SU1215076A1 - Method of testing voltage divider - Google Patents

Abstract

This invention relates to electrical measuring technology. The purpose of the invention is to improve the accuracy of verification. The source voltage 1 is constant and proportional to the division ratio of the calibrated divider 3, eg, Zhzheni. The voltage of the source 4 is formed increasing in time according to a certain law. Digital block 11 counts the pulses from the generator 10. At the moment of equal voltage from the output of source 4 and 0.5 E from the output of divider 3, the signal from the zero-body 5 stops counting pulses from the output of generator 10. Block 2 switches shoulders of divider 3 and counting pulses repeats. Digital block 11 determines the average number of pulses per cycle. The operation is similar when connecting a rotatable divider 2. The counting of pulses is done, until the increasing voltage reaches the level corresponding to the previously recorded number of pulses. block II. The readout unit 13 registers a number indicating the calibration error. 2 cl.

Description

The invention relates to electrical measuring equipment and is intended for use in the control and measuring equipment of direct current.

The purpose of the invention is to increase the accuracy of verification by eliminating its dependence on the stability of the supply voltage of a calibrated voltage divider.

Figure 1 shows the functional diagram of the device for the practical implementation of the method; Fig. 2 is a graphical illustration of the implementation of the proposed method for calibrating a voltage divider in a voltage-time coordinate system.

In Figure 2, the following is indicated: voltage E of the power of the rotatable divider, ("the generated rising voltage (for example, linearly) T is the time from the beginning of the formation of the voltage U to the time it reaches 0.5 E, K is the nominal the division factor, Kp is the real division factor, ui is the time interval between the moment of equality of voltage (im and constant voltage E K, proportional to K, and the moment when the voltage Um reaches the level Е -KH corresponding to the nominal division factor.

The device contains a source 1 (Fig.) Of a constant voltage, a voltage divider 2, an auxiliary voltage divider 3, a voltage source 4, a zero-body 5, two-position switches 6-9, a frequency generator 10, digital unit 11, control unit 12 and reading unit 13.

With the beginning of the formation of the rising voltage Om (Fig. 1), the measurement of time T, corresponding to a value of 0.5 E, is started. Then, the time, changes in voltage Ua, from zero to E Kj, is determined analytically from the ratio in ZTK.

at the moment of equality of the voltages U m and E Kf, the measurement of time begins again, ending at the moment when the voltage U a, the level EKc, is reached. For the time interval it is valid the i 2 TLK diffusion, where & K is the accuracy of the calibrated voltage divider.

The operation of the device shown in figure 2, is as follows.

The control unit 12 sets the dip switches 6.7 to arbitrary positions, connecting the shoulders of the auxiliary divider 3 to the poles of the source 1 constant

tension At the same time using two-way switches 9.8, block 12 connects the output of the auxiliary divider 3 to one of the inputs of the zero-body 5, and the source output

4 rising voltage - to another of his entrance. The source 4 is started and with the help of the digital unit 11 the counting of pulses from the output of the frequency generator 10 begins. At the moment of equality of the voltages Oo, from the output of the source 4 and 0.5 E from the output of the auxiliary divider 3 using a signal from the null organ. 5, the pulse generator count 10 is terminated.

The control unit 12 switches the shoulders of the auxiliary divider 3 using / by the switches 6.7 to the reverse position and the indicated cycle of counting the pulses of the generator 10 is repeated. At the end of the second cycle, the control unit 12 commands the digital unit 11 to determine the average number of pulses received from the generator output 10 for both cycles, generates a number corresponding to the nominal value K of the division factor of the rotatable divider 2 and switches the position of the two-position switches 8, 9 on the opposite. Thereby to one entrance

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the zero-organ 3 is connected to the output of source 4, and to another input is the output of a rotatable divider 2. Source 4 is restarted. At the time of the voltage ЕКв from the output of the rotatable divider 2 and tlm from the output of the source 4, the zero-body 5 triggers and the control unit 12 issues a command to count the pulses of the generator 10 until it reaches the increasing

voltage U level, corresponding to the number of pulses, previously recorded in the digital unit 1C i.e. the level characterizing the nominal value of the coefficient

the division of the calibrated divider 2. In the readout block 13 a number is recorded that reflects the error of the verification.

3 12

Claims (1)

Formula invented The rtosepKH voltage divider method, based on a comparison of two voltages, the first of which is formed by a constant and proportional division factor of the voltage divider being tested. This is characterized by the fact that, in order to increase the accuracy, the second voltage is formed increasing in time according to a given law , with the initial section of its volt-seconds characteristics determine the time of change of the rising voltage from zero to the level corresponding to the nominal coefficient 5 divisions, measure the time interval between the moment of equality of the two compared stresses and the moment when the rising voltage reaches the level, and the failure rate The 10 verified voltage divider is proportional to the measured time interval. Mill BUT FIG 2 Compiled by L.Morozov Editor O. Kolesnikova Tehred; A. Babinets Corrector E. Sirokhman 905/55 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Branch of PSh Patent, Uzhgorod, Proektna St., 4