SU1191951A1 - Device for dividing voltage - Google Patents

Abstract

A DEVICE FOR DIVIDING A VOLTAGE, containing an inductive divider and control circuit, characterized in that, in order to save materials, reduce size and weight, and increase speed when changing the output voltage in small limits around a set value, it is equipped with a resistive divider, a digital-to-analog converter, phase inverter and adder, one input of which is connected to the input of a resistive divider, and the other - to the output of a phase inverter, resistive divider, digital-to-analog converter and phase The inverter is connected in series, the input of the inductive divider is connected to the output of the adder, the input of the resistive divider is connected to the input, and the output (L of the inductive divider - to the output of the device.

Description

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About the invention The invention relates to electrical measuring equipment and can, in particular, be used in the creation of code-controlled voltage dividers with improved weight and size indicators and increased speed. The aim of the invention is to save materials, reduce size and weight, and improve performance when changing the output voltage in small limits around a set value. FIG. 1 shows a block diagram of the proposed device; in fig. 2 is a schematic diagram of one of the variants of the proposed device. The device consists of a series-connected resistive voltage divider 1 with a fixed transfer coefficient KI, a digital-to-analog converter (DAC) 2 with a variable transmission coefficient Ka, a phase inverter 3 with a transmission coefficient ± Kj of the adder 4 with a transmission ratio K4, one of the inputs of which is connected to the input terminal device 5 and the input resistive voltage divider 1, and the other with the output of phase inverter 3, inductive divider 6, the input of which is connected to the output of the adder 4 and the control circuit 7, issuing sy control drives to blocks 2, 3, 6. The output of the device is the output of block 6 connected to the output terminal 8 (Fig. 1). The device works as follows. The input voltage UBX is applied to voltage divider 1, the output voltage of which Ui KjUBX is fed to the input of the DAC 2, whose speed is much higher than the speed of the inductive divider (PID). The voltage at the output of this block, equal to Ui KEUi K2 KiUsjt, varies from min (at K 0) to UzmAX (at Kg Kgtgos) - Phase Inverter 3 inverts or does not invert this voltage (i.e. U3 ± KjU2) and applies to one of the inputs of the adder 4. To the other input of the adder, connected to the clamp 5, the input voltage UBX is applied. The output voltage of the adder U (iv- | - of) K4 is applied to the input of the inductive divider 6, the transmission coefficient of which is equal to KS. The transmission ratios Kg, Kj, KS are set by the control circuit 7. The output voltage of the device, removed from the clamp 8, is determined as follows. and K4K5 (l ± KiK2K3) Uex, (1) where KI, Ks, Kd are constant values and Ki, Kg, Ks, K4 1. As follows from expression (1) with a constant value of the input voltage, the change ( dividing the output voltage level can be done by changing the transfer factor K5 of the inductive divider 6 — coarse adjustment, and changing the transfer coefficient Kg of the faster unit 2 — precise adjustment (changing the output voltage within small limits from the set value). One of the possible variants of the circuit diagram of the device proposed is shown in FIG. 2. Voltage divider 1 is the simplest resistive divider of resistors Ri and R. A DAC consists of a resistive matrix, electronic switches and an operational amplifier. A phase inverter consists of an operational amplifier and a dual electronic switch, depending on the position of which the circuit can operate as a repeater or signal inverter. The adder is made on the transformer whose primary winding Wi is turned on at the phase inverter output, and the secondary W - between the inputs of the device and the inductive divider. A significant advantage of the device proposed is that the use of a DAC allows the device to speed up by several orders of magnitude when the output voltage varies within small limits, around a set value. Let, for example, in the initial state, the transmission coefficient of the device was equal to Kp 0.100000. You need to install, 000010. In the proposed device, this increment is provided by changing the K 2 D / A transfer ratio by the appropriate amount. In this case, the transmission ratio of the IDN remains unchanged. In the known device, the increment of the transmission coefficient (output voltage) is ensured only by switching the transmission coefficient Kg to the IDN (in this case, switching its fifth decade). Since the speed of the known device (tvcT.20Mc) is significantly less than the speed of the microelectronic DAC (, ms). This means that the speed of the proposed device in the mode of small changes in the output voltage near the set value is significantly higher than the speed of the known device. In addition, the introduction of a voltage divider 1 DAC and a phase inverter 3 makes it possible to replace part of the lower decades of the inductive divider. For example, in a known device, in order to provide a transfer ratio of 0.000001, six ten-day autotransformers are required, made of P ferromagnetic cores of high quality permallo (two decades on one core). In the proposed device with the same resolution

abilities need four decade autotransformers on two cores. The role of the fifth and sixth decades is performed by blocks 1, 2, 3. Therefore, in the proposed device, the number of permalloy cores and the number of electromagnetic relays can be reduced by one third. Blocks 1,2, 3, are microelectronic, mass-produced by industrial intelligence, while decade autotransformers require a large amount of manual labor in their production.

Thus, the use of the proposed solution in building voltage dividers will allow, with a significant reduction in material and labor costs, reduce the size and weight of the device, increase the performance by more than 10 times when changing the output voltage within small limits around the set value; therefore, it is more efficient to apply voltage dividers in

automated calibration complexes during metrological works.

Claims (1)

DEVICE- FOR VOLTAGE DIVISION, containing an inductive divider and control circuit, characterized in that, in order to save materials, reduce dimensions and weight and increase speed when the output voltage changes within small limits around the set value, it is equipped with a resistive divider, digital-to-analog converter, phase inverter and an adder, one input of which is connected to the input of the resistive divider, and the other to the output of the phase inverter, resistive divider, digital-to-analog converter, and phase-inverter The torus is connected in series, the input of the inductive divider connected to the output of the adder, the input of the resistive divider connected to the input, and the output of the inductive divider connected to the output of the device.