SU714377A1 - Dc voltage stabilizer - Google Patents

Description

(54) CONSTANT VOLTAGE STABILIZER

one

The invention relates to electrical radio engineering, namely, power sources, and can be used in power supply systems of automation devices and computing.

DC voltage regulators are known that contain a regulating transistor, a resistor divider, an error signal amplifier, and a reference voltage source C1.

The closest to the technical essence of the invention is a DC voltage regulator containing a control transistor connected in series to the output bus, an emitter connected to the output terminal, a resistor divider connected to the output terminals, the error signal amplifier connected to one of the input terminals voltage 2.

The disadvantage of this stabilizer is that it has a long time to establish a transient gf process when measuring the reference voltage.

The aim of the invention is to improve the dynamic characteristics.

This is achieved by the fact that in a constant voltage regulator, the content of a regulating transistor connected by an emitter connected to an output terminal connected in series to an output bus, is connected to a resistor divider, an error signal amplifier, which is connected to one of the output terminals the base of the regulating transistor is connected to the common side through a series-connected two-port and the mentioned signal amplifier The connection, to the point of connection of which the base is connected, is an additionally inserted transistor, an emitter connected to the emitter of the regulating transistor, and a collector with a common bus.

The drawing shows an electrical circuit of a constant voltage regulator.

The stabilizer contains a regulating transistor 1, a resistor divider 2 and 3,

error signal amplifier 4, voltage source 5, two-port 6, transistor 7, resistor 8, capacitor 9 and load 10.

The device works as follows.

With an abrupt increase in the reference voltage or an abrupt decrease in the transfer coefficient of the resistive divider, the charge of the output correction capacitor occurs from a small time constant:

T, "Cj (R, -fRi) (1)

where Ri is the internal resistance of the regulating transistor when switched on in a common base;

RI-internal resistance rec.

On the other hand, the discharge of the correction capacitor with an abrupt decrease in the reference voltage occurs when the control transistor is locked through the load RM and the resistive divider. The control transistor remains locked for the entire duration of the capacitor discharge. The output voltage varies exponentially:

V (t) Vo / l-exp - A), (2)

GOLD S, -5 “-il l. | detz z

Kg-resistance of a voltage divider connected in parallel with the load;

RH is the stabilizer load resistance.

To increase the efficiency of the stabilizer, the resistance is chosen sufficiently large. Consequently, under a high-resistance RH load, the transition process in the stabilizer is delayed, since

(3)

In the steady state, the current in the load is provided mainly by the regulating transistor 1. The auxiliary transistor 7 is in the mode close to the cutoff mode. This position of the operating point of the transistor 7 is established by a two-port 6.

With an abrupt increase in the reference voltage from the -Ei level to the ti level, the transient time is minimal. The stabilizer fulfills the disturbance with a constant, which is defined by the formula (1)

If the voltage of source 5 decreases from - to -If 50 mV, then transistor 1 enters the cut-off and transistor 7, on the contrary - into active mode. The emitter current of transistor 7 quickly recharges capacitor 9. The output voltage of the stabilizer decreases exponentially:

V (t) Vo (l-exp- | -) (4)

where ta C3-R7;

Ry is the internal resistance of the transistor 7 when switched on according to the common base circuit.

Since Rr is small, the transition time (4) will also be small. Thus, the response of the stabilizer when switching from a higher level of stabilized voltage to a lower voltage is much higher. This improves the dynamic parameters of measurement systems using programmable power supplies.

Claims (2)

1.Vinogradov Yu.V. Fundamentals of electronic and semiconductor technology, M., “Energie, 1968, p. 559, fig. 15-6. 2. Shtilman V. I. Microelectronic voltage stabilizers, Kiev, 1976, p. 123, fig. thirty.