SU1272323A1 - Broad-band voltage stabilizer with protection - Google Patents

Abstract

The invention relates to secondary power sources and can be used to create a power supply unit of electronic equipment. The purpose of the invention is to simplify setup and increase reliability by increasing the stability of the actuation current of protection and reduction of the number of elements. The goal is achieved by increasing the voltage of the current sensor 5 with increasing load current. This increases the voltage at the corresponding input of the operational amplifier 7. The latching transistor 6 opens, and shunts the base-emitter junction of its transistor 1, reducing the load current and the output voltage. In the stabilizer, the operation constant is ensured by equalizing zero in the voltage stabilization mode at the input of the feedback amplifier 2. The condition of the operation threshold provides a simple setting that reduces the likelihood of the stabilizer failing. 2 Il. (L go to with lN3 oo

Description

Puti

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

The purpose of the invention is to simplify setup and increase reliability by increasing the stability of the protection response current and reducing the number of elements.

Fig. 1 is a diagram of a wide-range voltage stabilizer with protection; figure 2 - full load characteristics of the stabilizer.

The stabilizer contains a series regulating transistor 1, a feedback amplifier 2, an output voltage divider 3, a first source 4. a reference voltage, a protection node consisting of a current sensor 5, a protection transistor 6, an operational amplifier 7, a second source 8 of a reference voltage consisting of the first 9, second 10 and third 11 resistors.

The stabilizer works as follows.

Until the protection node triggers, the stabilizer is in the output voltage stabilization mode, while the protective transistor 6 is locked by the voltage from the output of the operational amplifier 7. The condition of the stabilizer mode is that the voltage at the output of the voltage divider is equal to zero relative to the output output:

and uon, (ik) -. 0 „

voltage source reference

voltage 4;

divider division ratio 3

stress

Uoni -7UB

1 to

As the discharge current increases, the voltage drop across the current sensor 5 increases. This increases the voltage at the corresponding input of the operational amplifier 7, when this voltage reaches the value Uon2 - the voltage of the second source 8 of the reference voltage, the voltage at the output of the operational amplifier 7 changes its sign to the opposite, opens the protective transistor b, which starts to shunt base-emitter junction of the regulating transistor 1, reducing the load current and output voltage. The stabilizer switches to the protection node operation mode.

Protection node trigger condition

and, Wonj;

Ul KitBKs + KzU

where KI and K2 - the corresponding transfer coefficients of the divider of resistors 9 - P.

Accordingly, until the moment of operation and 0.

Then

Won2 klicp ks

de icp. - current operation of the protection node and

- -g5V

The tripping current is independent of the magnitude of the output voltage.

For the case of the protection node

Won2 K | iHK5 + (1-k) - KUe.).

Then i «3. - short circuit current (i.ykh 0)

Uon2 - Uoni (I -k) K2

Bullpen s -. 1

KiKs

i.e. for the case of ks O

yoft, 2 (i) Uoni

Then

iop, - iop) iax K (1-к),

where Uoni max is the maximum value of the voltage of source 4 of the reference voltage.

In these conditions, always iic.a; icp. In the stabilizer, the constancy of the operation current is ensured by equalizing zero in the voltage stabilization mode Ul at the input of the feedback amplifier 2. The constancy of the threshold provides a simple setting that reduces the likelihood of a stabilizer failing. The stabilizer contains the minimum number of elements, which increases its reliability.

Claims (1)

Invention Formula A wide-range voltage regulator with protection containing an adjustable transistor connected by a power input to the input terminal, a power output 5 through the current sensor to the output terminal, and the control input to the output of the feedback amplifier connected by the first input to the output terminal, and the second input to the output of the output voltage divider connected by the first input to 0 common and not the second to the first output of the first voltage source connected by the second extension to the output terminal, the protection transistor connected by the collector to the control input of the regulating transistor, the emitter to the ay output terminal, and the base to the output of the operational amplifier connected by the first input through a resistor to the point of connection of the current sensor and the power output of the regulating transistor, and the second input to the first output of the second source of the reference voltage connected by the second output to the output terminal, Sistors, characterized in that, in order to simplify tuning and increase reliability, the first input of the operational amplifier is connected through resistors to the output terminal and to the output of the output voltage divider 5. (Kji u) tH FIG. 2