SU758100A1 - Pulsed dc voltage stabilizer - Google Patents

Description

The invention relates to electrical engineering, in particular to secondary power sources, and is intended for use in computing and communications equipment. five

There is a known DC voltage regulator, which contains a key-transistor connected in series and a smoothing 1C0 filter, as well as a control unit connected by a ¹⁰ feedback circuit to the output terminals, and a trigger unit. The output of the control unit is galvanically connected to the key transistor, and the control unit is powered in steady state 15 from the output of the device ^ 1].

The disadvantages of this stabilized. Pa are a significant allocation of excess power in the elements of the control unit in case of high input voltage, due to its galvanic connection with the key transistor, and the inability of the stabilizer to operate when the output voltage is lower than that required for powering the control unit.

a torus connected by one output to the input terminal, and another through serially connected primary winding of the current transformer and 1_ C filter - to the output terminal, with a filter capacitor connected between the output terminal and the common bus, control and protection unit connected by the corresponding inputs to the output terminal, common bus and the secondary winding of the current transformer, and the output through a pulse transformer - to the control terminal of the key transistor £ 2].

Due to the fact that the control and protection unit is powered from the stabilizer input, this device has a significant drawback - in case of a high input voltage, useless power dissipation occurs on the elements of the control and protection unit. This leads to lower efficiency and reliability, and in some cases eliminates the feasibility of using a stabilizer.

In addition, the power supply to the unit

control and protection from the input does not allow building this voltage regulator with the filter switched on Closest to the proposed DC voltage regulator contains a key transistor3

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polar-inverting scheme, which limits its functionality. · The purpose of the invention is to expand the functionality of a pulsed voltage regulator by achieving the independence of its work on the input voltage and on the polarity of the output voltage while increasing reliability and efficiency.

This goal is achieved by introducing a start-up unit, an additional winding on the filter choke, a zener diode and a half-wave rectifier input connected to the additional winding of the filter choke, the zener diode connected between the output terminal and the common bus, and the start block connected between the input terminal and the corresponding polarity of the power terminal of the control and protection unit, also connected to the corresponding output of the half-wave rectifier, the second output of which is connected to another terminal power supply of the control and protection unit and to the output terminal.

FIG. 1 shows a diagram of a pulse voltage regulator with a CSϋ smoothing filter turned on in a polar-inverting circuit; in fig. 2 - the same, according to the noninverting direct scheme.

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The device contains a key transistor 1, a smoothing LCO filter 2 connected in series with it, consisting of choke 3, capacitor 4 and diode 5. A transformer is connected to the collector circuit of key transistor 1

current 6. The choke '3 has an additional winding 7, to which the half-wave rectifier 8 is connected, consisting of a rectifier diode 9 and a conductor 10. The control unit 11 and the shields are connected by their outputs 12 and 13 through a pulse transformer 14.c, which controls the switching junction transistor 1. Inputs 15 and '16 of the control and protection unit 11 are connected to the secondary and winding of the current transformer 6. Inputs 17 and 18 of the control unit 11 are its power terminals, and the input 17, which is the positive power terminal, is connected to the positive terminal 19 half-wave rectifier 8, and input 18, which is the negative power terminal, has a negative half-wave rectifier output 20 8. The stabilizer has two input $$ terminals - negative polarity 21 and positive polarity 22, and two output terminals 23 and 24, with input terminal 22 and output terminal 24 are interconnected. The output terminal 23 is positive polarity, and, 40 the output terminal 24 is negative. The positive power supply terminal 17 of the control and protection unit 11 is connected to the output terminal 23 which is the same with its polarity. Negative input

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Feedback 25 of the control and protection unit 11 is connected to the negative output terminal 24, and the positive feedback input 26 is connected to the positive output terminal 23. The output of the voltage regulator includes a zener diode 27, with its cathode connected to the positive output terminal 23 and the anode to the negative output terminal 24. Between the input negative terminal 21 and the negative power terminal 18 of the control and protection unit 11, the start unit 28 is turned on.

In a non-inverting direct circuit (FIG. 2), the output terminal 2 3 has a negative polarity, and the output terminal 24 is positive, and, accordingly, the positive power terminal 17 of the protection And control unit 11 is connected to the output positive terminal 24; The negative feedback input 25 of the control and protection unit 11 is connected to the output terminal 23, and the positive feedback input 26 is connected to the output terminal 24; the cathode of the Zener diode 27 is connected to the positive output terminal 24, and the anode to the negative output terminal 2 3.

Pulse voltage regulator presented in figure 1, works as follows ..

When DC voltage is applied to input terminals 21 and 22, startup unit 28 supplies power to control and protection unit 11 through the following circuit: plus source, input terminal 22, Zener diode 27, positive 17 and negative 18 power terminals of control and protection unit 11 , start block 28, input terminal 21, source minus (zener diode 27 works like a normal diode). At the same time, the control and protection unit 11 begins to generate control pulses, which from outputs 12.13 through a pulse transformer 14 are fed to the control transition of a key transistor 1. Key transistor 1 starts periodically connecting a smoothing UO filter 2 to the input voltage source, resulting in the output terminals 23,24 appears the output voltage, which is fed to the feedback inputs 25 and 26 of the block 11 control and protection. The zener diode enters normal operation. At the same time on the additional winding 7 of the choke 3, bipolar rectangular pulses appear. The rectifying diode 9 is opened at the closed-state intervals of the key transistor 1, and the capacitor 10 is charged to the amplitude of the pulses fed to it, which is proportional to the amplitude of the stabilized output voltage. So, at outputs 19 and

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20 half-wave rectifier 8 appears stable voltage, which is supplied to the power terminals 17,

18 unit 11 of control and protection. After supplying voltage to the control and protection unit 11, the start-up unit 5 28 is disconnected and thereby breaks the circuit connecting the power supply terminal 18 of the control and protection unit 11 and the input terminal 21. The Zener diode 27 is closed, as it has an output the voltage in the opposite direction, but insufficient in magnitude for the emergence of the Zener Surge.

In the case of an emergency increase in the output voltage of the stabilizer, the pre-5 output value of the breakdown voltage of the Zener diode 27, the latter breaks through. This dramatically increases the amplitude of the current pulses flowing through the key transistor 1. Information about the increase of this current through the current transformer 6 is fed to the inputs 15, 16 of the control and protection unit 11, which disconnects the voltage regulator. 25

In the case of an emergency change in the polarity of the output voltage, for example, in the event of a breakdown or short-circuit of diode 5, a voltage is applied to the zener diode 27 in the forward direction, while the zener diode operates ³⁰ as a normal diode. This, on the one hand, leads to the operation of the protection (as described above), and on the other hand, limits the voltage of opposite polarity on the 35 output terminals 23, 24 to be safe for the consumer.

The operation of a pulsed voltage regulator with a 1.C0 smoothing filter included in a direct circuit, shown in Fig. 2, is similar to the circuit in Fig. 1, except that when DC voltage is applied to the input terminals 21,22 The starting unit 28 supplies 45 voltage to the control and protection unit 11 along the circuit: plus source, input -. terminal 22, positive 17 and negative 18 power terminals of the control and protection unit 11, startup unit 28, 50 input terminal 21, minus the source.

The use of a new start-up unit, an additional winding of a power choke with a half-wave rectifier and a zener diode — distinguishes 55 the proposed pulsed voltage regulator from the known ones, since the stabilizer is independent of the input voltage, i.e. There is no useless power dissipation on the elements of the control and protection device in case of a high input voltage value, which allows to increase the efficiency and reliability of the voltage regulator; it is possible to build a voltage stabilizer using the same nodes and elements both according to the scheme with the HCL filter connected in a direct scheme, and with the USC filter connected in a polar-inverting scheme, which expands the field of application of these devices and eliminates the need development of new voltage regulators with a polar-inverting output? in addition, the output voltage in the stabilizers is limited in emergency situations, which improves their reliability.

Claims (1)

Claim A dc voltage regulator containing a key transistor connected by one output to an input terminal and the other through a primary winding of a current transformer connected in series and a bc 0 filter to an output terminal, with a filter capacitor connected between the output terminal and the common bus, control and protection unit connected by the corresponding inputs to the output terminal, the common bus and the secondary winding of the current transformer, and the output through the pulse transformer - to the control terminal of the key transit A story, characterized in that, in order to extend the functionality by achieving independence of the operation of the switching regulator from the input voltage and the output voltage polarity while increasing reliability and efficiency, a start-up unit, additional winding on the filter choke, a Zener diode and a full-wave rectifier are introduced into it, the input is connected to the additional winding of the filter choke, with the zener diode connected between the output terminal and the common bus and the start-up unit connected between the input terminal It is connected to the corresponding output of the half-wave rectifier, the second output of which is connected to another power terminal of the control and protection unit and to the output terminal.