RU1772795C - Dc voltage stabilizer - Google Patents

Abstract

Usage: in power supplies of electronic equipment with increased stability of the output voltage. SUMMARY OF THE INVENTION: the device comprises a transistor control element included in the power bus, seven transistors, a voltage divider, two resistors and a diode. In contrast to the prototype, the device contains a seventh transistor, a diode and a second resistor connected between the emitter of the seventh transistor and the output terminal. In this case, the base of the seventh transistor is connected to the output of the voltage divider, and the collector is connected to the base of the fourth transistor and through the diode to the emitter of the fourth transistor and to the common bus. Thanks to this, it became possible to obtain a temperature independent reference voltage between the base of the seventh transistor and the output terminal of the device. 1 ill.

Description

The device relates to the field of electrical engineering and can be used in power supplies of electronic equipment.

Serial-type constant voltage stabilizers are known which comprise a regulating element, an error signal amplifier, a reference voltage source, and a voltage divider.

A disadvantage of the known devices is the relatively low efficiency, especially at low output voltages, due to the large voltage drop on the regulating element, which can be an EUB, where its voltage is the emitter-base voltage of the transistor.

The closest in technical essence to the proposed device is a constant voltage stabilizer containing a transistor control element connected between the input and output terminals, six transistors, the first, second and third transistors, emitters connected to the input output, the bases to the combined collector the second and fifth transistors, the base of the fifth and sixth transistors are connected to the combined collectors of the first and fourth transistors, the emitter of the fifth transistor through the first res the torus is connected to the output terminal and the emitter of the sixth transistor, the collector of which is connected to the collector of the third transistor and the control input of the transistor control element, as well as a voltage divider connected between the output terminal and the common bus.

The disadvantage of the prototype is the relatively low stability of the output

VI h | GO XI Yu SL

voltage, due to the flow of collector current of the first transistor through a voltage divider, and the collector current of the first transistor can change during operation, for example, when the load current changes, which leads to a change in the output voltage,

The aim of the invention is to increase the stability of the output voltage,

This goal is achieved by the fact that in the device containing the transistor control element connected between the input and output terminals, six transistors, the first, second and third transistors connected by emitters to the input output, the bases to the combined collectors of the second and fifth transistors, the base the first and fourth transistors are connected to the combined collectors of the first and fourth transistors, the emitter of the fifth transistor is connected through the first resistor to the output terminal and emitter of the sixth transistor, coll the vector of which is connected to the collector of the third transistor and the control input of the transistor control element, as well as the voltage divider connected between the output terminal and the common bus, a seventh transistor, a diode and a second resistor are introduced, while the emitter of the seventh transistor is connected to the output terminal through a second resistor , the base is connected to the output of the voltage divider, the collector is connected to the base of the fourth transistor and the anode of the diode, the cathode of which is connected to the emitter of the fourth transistor and to the common bus.

The drawing shows a diagram of the proposed device in accordance with the claims.

The device contains a regulating element 9 connected between the input and output terminals of the stabilizer, transistors 1, 2 and 3, the emitters of which are connected to the input terminal, the base of transistors 1,2 and 3 are connected to the combined collectors of transistors 2 and 5, transistors 4, 5 and 6 while the bases of transistors 5 and 6 are connected to the combined collectors of transistors 1 and 4, the emitter of transistor 5 is connected through a resistor 8 to the output terminal of the stabilizer and emitter of transistor b, the collector of which is connected to the collector of transistor 3 and controls the input ohm regulating member 9, a voltage divider 10 connected between the output terminal and the common bus, the transistor 7, a diode 12 and resistor 11 and the emitter of transistor 11 is connected to the output terminal

0

stabilizer, base - connected to the output of voltage divider 10, the collector is connected to the base of transistor 4 and the anode of diode 12, the cathode of which is connected to the emitter of transistor 4 and to a common bus.

The circuit of figure 1 works as follows: transistors 5 and 6 have different junction areas, then the voltage across resistor 8 is equal to:

5

0

5

0

5

UR8 U eb-U e5 (J) 0)

where U e is the voltage of the base-emitter of the i-ro transistor;

Si is the emitter area of the corresponding transistor;

temperature potential.

Therefore, the collector currents of all transistors are defined as:

fHn (-ff-)

 RT5- (2)

Obviously, the emitter current of transistor 7 is also defined by formula (2) and increases with increasing temperature. Then, the voltage drop across the resistor 11 also increases with temperature, while the voltage 11 eb of the transistor 7 increases, so it is possible to obtain a temperature-independent reference voltage between the base of the transistor 7 and the output terminal of the stabilizer:

Neither

Ss} RB

Uon U / 37 +

rln (-lf)

-) (3)

0

5

0

5

Full thermal compensation is achieved when the semiconductor band gap extrapolated to 0 ° to the band gap (for silicon is 1.205 V). In the proposed device, the destabilizing current through the voltage divider is equal to the base current of the transistor 7, which is significantly less (50 ... 100 times) than the prototype.

It should be noted that the voltage drop on the regulating element in the proposed device does not exceed the same parameter of the prototype.

Thus, the proposed device has a higher stability compared to the prototype and retains the advantages of the latter.

Claims (1)

The claims A DC voltage stabilizer containing a transistor control element connected between the input and output terminals, six transistors, the first, second and third transistors connected by emitters to the input output, the bases to the combined the collectors of the second and fifth transistors, the bases of the fifth and sixth transistors are connected to the combined collectors of the first and fourth transistors, the emitter of the fifth transistor is connected through the first resistor to the output terminal and the emitter of the sixth transistor, the collector of which is connected to the collector of the third transistor and the control input of the transistor control element, as well as a voltage divider connected between the output terminal and the common bus, about t and 0 which, in order to increase the stability of the output voltage, a seventh transistor, a diode and a second resistor are introduced, while the emitter of the seventh transistor is connected to the output terminal through the second resistor, the base is connected to the output of the voltage divider, the collector is connected to the base of the fourth transistor and with the anode of the diode, the cathode of which is connected to the emitter of the fourth transistor and with a common bus. About fix Oh b o o & u