SU1241213A1 - Bipolar reference voltage source - Google Patents

Abstract

This invention relates to stabilized DC power supplies. The aim of the invention is to increase the stability and simplification of a dipole source of reference voltages. The source consists of control transistors 3, 4, which are opened by the current flowing through resistors 9, 10 when power is turned on to capacitors 1 and 2. A voltage appears at the source output, resulting in voltage on the outputs 48, 50 (49, 51) of the parametric stabilizer 7 (8) at the output of the voltage divider formed by resistors 21, 22 (23, 24). The signal from the stabilizer 7 (8) through the error amplifier 5 (6) is fed to the control electrode of the transistor 3 (4), adjusting the output voltage level. 1 il. (L go with S ("/; 47

Description

. eleven

The invention relates to electrical engineering and is intended to be used as a source of reference voltage in measuring equipment, in particular, in precision digital voltmeters.

The purpose of the invention is to increase stability and simplify a bipolar source of reference voltages.

The drawing shows a diagram of a bipolar source of voltage

The source contains rectifiers 1 and 2, regulating elements 3 and 4, amplifiers 5 and 6 mismatch J, parametric stabilizers 7 and 8, resistors, 9-28, capacitors 29-38, diodes 39 and 40, zener diodes 41 and 42, and output clamps 43-47.

First exit 1

with output terminal 44 (+ U ...,.).

Dlrtil

The second output of the sensor 1 through the regulating element 3 is connected to the output terminal 45 (common bus) and through the resistor 9 to the control input

regulatory element

t

The first output of the rectifier 2 through the regulating element 4 is connected to the output terminal 45 and through, a resistor 10 to the control input of the regulating element 4; The second output of the rectifier 2 is connected to the output terminal.

6 (

Amplifier 5- (6) mismatch

its output through a parallel connected resistor 11 (12) and. diode 39 (40) is connected to the control input of the regulating element 3 (4). The first output 48 (49) of the parametric stabilizer 7 (8) through the resistor 25 (26)

connected to the inverting input of the amplifier 5 (6) of the mismatch, which through the capacitor 33 (34) is connected to its output.

The non-inverting amplifier input 5 (6) of the error is connected to the output of the voltage divider formed by resistors 21 and 22 (23 and 24), the second terminals of which (input of the voltage divider) are connected to the common bus 45 and to the output terminal 44 (46). Capacitor 31 (32) is connected between the non-inverting input of the error amplifier 5 (6) and the common bus. The second output 50 (51) of the parametric stabilizer 7 (8) is connected to the output terminal 43 (47) and serves as the second output + Ufc ,, (- Ug ,,, P.

132.

The power supply circuits of the amplifiers 5 and 6 of the error are combined and connected to the output terminals 44 and 46 through RC filters formed by resistors 27 and 28 and capacitors 35 and 36. Between the output terminals 44 and 45 (46 and 45), the capacitor 37 (38) is turned on.

Rectifiers 1 and 2 can be made according to the full-wave scheme; A mittel with a smoothing filter at the output in one of the standard schemes. As control elements 3 and 4, transistors of different conductivity types can be used. As amplifiers 5 and 6, the mismatch can be applied to standard microelectronic amplifiers made in the same package (for example, K15.7UD2 or another type)., I

Parametric voltage regulator 7 (8) can be made in the form of a zener diode 41 (42) connected through a resistor 19 (20) to an output terminal 44 (46) and a voltage divider formed by resistors 13-15 (16-18). ) connected between the common bus and the connection point of the stabilizer; 1) it is 41 (42) with a resistor 19 (20). This point serves as the first 48 (49) output of the parametric stabilizer 7 (8). The resistor 14 (17) is made adjustable, the output of the movable element of this resistor is the second 50 (51) output of the parametric stabilizer 7 (8). Between output 50 (51) and the common bus, a capacitor 29 is turned on (30

The bipolar source of voltage X works as follows.

After turning on the power of the rectifiers 1 and 2, the transistors 3 and 4 are opened by the current flowing through the resistors 9 and 10, ensuring the start of the source; power supply. SPD voltage at terminals 44 (46) when driving the voltage on the outputs 48 and 50 of the parametric stabilizer 7 (at the outputs 49 and 51 of the stabilizer 8) and at the output of the voltage divider formed by resistors 21, 22 (23, 24). The voltage from the output 48 (49) of the parametric stabilizer 7 (8) by the error amplifier 5 (6) is compared with the voltage at the output of the voltage divider formed by the resistors 21, 22 (23, 24). The error signal from the output of the amplifier 5 (6) enters the control electrode circuit

3 1 of element 3 (4), thereby regulating the output voltage level at terminal 44 (46). Simultaneously, the output 50 (51) relieves voltage to the output terminal 43 (47) of the source. Thus, the proposed source provides two pairs of symmetrical with respect to the common bus outputs - 43, 44 and 46, 47 with respect to the clamp 45.

Capacitor 37 (38) is necessary to ensure the stability of the power source. Capacitors 31 and 33 (32 and 34) exclude self-excitation of amplifier 5 (6) at high frequency. The capacitor 29 (30) is designed to reduce the level of noise (pickup) at a frequency.

Diode 39 (40) after the output source. the mode (in the steady state) directly connects the output of the amplifier 5 (6) to the control electrode of the regulating element 3i (4), which increases the negative feedback ratio due to the fact that

the signal from the output of the amplifier 5 (6) post- 25 with the corresponding output outputs through the direct resistance of the diode to the common bus and the first output 39 (40), min resistor 11 (12).

Since the amplifiers 5 and 6 of the mismatch are powered by the output terminals 44 and 46, the output voltage of these

connected to the output terminal of the opposite channel, it is different from that with the aim of increasing

neither stability nor simplification, a voltage divider, a filter, three resistors, two capacitors and a diode are inserted into each channel - the first opposite polarity of the terminals are connected to the input outputs of the control elements of their channel, the output terminals of which are connected to the common bus The second opposite polarity terminals of the amplifiers are connected to the corresponding output terminal of each channel, in each channel the non-inverting input of the error amplifier is connected to the output of a voltage divider connected between the output terminal your channel and shared bus

amplifiers may differ from the output voltage levels + U and -U. ,,,,.

pblK. . jr1a .1

by a small amount (about 1 V

therefore, the voltage value at the output of the rectifiers 1 and 2 may differ from the value of the output voltages at the terminals 44 and 47 by a small amount, i.e. the voltage drop across the regulating element may be very small (about 1 V), which ensures a high efficiency of the source.

In the proposed source, the possibility of the occurrence of positive feedback is excluded, which makes it possible to apply an error amplifier with a gain of about 10 and thereby sharply increase the stabilization factor and reduce the level of output voltage ripple.

The power supply circuits of the misalignment amplifiers in a bipolar source are combined, which makes it possible to use one chip, i.e. simplify the source. In addition, the improvement of the proposed device due to the elimination of the need

13

use of a special power source and current generator.

The temperature coefficient of the proposed device is determined only by the temperature coefficient of the Zener diode and resistors .fi can be at least 10 times lower than the prototype. I

In addition, in the proposed source, the error amplifiers are powered by the output voltage stabilized, which also contributes to an increase in stability and a decrease in the output voltage ripple.

Claims (1)

Invention Formula A bipolar reference voltage source containing two channels, each of which includes a rectifier, an error amplifier, a regulating element, a parametric voltage regulator, an included  the corresponding output of the output is up to the common bus and the first exit connected to the output terminal of the opposite channel, it is different from that with the aim of increasing neither stability nor simplification, a voltage divider, a filter, three resistors, two capacitors and a diode are inserted into each channel - the first opposite polarity of the terminals are connected to the input outputs of the control elements of their channel, the output terminals of which are connected to the common bus The second opposite polarity terminals of the amplifiers are connected to the corresponding output terminal of each channel, in each channel the non-inverting input of the error amplifier is connected to the output of a voltage divider connected between the output terminal your channel and shared bus the inverting input of the error amplifier is connected to the second output of a parametric voltage regulator through the first resistor, and the output of the error amplifier through connected in parallel, the second resistor and a diode connected to the control input of the regulating element, which is connected to the input of the same regulating element the power supply circuits of the error amplifiers are combined and connected through the appropriate filter to the first output of the corresponding $ 12412136 channel, non-inverting bus, and inverting the input of the error amplifier through the second capacitor - to its The capacitor is connected to a common output.