SU1370620A1 - Phase indicator - Google Patents

Description

(21) 4115123 / 24-21

(22) 04.06.86

(46) 01/30/88. Bul № 4

(71) Omsk television factory

(72) A.I.Ermakov

(53) 621.317.37 (088.8)

(56) USSR Copyright Certificate 949549, cl. G 01 R 29/18, 1980.

USSR Author's Certificate No. 1153304, cl. G 01 R 29/18, 1983.

(54) INDEX OF PHASES

(57) The invention relates to devices for measuring electrical quantities and can be used to determine the conditional number or letter designation of the phase of the electrical circuit being measured, as well as

to control the presence or absence of phase voltage during repairs in electrical distribution, - tel devices designed

for switching phase voltages in various combinations on the load. The purpose of the invention — improving the electrical safety of performance of work — is achieved by reducing the number of connected phases. Another goal — increased reliability — is achieved by simplifying the design. The device contains shapers 1-4 of rectangular pulses, 2I 5, 6 and 7 zlemeits, indication elements 8-1I, a limiting resistor 12, a three-phase sinusoidal voltage generator with adjustable phase. The device uses the principle of indicating the moment of coincidence of the phases of the circuit being measured and the electrical oscillations of the generator, forming an artificial three-phase circuit with a hard ratio of the phases of the oscillations generated. 2 Il.

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The invention relates to devices for measuring electrical quantities and can be used to determine the conditional number or letter designation of the phase of the measured electrical circuit and to monitor the presence or absence of phase voltage during repairs of electrical distribution devices intended for switching phase voltages in various combinations load.

The purpose of the invention is to increase the electrical safety of the work by reducing the number of connected phases and reliability by simplifying the design of the device.

FIG. 1 shows a diagram of the device; in fig. 2 - diagrams of signals at various points of the device. The device contains shapers 1-4 rectangular pulses of sinusoidal signals, elements 2 and 5-7, elements 8-11 of indication, a limiting resistor 12 and a generator 13 of a three-phase sinusoidal voltage with adjustable phase, while the input of the first driver 1 is connected to the second terminal of the device and its output - to the first inputs of elements 2 and 5-7, to the second inputs of which are connected respectively the outputs of the second 2, third 3 and fourth D drivers, the inputs of which are connected to the corresponding outputs of the generator 13 three-phase syn voltage, and the outputs of elements 2 and 5-7 are connected to elements 8-10 of the display.

The operation of the phase indicator is based on the principle of 1 indication of the moment when the phases of the electric oscillations of the circuit being measured and the electrical oscillations of the internal generator constitute an artificial three-phase circuit with a hard phase relationship of the generated oscillations. with a certain threshold from a signal of one polarity.

FIG. 2a shows the voltage plots of the measured circuit, where the line A-A shows 1Pz1 the possible values of the voltage thresholds for the triggering of Schmidt triggers, and the line BB the possible values of the voltages for setting

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laziness thresholds. operation of one-shot. The intersection points of these lines with the phase signal plots determine the magnitudes of these voltages. FIG. Figures 2b, c, and d represent rectangular pulses received from shapers. The dashed areas in FIG. 2d, e, l, conventionally indicate the range of the displacement of the generator pulses along the time axis due to the initial adjustment of the phases. FIG. Figure 2b shows the voltage plots of the internal generator.

The device works as follows.

Before starting the measurements, the input of the phase indicator device is connected to one of the phase conductors at the input of the switchgear, and the oscillator of the initial phase of the internal oscillator 13 adjusts the generator so that two display elements light up at the device output: and any of the three display elements 8-10, denoting the conditional phase number, for example, element 8. When the phase indicator input from this wire is disconnected, the display elements go out, and when Switching the input of the pointer to any other potential point of the electrical switchgear circuit again illuminates the display element 11 and the element highlighting the conditional phase number, the phase shift of which coincides with the phase of the signal of the artificial three-phase network. In the absence of phase voltage at this point, none of the display elements is illuminated.

Claims (1)

Invention Formula A phase indicator containing four pulse drivers, an indicating unit and three 2I elements, whose inputs are connected to the outputs of the formers, and the outputs to the input of the indicating unit, characterized in that in order to increase electrical safety by reducing the number of connected phases and decreasing the reliability by simplifying the circuit, a three-phase voltage generator with an adjustable initial phase is entered into it, the display unit consists of four display elements, three of connected to one of the poles of the power source, and the fourth display element through a resistor connected to the input terminal and the input of the first driver, the output of which is connected to the first inputs of the elements and A 6 f I g d t l 2I, to the second inputs of which, respectively, the first, second and third outputs of the three-phase generator with adjustable phase are connected via the second, third and fourth drivers. I I  t t t t Fie.2