SU702303A2 - Quadrature equilibrium detector - Google Patents

Description

(54) SQUARE DETECTOR OF EQUILIBRIUM

one

The invention relates to the field of electrical measuring equipment, can be used in bridges and compensators of alternating current and is. improvement of the known quadrature equilibrium detector.

The basic invention of the author's certificate No. 568896 describes a quadrature detector containing two matching devices, the output of one of which through an amplification. The arc is connected in parallel to the information input of the element, Banned and connected. From the inputs of the element I, the output of which is connected with one of the integrator inputs, the output of the second matching device is connected via a second amplifier-limiter in parallel to the second input of the And element and to the inhibiting input of the Ban element whose output is connected to the second progress Integrator -1.

The disadvantage of this device is the possibility of the occurrence of ambiguous information about the phase shift

between compared harmonic

signals, due to the lack of synchronization of the beginning of the comparison.

The purpose of the invention is to improve the accuracy of comparing two harmonic signals.

This is achieved by the fact that the equilibrium quadrature detector, which contains two matching devices, two amplifier-limiter, elements I, Zepret and an integrator, with the output of one of the matching devices connected through the amplifier-limiter to the information input of the Forbid element and one of the inputs of the element And the output of the second matching device through the second amplifier-limiter is connected to the inverse input of the element Ban and to the second input of the element And, the outputs of the elements And And the Ban are connected respectively to the first and the second input of the integrator,

0 the control unit is entered,., The input of the port is connected to the output of one of the limiting amplifiers, and the output of the control unit is connected in parallel to the second information input of the element 5 and the ban to the third input of the element I.

The control unit contains the element NOT, two pulse drivers, the elements Forbid, AND, and the RS flip-flop, and

0 the input of the control unit is connected in parallel with the input of one of the pulse shapers and through the element NOT to the input of the second impulse generator, the output of which is connected in parallel to the inhibitory input of the Ban element and to one of the inputs of the element I, the second input of which is connected in parallel to the output of the first pulse generator and informational input of the Inhibit element, the outputs of the AND elements and the Inhibit element are connected to the first and second inputs of the RS flip-flop, the output of which is connected to the output of the control block. Such a constructive solution ensures unambiguous information on the phase shift between two compared harmonic signals. FIG. 1 shows a block diagram of the detector described in FIG. 2 - block diagram of the control unit. The quadrature equilibrium detector contains matching devices 1 and 2, limiting amplifiers 3 and 4, a control unit 5, an element Prohibiting element 6 and element 7 and an integrator 8. The output of the integrator is the output of the device. The control unit contains the HE element 9, the pulse formers 10 and 11, the Inhibit element 12, the AND element 13 and the 3R-three17 14 output of the RS-flip-flop is the output of the control unit. Harmonic signals UJ and by which it is necessary to establish a phase shift equal to ± it / 2, are fed through matching devices 1 and 2 to the inputs of the limiting amplifiers 3 and 4. The pulses corresponding to, for example, the positive half-wave sinusoids of the input signals U and U. the outputs of the limiting amplifiers 3 and 4 are fed in parallel to the inputs of the Inhibit b and I 7 elements, and the pulses from the amplifier-limiting 3 are also fed to the input of the control unit 5, i.e. at the same time, the input element HE 9 and the input of the pulse former 10, from the output of which a narrow pulse formed at the moment of the input signal transition from a low level to a high one goes simultaneously to the information input of the element Ban 12 and to one of the inputs of the element 13. From the output of the HB 9 element, the inverted signal is fed to the input of the pulse former 11, from the output of which a narrow pulse formed at the moment of the input signal transition from a high level to a low degree is given simultaneously to the inhibiting input of the element ret 12, second item WMOs ban 12 and a second input of AND gate 13.

Claims (1)

four . From the output of the Inhibit 12 element, the signal is fed to one of the inputs of the RS flip-flop 14, for example, the first, and from the output of the And 13 element, the signal is fed to the second input of the specified trigger. . In case the measurement starts during the positive half-wave of the U signal, the pulse from the output of the Ban 12 element sets the RS flip-flop 14 to the zero state, i.e. the output of the control unit is given a low level signal, and the first pulse from the output of the element And 13, which coincides with the beginning of the positive half-wave of the signal and sets the RS flip-flop 14 to one state. If the measurement starts from the negative half-wave of the signal, and setting the RS-flip-flop 14 to the zero state is not performed, since the pulse from the Ban 12 element is absent. In this case, the RS flip-flop 14 can find, with in any of the stable states, for example, single. When the RS-flip-flop 14 is in the zero state, the first pulse from the element And 13 sets the RS-flip-flop to the one state. the formation at their outputs of signals whose duration depends only on the magnitude of the phase shift between the compared harmonic signals and and and and does not depend on the moment of measurement, these signals are parallelized, each of them separately, at the integrator input 8, sex The pharity of the signal at the input of which gives unambiguous information about the phase shift between the compared harmonic signals. The use of the invention will allow one to avoid obtaining erroneous information on the establishment of a quadrature between the compared harmonic signals. Claim 1, The quadrature equilibrium detector according to the author's certificate No. 568896, characterized in that, in order to improve the accuracy of comparing the two.; control signals, the input of which is connected to the output of one of the limiting amplifiers connected to the information input of the Ban element, and the output of the control unit connected in parallel to the second information input of the Ban element and to the input of the I. 2, The quadrature equilibrium detector of nt 1, characterized in that the control unit contains the element NOT, two pulse drivers, the elements of the Inhibit, AND, and RS-trigger with the input of the control unit connected in parallel with the input of one of the pulse conditioners and through the element NOT with the input the second pulse former, the output of which is connected in parallel to the prohibitor input of the Prohibit element and to one of The inputs of the And element, the second input of which is connected in parallel to the output of the first pulse generator and the information input of the Ban element, the outputs of the And and Ban elements are connected to the first and second inputs of the RS flip-flop, the output of which is connected to the output of the control unit. Sources of information taken into account in the examination 1, copyright certificate 0 568896, cl. G 01 R 17/00, 11.06.75. Led ten / 2