SU1257563A1 - Device for measuring phase shift - Google Patents

Abstract

The invention can be used in automated information measuring systems for measuring the phase shift of low frequency electrical oscillations. The purpose of the invention is to simplify the device. The device contains drivers 1 and Z ,. Trigger 3, generator 12, divider 13 x-speeds and counters 14, 15 and 16. The introduction of an inverter 4, single vibrators 5 and 6, elements I 7-10 and element STINE 11 with the formation of new connections between the elements of the device allows variable fill the counter frequency and reduce the time to get the result. In this case, computational operations, such as multiplying or dividing codes of numbers, are excluded from the procedure for obtaining a result, which makes it possible to improve the measurement accuracy. 1 il. () Yu O1 SP 05 SB

Description

The invention relates to digital measurement technology and can be used in automated information-measuring systems for measuring the phase shift of low-frequency electrical oscillations.

The purpose of the invention is to simplify the device by varying the frequency of filling the counters and reducing the time to get the result.

The drawing shows a functional diagram of the device.

The device contains drivers 1 and 2, trigger 3, inverter 4, single vibration devices 5 and 6, elements AND 7-10, element OR-HE 11, generator 12, frequency divider 13, counters 14-16. The input of the reference signal through the driver 1 is connected to the input 20 of the passage of pulses to the counter 14. With the trigger 3 and the first inputs of the ele, - At the same time, the same signal one by one

And 10 and OR-NOT 11. The second input of the AND 10 element is connected to the direct output of the trigger 3, and its third input is connected to the output of the frequency divider 13,

the input of which is connected to the generator 12. The synchronization input of the device is connected to the D-input of the trigger 3, the inverse output of which is connected to the synchronization output of the device and the second input of the OR-NOT 11 element, the output of which is in turn connected to the first inputs of the And 7-9 elements. The input of the measured signal is connected through the second shaper 2 connected in series, the one-shot 5 and the second input of the element And 8 are connected to the inputs R of the flip-flop 3 and the counter 14, as well as to the input Record counter 15..Furthermore, the output of the shaper 2 through the series-connected inverter 4, the second input element And 9, the one-shot 6 is connected to the input V of the counter 16 In addition, the output of the generator -12

through the second input of the element And 7 connect- 45 jca at its output, which,

is not connected with the counting input of the counter 15, the output of which is connected to its own input V and the counting input of the counter 16. The output of the And 10 element is connected to the subtractive input of the counter 14, the input of the R-counter 16, while the information HFjie is connected to the informational counter inputs 15.

The phase shift measurement is carried out as follows.

When a synchronizing level device arrives at the sync input at the first zero crossing

257563 2

of the reference signal From bottom to top, converted by the first driver 1 to unipolar pulses of long-term in the half-period of oscillation, the trigger 3 5 is set to 1 by the dynamic input, forming at the input of the element And 10 the level

1H h T1

., which, together with the level 1 present at its other input, from the first generator 10, permits the passage of pulses from the frequency divider 13 to the input of the counter 14, sets it to the state N C - C - the volume of the counter. The first impulse causes the counter to be reset to zero 16. At the end of the half-period of the reference signal, the output of the first driver 1 turns out to be a logic level O prohibited by the first input of the AND 10 element

the input together with the zero level from the inverted input of the trigger 3 via the other input of the WL-1 1 1 element sets on its input a logic level 1, which, entering the input of the I 7 element, permits the passage of pulses from the generator 12 quantizing pulses to the counter 15. Obviously that at equal frequency of quantization of time intervals, proportional, respectively, half-period and phase shift of signals, the number of quantum-impulses would be m and%. But, as the quantization frequency of the last of the indicated intervals is 180 times higher (when measured in degrees) or ii times (when measured in radians), then for an interval proportional to the phase shift, the number of pulses is calculated, respectively, 180 N or Nf pulses. The first of this series of pulses overflows | Counter 15, causing the appearance of a pulse

to its input of parallel recording resolution, in its turn, causes the transfer of the code of the number N from the counter 14 to the counter 15. Since this pulse, which also enters the counting input of the counter 16, is superfluous, its exclusion is performed with the corresponding connection of bits . The volume of the counter 15 is also equal to C, where C is a constant number, therefore when Ng enters it. impulses it overflows and the corresponding impulse again causes a write to

its number N and the summation of the unit in the counter 16. Thus, the counter 15 performs the function of a divider with a given division factor of N. When going through zero in any direction of the measured signal, the one-vibrator 5 forms a short pulse, which passed through the AND 8 element (since logical 1 is present at its other input), triggers 3 to zero state, zeroing counter 14 and sets counter C to state C, preparing it for the next measurement cycle. Moreover, the specified pulse, if it is formed in the first half-period of the reference signal, does not pass through the AND 8 element, since at its other input at this time there is a logical O from the output of the OR-NOT 11 element, defined by the level of the logical 1 s of the driver 1.

If the measurement is performed in degrees, then, taking into account the division factor of the frequency divider 13, equal to 180, in the summing counter 16 the result is obtained

p, 1§ONC N „.51

where N is the number of quantizing pulses that would be calculated for a time interval proportional to the phase shift with equal quantizing frequencies ,.

numerically equal to the phase shift in degrees.

If the measurement is in radians, then

rNc

 N.

with

 0.5 G

That is, the result is obtained in radians.

If the phase shift exceeds 180 or iT, then at the start of the counting of the quantizing pulses, in the time interval proportional to the phase shift, the code of the number 180 is recorded in the counter 16 for measurement in degrees or the number Tr for measurement in radians. The recording is carried out by applying a short pulse to the input of the resolution of parallel recording of the indicated counter 16 of the result generated by the single vibration 6 when the output at the output of the AND 9 element is a logic level 1 determined by the logic levels.

5 o 5 0

five

0

1 at its inputs, respectively, from the output of the inverter 4 and the element ILN-PE 11.

In digital measurement of the phase shift by the proposed device as compared with the prototype, such computational operations as multiplication or division of number codes are eliminated, which makes it possible to significantly increase the measurement accuracy.

Claims (1)

Invention Formula A device for measuring the phase shift, containing two shapers, whose inputs are the device's inputs, and the output of the first shaper is connected to the C input of a trigger, two counters, one of which is connected to the information outputs of the controlled frequency divider, a reference oscillator that differs In order to increase the accuracy, two single-oscillators, four AND elements, an OR-NOT element, a frequency divider, an inverter, are introduced into it, and the output of the second driver is connected to the first input of the first element through the single vibrator a And, the output of which is connected to the inputs Reset trigger, the first counter and the input of the controlled frequency divider, the output of the second driver is connected via an inverter to the first input of the second element And whose output through the second one-vibrator is connected to the input of the second counter counting, summing the 1st counting the input of which is connected to the output and the input of the resolution of the controlled frequency divider, the output of the reference oscillator through the frequency divider is connected to the first input of the third And element whose output is connected to the melting input of the first counter and the input Reset the second counter, the output of the reference generator is also connected to the first input of the fourth element AND, the output of which is connected to the counting input of the controlled frequency divider, the inverse output of the trigger is connected to the first input of the element OR NOT and is the synchronizing output of the device , the output of the first driver is connected to the second inputs of the OR-NOT element and the third element AND, the third input of which is connected to the direct output of the trigger, the output of the SHTM-NO element 51257563 6 The second inputs of the first counter are connected to the second outputs of the second counter, and the fourth elements of And,, are the output of the device, while the synchronizing input of the device is controlled by the divisor: the frequency of the device is connected to the D-code of the trigger, and the information - in the form of a counter.