SU1290430A2 - D.c.transducer - Google Patents

Abstract

The invention relates to the field of measurement technology and is an improvement of the invention in accordance with P 1 ed. No. 277065. The goal is to extend the functionality of the DC sensor. In order to achieve it, a single-turn magnetic amplifier 1 with a self-drive, a threshold element 2, a first output bus (VS), a quasi-selector 4, a control key 3, and a second HS were included in the DPT. The invention makes it possible to discern the polarity of the current to be converted and to convert the current amplitude to polar into a separate signal. positive and negative polarity. 3 il. (/ Yu

Description

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The invention relates to electrical measurements, can be used in instruments for measuring heterogeneous direct current and improving the known device by means of av. No. 277065.

The purpose of the invention is to expand the functional capabilities by selecting the output signals for converting a direct current of both positive and negative polarity.

FIG. 1 is a block diagram of a DC sensor; in fig. 2 timing charts, characterizing his work; FIG. 3 is an electrical schematic diagram of a possible implementation of a quasi selector.

The DC sensor contains a single-ended magnetic amplifier 1 with self-engagement, the input of which is connected to the input buses, and the output through the threshold element 2 to the first output bus. The output of magnetic amplifier 1 is also connected via a control key 3 to the second output bus. The control input of the control key 3 is connected to the output of the quasi-selector 4 ,. the input of which is connected to the first output bus.

The quasi-selector may contain, for example, the first 5 and second 6 elements of NAND, the first 7, the second 8, the third 9, the fourth 10 and the fifth 11 resisters, the first 12 and second 13 capacitors, the transistor 14, the HZ source of the reference voltage and comparator 16. At the same time, the input of the quasi-selector 4 is connected to the first input of the first element AND-NOT 5, the second input of which is connected through the first resistor 7 in series with the first capacitor 12 and connected to the output of the second AND-NE element 6. The connected terminals of the resistor 7 and the capacitor 12 is connected through the second resistor 8 to the common INE. The output of the first element IS-HE 5 is connected to both inputs of the second element AND-HE 6, as well as through thirds, the resistor 9 with the base of the transistor 14, the collector of which through the fourth resistor 10 is connected to the power bus and the emitter is connected to the common bus. The collector of the transistor 14 is also connected to the community via the second capacitor 13 and through the fifth resistor 11 to the first input of the comparator 16, between which the second input and the common bus

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the source of the reference voltage is 15. The output of the comparator 16 is connected to the output of the quasi-selector 4.

The DC sensor operates as follows.

To the input of the magnetic amplifier 1, apply ;: a convertible direct current, and to its input of the excitation - an alternating voltage, for example, a square wave. With one polarity of the current to be converted, for example, a positive one, the magnetic amplifier 1 operates on the right side of the characteristic with positive feedback in the saturation mode. The amplitude of the output pulses is unchanged and has the maximum value. The magnitude of the output pulses of the magnetic amplifier 1 is proportional to the value of the converted current. When the polarity of the converted current changes, the magnetic amplifier 1 operates on the left branch of the characteristic with negative feedback without saturation. Therefore, the amplitude of the output pulses is proportional to the magnitude of the converted current. The output pulses of the magnetic amplifier 1 are fed to the threshold element 2. The threshold level of the threshold element 2 is chosen greater than the maximum amplitude of the pulses during operation of the magnetic amplifier on the left characteristic branch and lower than the amplitude of the pulses during operation on the right branch (Fig. 2a).

When the magnetic amplifier 1 is operated on the right branch, its output pulses are fed through the threshold element 2 to the first output bus and to the input of the quasi-selector 4 (Fig. 2S). The input pulses of the quasi-selector 4. through the elements AND-HE 5 and 6 arrive at the base of the transistor 14 (Fig. 2B), which with the frequency of these pulses discharges the capacitor 13, charging- | c through a resistor 10 from the source connected to the bus nutrition The voltage on the capacitor 13 does not exceed the magnitude of the voltage of the source 15 of the reference voltage (Figure 2b). At the output of the comparator 16, a low level signal is generated (Fig. 2). Controlled key 3 at. This is locked. The magnitude of the current to be converted can be measured by measuring the pulse duration on the first output bus. When the polarity of the converted current changes, the amplitude of the output pulses of the magnetic amplifier 1

the threshold level and they do not pass through the threshold element 2. In the absence of pulses at the input of the quasi-selector 4, its transistor 14 is not turned on, and 5 the capacitor 13 is charged to a level exceeding the reference voltage of source 15 (Fig. 2 & 7 ). The comparator 16 generates a high-level signal at the output (Fig. 28), which unlocks key W 3. The output pulses of the magnetic amplifier 1 are fed through the key 3 to the second output bus (Fig. 2f). The magnitude of the current to be converted can be measured by measuring the amplitude of the pulse-15 ow on the second output bus.

Thus, the invention will make it possible to distinguish the polarity of the current being converted and the converter to the output signal separately the amplitude of the current 20

1290430

becomes less positive and negative polarity, which expands its functionality. DC sensor.

Claims (1)

Invention Formula DC sensor auth. St. No. 277065, characterized in that, in order to expand its functionality, a quasi-selector, a control key and a second output bus are additionally introduced into it, the control key of the power outputs connected between the output of the magnetic amplifier and the second output bus, and A control input is connected to the output of a quasi-selector, whose input is connected to the first output bus. but ( Invention Formula DC sensor auth. St. No. 277065, characterized in that, in order to expand its functionality, a quasi-selector, a control key and a second output bus are additionally introduced into it, the control key of the power outputs connected between the output of the magnetic amplifier and the second output bus, and A control input is connected to the output of a quasi-selector, whose input is connected to the first output bus.  Ufft, iX2 AT UBi, / X6  i ffMXf.  / Xs fae, Z J6 fff / jtop cfruff.3 Editor K. Voloshchuk Compiled by A. Puchkovsky Tehred L.Oleynik Proofreader L. Pilipenko Order 7910/52 Circulation 720 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