SU1337811A1 - Phase difference-to-voltage converter - Google Patents

Abstract

This invention relates to the field of radio metering technology. In combination with a voltmeter, the proposed converter can be used as a phase meter, and in combination with a recorder, an analog-digital converter, in systems of automatic information processing. The device contains amplifiers-limiters 1 and 2, shapers 3, 4 and 6 pulses, integrator 5, triggers 7 and 8, relaxer 9, converter 10, duty cycle - voltage. The use of an electron-commutated two-channel driver for controlling triggers made it possible to drastically increase the speed of the device as compared with lime. In addition, the device raises the upper frequency of the conversion without using frequency conversion and lowers the minimum input signal level to 100 µV by increasing the noise immunity of the system and introducing an additional phase shift. An upper operating frequency of about 60 MHz was obtained without heterodyning. 3 il. i (L 00 with 00

Description

The invention relates to a radio measuring technique and can be used in combination with a voltmeter as a phase meter, and in combination with a recorder, an analog-to-digital converter in automatic information processing systems.

The purpose of the invention is to improve the accuracy of converting small phase differences with noisy input signals and to provide a follow mode for converting phase difference into voltage.

Fig, 1 shows a functional diagram of the proposed Converter; FIGS. 2 and 3 are voltage diagrams explaining its operation.

The phase difference to voltage converter contains amplifiers-limiters 1 and 2, shapers 3 and 4 pulses, integrator 5, shaper 6 pulses, triggers 7 and 8, relaxer 9, and converter 10 duty cycle - voltage.

The converter inputs are the inputs of the limiting amplifiers 1 and 2, the outputs of 3, 4, and 6 pulses connected to the inputs of the first, second, and third drivers, respectively. The pulse shaper 6 is outputted through a series-connected integrator 5 and relaxer 9 connected to the second input. The first shaper 3 pulses and the third input of the inverter 10 are the duty cycle - voltage. The first driver 3 pulses the first output is connected to the first input of the trigger 7, and the second output to the first input of the trigger 8. The second driver 4 of the pulses the first output is connected to the second input of the trigger 7, and the second output to the second input of the trigger 8. The outputs of the triggers 7 and 8 are connected respectively to the first and second inputs of the converter 10, the duty ratio - voltage, the output of which is the output of the phase difference to voltage converter.

The phase difference to voltage converter operates as follows.

The input signals U, and U (Figs 2c1, 5) are amplified) and limited by amplifiers-limiters 1 and 2. The output voltage of the amplifier-limiter 1 (Fig.2b), the fronts of which correspond to zero crossing of the input signal U, (FIG. 2a) is fed to the input of the impulse generator 3 pulses, the output pulses of which (FIGS. 2a, e) correspond to the fronts of the output voltage of the amplifier-limiter. When measuring the phase differences remote from O and 360, the pulses shown in Fig. 2a are sent to bus a, and the pulses shown in Fig. 2e to the bus &. The output voltage of the amplifier - limiter 2 (Fig.2-g) is fed to the input of the driver 4 pulses. The output pulses of this driver (Fig. 2g, O correspond to zero crossing of the signal Uj (Fig. 25). The pulses shown in Fig. 2g go to the bus%, the pulses shown in Fig. 2g to the bus z. Triggers 7 and 8, to which impulses are sent along buses o and 5 i, respectively, generate impulses whose duration is equal to the time interval between zero-crossing in one direction of signals and Uj, duration ut ,, and At t4-tj (FIG. 2c, to ). The output signals from the flip-flops go to the inputs of the converter 10 duty cycle - the voltage that the The voltage is proportional to (ut, + ut,) / 2Т, i.e., inversely proportional to the average duty cycle of the pulse sequences from the outputs of the trigger (T is the period of the signals and, and U2).

From the outputs of limiting amplifiers 1 and 2, signals (Fig. 28, d) are also fed to the inputs of the pulse shaper 6, which implements the NO-I operation (a possible variant of this operation: one of the signals shown in Fig. 2, D is inverted and, together with another signal, is fed to the AND circuit. At the output of the pulse generator 6, a sequence of pulses is produced, the duration of which is equal to the time interval during which the positive voltage of the signal U coincides with the negative 1m voltage U or the positive voltage U coincides with the negative voltage U (, Pulse sequences from the output the driver 6 pulses (the pulse duration in these sequences is equal to ut, or u t) is fed to the input of the integrator 5. Amplifiers-limiters 1 and 2, the driver of 6 pulses and the integrator 5 surround Cozy phasometric transducer phase difference voltage that implements the principle of operation of phase meters with overlap. The dependence of the output voltage of the integrator on the phase difference between U and lU is shown in Fig. Over. The relaxer 9 operates at levels and, its input is connected to the output integrator The output voltage of the relaxer, the dependence of which on the phase difference between and, and, and is shown in Fig. 35, is fed to the control input of the switched shaper of 3 pulses and the converter 10 is the duty cycle - voltage. At voltages at the input of the relaxer, smaller than u, a high logical level of voltage is established at its output, and at voltages greater than and, the relaxer returns to a state with a low logical level of output voltage. If the signals are noisy, then the breaks in FIG. For the integrator's output voltage does not depend on the phase difference between U, and U is shown in section). These are overlapping converter dead zones. Since the relaxer switches voltage away from the dead zones, the existence of the latter does not affect the operation of the device.

When the phase difference between U and U is close to O and 360 ° (the interval f is from

FIG. 3) The release voltage of the relaxer 9 controls the pulse shaper 3 so that the pulse sequence shown in FIG. 2 (goes to bus S and the pulse sequence shown in FIG. 2e) to bus A. This may be implemented, for example, by cross-switching of zero-pulse-generated pulses using a two-position switch (as in the prototype) or by forming pulses at a high logic level of the voltage at the relaxator output from the voltage that is antiphase in FIG. 26.

In this case, the outputs of the triggers 7 and 8 of the pulse duration are equal to t - t | and t - tj. During the action at the control input of the generator of 3 high-level pulses of the output voltage of the relaxator, pulses from the triggers receive increments in duration corresponding to the shaded areas in Fig. 2i, k. The sum of these sites by duration

5 0 5 0

five

0 5

0

equal to the signal period. Since the output voltage of the converter is a duty cycle — the voltage is proportional to the ratio of the half-sum of the pulse durations at the output of the flip-flops to the signal period, when the logic level of the output voltage of the relaxer is high, the phase shift is 180 (as in the prototype).

The output voltage from the relaxer also goes to the third input of the converter 10, the duty cycle — the voltage is summed in such a way that the high voltage level of this voltage is changed by the output voltage of the converter 10 by an amount corresponding to 180, i.e. an additional phase shift 180 is compensated (the DC voltage from the relaxator output can be considered as a sequence of pulses with a duty cycle equal to one), as a result, the next conversion mode is the phase difference - voltage.

The use of information received in parallel to the conversion channel to introduce additional phase shift 180 is the phase difference — the voltage performed according to the principle used in phase meters, and the use of an electronically commutable two-channel trigger control pulse generator improves the performance of the proposed device compared to the prototype.

In addition, the invention makes it possible to increase the upper operating frequency of the converter without using frequency conversion and to reduce the minimum level of input signals by increasing the noise immunity of the system for introducing an additional phase shift. In the proposed converter, an upper operating frequency of 60 MHz without the use of hetero-diffusion is obtained, a continuous conversion mode is provided with a uniform change in the phase difference from 0 to 360 over a time of about 10 s more and the operability is maintained at a decrease in the input signal level to 100 µV.

Claims (1)

Invention Formula The phase difference to voltage converter, the contents of the two amplifiers of the limiter, whose inputs are the converter inputs, and the outputs are connected to the corresponding inputs of the first and second pulse formers, the first pulse driver with the first output is connected to the first input of the first trigger, and the second output to the first input of the second trigger, the second pulse shaper of the first output is connected to the second input of the first trigger, and the second output to the second input of the second trigger, integrator, output connected to input relaxator, and the output of the latter is connected to the second Well the input of the first driver, different TL M, that, in order to improve noise immunity and speed, a third pulse shaper and a transducer are introduced, the duty cycle is voltage, the inputs of the third pulse shaper are connected to the outputs of the limiting amplifiers, and the output is connected to the integrator input, the first and the second inputs of the inverter - the voltage is connected to the outputs of the respective triggers, the third input to the output of the relaxer, and the output is the output of the converter. but and and It about Editor A.Lezhnina Compiled by S. Kulish Tehred I.Popovich Proofreader E.roshko Order 4126 / i3 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Fi8.3