SU1597869A1 - D.c.stabilizer - Google Patents

Abstract

The invention relates to electrical engineering and can be used in sources of secondary power supply of electronic equipment. The goal is to increase the temperature stability of the output current of the stabilizer. The device contains a series regulating transistor, a current sensor, the first and second operational amplifiers, the first and second non-thermocompensated zener diodes with current supply resistors, and the first and second voltage dividers. The control transistor, the current sensor in the output circuit, the first voltage divider and the second zener diode form a compensation current regulator. The goal is achieved by the fact that the second differential amplifier, the second voltage divider and the first Zener diode form an auxiliary voltage regulator, the output voltage of which through the first voltage divider is added to the voltage of the current sensor and fed to the input of the first differential amplifier. Moreover, the voltages U ₁ and U _{2 of the} first and second zener diodes and their temperature coefficients γ ₁ and γ _{2 are} connected with the output current J _out and the resistance of the sensor R _{d by the} following condition U ₂ –U ₁ ^. γ ₂ / γ ₁ = J _out ^. R _d . 1 il.

Description

The invention relates to electrical engineering and can be used in sources of secondary power supply of electronic equipment.

The aim of the invention is to increase the temperature stability of the output current of the stabilizer.

The drawing shows a circuit diagram of a DC stabilizer.

The DC stabilizer contains a regulating transistor 1 connected by a collector to the input positive power bus, an emitter to the output positive bus, and a base to the output of the first differential amplifier 2 matching signal, which inverts the input to the middle output of the first voltage divider made resistors 3 and 4, the extreme terminals of which are connected to the extreme terminals of the second voltage divider, made I on resistors 5 and 6, the junction point of which is connected to the inverting input in a second differential amplifier 7, the output of which is connected to the inputs of a voltage divider (the connection point of resistors 3 and 5), a non-inverting input - with an output negative bus combined with the common leads of voltage dividers

ate

;about

00 O5

with

(connection point of resistors 4 and 6) with the negative output of the amplifier 7, with the first output of the current sensor 8 through the first non-compensated reference Zener diode 9, and with the positive input bus combined with the positive supply terminals of amplifiers 2 and 7, through the first current element 10, the negative power output of amplifier 2 is connected to the negative input bus, to the second output terminal of the current sensor B, the non-inverting input of the amplifier 2 is connected to the negative and positive input buses, respectively, through the second Rowan termokompens reference zener 11 and a second voltage driving element 12.

The output current Igj, x of the stabilizer is determined by the expression

tet / f

R (1)

25

and uj is the stabilization voltage, the first and second zener diodes. respectively;

К К4 / (- the transmission coefficient of the first voltage divider 3;

, / (% + Rj) is the transmission coefficient of the second voltage divider; R. -. sensor resistance - 35

ka current 8,

The magnitude of the temperature dependence of the output current 4I.ei, x is defined as

40

/ 31

etix

r -r-K, / Ki

R.

(2)

where l, are the temperature coefficients of the voltages of the first and second zener diodes. The condition for the temperature stability of the output current is

to, / to Ti / r.

Taking into account (3), the value of the output temperature-compensated current is determined by the ratio

(four)

 -flUX

..

R

Expression (4) is valid for positive values of the numerator, which

j you 15

20

25

3

- 35

40

d

about

is performed if the voltage of the first zener diode 9 is somewhat greater than the voltage of the zener diode 11, since the temperature coefficients are y, and are proportional to the values of the voltages of the first and second zener diodes, respectively.

When the voltage U Zener diode is more than 6 V, the coefficient is l. is determined by the formula

;. + 1.25 (and - 6) j.

The current stabilizer works as follows.

Increasing the supply voltage will increase the output current, which will increase the voltage drop on the current sensor 8, which will flow through the first voltage divider to the inverting input of the amplifier 2, the latter will reduce the voltage at the input of the control transistor 1 and, therefore, the current through him and the load to a previously set value.

As the temperature of the medium increases, the voltages at zener diodes 11 and 9, which are fed to opposite inputs of amplifier 2 and mutually compensate, as a result, the output voltage at the output of amplifier 2 does not change, therefore, the output current of the stabilizer does not change.

Thus, the proposed device, in comparison with the known, allows to significantly increase the temperature stability of the output current by introducing a second non-compensated reference Zener diode and a second differential amplifier and observing a certain ratio between the voltages of the Zener diodes with their temperature coefficients and output current values. and current sensor resistance.

Claims (1)

Invention Formula A DC stabilizer, containing a regulating transistor connected by a collector to a positive input power bus, and the base to the output of a first differential amplifier, the inverting input of which is connected to the middle terminal of the first voltage divider, the second 51 voltage divider, current sensor, | included in the emitter circuit of the regulating transistor, the first non-thermally compensated reference Zener diode and the first current supply element, and the cathode of the first non-temperature compensated reference Zener diode connected through the first current reference element with a positive power supply terminal of the first differential amplifier, characterized in that In order to increase the temperature stability of the output current, the second differential amplifier, non-compensated optical amplifier, is additionally introduced into it. A stable Zener diode and current element, the anode of the second no-thermocompensated reference Zener diode is connected to the negative input power bus, with the negative output of the first differential amplifier, with the first output of the current sensor, the second terminal of which is connected to the negative output bus, with the anode of the first no-thermocompensated reference Zener diode , with a negative output power of the second differential amplifier, with common conclusions of the first and second voltage dividers, the output of the second differential the potential amplifier is connected to the input and the terminals of the first and second voltage dividers, the inverting input is with the average output the house of the second voltage divider, non-inverting input - with the cathode of the first no-thermocompensated reference Zener diode; the emitter of the regulating transistor is connected to the positive output bus; power supply terminals of the first and second differential amplifiers and with a positive input power supply, while the voltage is not The compensated reference zener diodes should be selected from the following condition: and. and Gg / G vkg-Kd where and ,, and GA, x voltages of the first and second non-thermocompensated reference zener diodes; temperature coefficients of the first and second non-thermocompensated reference zener diodes; output current stabilizer torus; current sensor resistance. Uef W 2S // f. but, Sch / l eight L bp22