divider 10, the counting time 3, single output code census 12 is connected to the control inputs of the buffer registers 8, and the output of the one-shot 14 of the reset pulse is connected to the control input of the counting time generator and to the counter-zeroing inputs 13 pauses and counters 7.

62

The operation of the device consists in estimating the input frequency increment by parallel counting frequency measurement channels 2 and subtraction unit 4 for the normalized time produced by the shaper 3 of the counting time from the frequency of the generator 9.

Strobe pulses of the same length, coming to the control inputs of the selectors 6 of the parallel counting frequency measurement channels directly next to each other (Fig. 2), create temporary gates for the counters 7, which are filled with the pulses generated from the input frequency by the input driver 1. Counters determine the number of pulses of the input signal during the counting

t.

MF

N

MF

f -N. t..a

where N., - the number of pulses of the input signal transmitted through the selector 6 of the first channel; N, is the number of pulses of the input signal that have passed through the selector 6 of the second channel; f K.f - frequency determined by the counters.

The result of frequency measurement in the form of a binary code enters the buffer registers 8 of the frequency code. With the end of the time count of the second channel

S.Ch.

one-shot 12 census code

produces a pulse, which opens the pause counter 13 and gives the command to simultaneously read the frequency codes from the buffer register 8 to the adder 16. Since the counting time in the channels is the same, but t ,, enters the 2nd channel immediately after the end of the counting time t 1st channel, the frequency difference in the channels is the increment of the input signal frequency f. For a normalized time.

Sum.or 16 determines this frequency increment.

The rate of change of frequency is expressed as frequency increment during the time of change, i.e.

,,

The counting time shaper generates a decade time of 1 ms, 10 ms, 100 MCj 1 s, 10 s, therefore the frequency increment determined by the total 31128201

rum is the rate of change of frequency, expressed in normalized units,

- Subtraction unit 4 determines this speed, taking into account the sign that .j is made by the character extracting unit 15. Information on the rate of change of frequency in the form of a direct or inverse code, depending on the sign from the umma, is converted in the converter 17 10 from a binary form into a readable form in the indicator 5 decimal form. Due to the presence of the memory in the indicator, the result of the previous measurement is stored (FIG. 2) at the time of the 5th measurement cycle. The cycle time depends on the duration of the pause, formed by the counter 13 pause. The capacity of the pause counter determines the length of the pause and is proportional to the period of the frequency. When the pause counter overflows, the next clock pulse closes the counter, while the one-shot 14 of the reset pulse produces a reset pulse that goes to the inputs of the O set of counters 7 and the gate driver 1 1 opens the next measurement cycle.

The measurement accuracy is determined by 30. The accuracy of the calculation time, which is formed from the frequency of the generator 9 and normalized by a decadal divider, i.e. is determined by the stability of the generator 9. Moreover, to improve the measurement accuracy at low input frequencies, a large

counting time t. In addition, the proposed 5 device allows to determine the rate of change of frequency in normalized units Hz / S, Hz / ms,

Claims (1)

Invention Formula A device for measuring the rate of change of frequency, containing an input driver, the output of which is connected to the inputs of two counting channels, a counting time driver, the first and second outputs of which are connected to the selection inputs of the counting channels, an indicator, characterized in that, in order to increase the measurement accuracy, A subtraction unit is introduced in the output, the output of which is connected to the input of the indicator and the codec census single-vibrator connected in series, the pause counter and the one-pulse reset pulse, the input of the single-input transducer the code entry is connected to the second output of the counting time generator, the clock input of the pause counter is connected to the clock output of the counting time generator, the output of the code rewriter single-oscillator is connected to the control inputs of the buffer registers, and the output of the reset pulse single-pulse generator with the terminating inputs of the pause counter and counting channels, the outputs of which are connected to the information inputs of the subtractor. MB to k k k k k k k k to k .