SU1636834A1 - Ac-to-regulated dc voltage converter - Google Patents

Abstract

The invention relates to secondary power sources. The purpose of the invention is to simplify the converter. The goal is achieved by the fact that the output of the divider 9 is connected to the base of the control transistor 8, and the nonlinear element 10 is connected to the input of the control transistor 7. This ensures that the control transistor 7 operates in the key mode. Switching on the regulating transistor 7 occurs twice in one half-period of the supplying alternating voltage of the network. In the other half-period the regulating transistor 7 is open. This is ensured by the fact that a diode of 6 2 Il is connected in series with the transistor.

Description

FC & 1

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15

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

The purpose of the invention is to simplify the converter.

FIG. 1 is a circuit diagram of a converter; Fig. 2 shows plots of voltages of the main points of the circuit.

The converter contains the first rectifier I, consisting of a current-limiting capacitor 2, a capacitor (accumulator 3 and diodes 4, 5, the second1 rectifier on the diode 6, a control transistor 7, a control transistor 8, a voltage divider 9, made on a nonlinear element 10 and a resistor 11, a filter capacitor 12S shunted by a leakage resistor 13, a resistor 14, a coupling diode, 15 pins 16, 17 for connecting an AC voltage, output pins 18, 19.

The first rectifier 1 and the second rectifier on diode 6 are connected to pins 16, 17. The first rectifier output is connected via a resistor 14 to the output of the control transistor 8, the input of which is connected to the output of the voltage divider 9. The output of the second rectifier on diode 6 is connected to the voltage divider 9 and through the regulating transistor 20

thirty.

On the capacitive drive 3, the regulating transistor 7, when the supply voltage is positive, starts to open periodically. The opening of the regulating transistor 7 occurs only in the initial and final portions of the positive half of the supply sinusoid, which is loaded from the capacitive storage 3 through the resistor 14 and the separation diode 15 arrives at its base. As the half-wave of the supply voltage increases, the voltage at the output of the voltage divider 9 increases, which causes the control transistor 8 to turn on at a certain threshold for switching it on.

After switching on the control transistor 8, the isolation diode 15 is locked and the control transistor 7 is locked, since during a capacitive load on the output pins 18, 19, the isolation diode 15 acts as a blocking voltage. This state in the circuit is maintained until the voltage of the half wave of the sinusoid decreases to the value at which the control transistor 8 turns off and the control transistor 7 turns off. The control transistor 7 turns off when the voltage of the sinusoid is approached, which approaches the voltage bone accumulator 3. During the negative half-wave of the sinusoid, the supply voltage 7 to the output terminal 18 of the transforming voltage does not work for

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Potentials on the capacitive storage 3 reg. The switching transistor 7 starts to periodically open at a positive half-wave of the supply voltage. The opening of the regulating transistor 7 occurs only in the initial and final portions of the positive half-wave of the supplying sinusoid, which is loaded from the capacitive storage device 3 through the resistor 14 and the separation diode 15 enters its base. As the half-wave of the supply voltage grows, the voltage at the output of the voltage divider 9 increases, which causes the control transistor 8 to turn on at a certain threshold for switching it on.

After switching on the control transistor 8, the isolation diode 15 is locked and the regulator, the transistor 7, is locked, as the capacitance diode 15 acts upon the capacitive load on the output pins 18, 19. This state in the circuit is maintained until the half-wave voltage of the sinusoid decreases to the value at which the control transistor 8 turns off and the control transistor 7 turns off. The control transistor 7 turns off when the voltage of the sinusoid is approached, on capacitive storage 3. During the negative half-wave of a sinusoid supplying voltage, the circuit does not work for

tel. The input of the regulating transistor 7 is connected via an isolating diode 15 to the collector of the control transistor 8,

FIG. Figure 2a shows the voltage profile of the working half-wave and the current pulses on the collector of the control transistor 7; FIG. 26 shows the voltage at the output terminals 18, 19, in FIG. 2c, the collector current of the control transistor 8; FIG. 2d is the base current of the control transistor 8 and the current through the nonlinear element 10,

The Converter operates as follows.

When a variable voltage is applied to the outputs 16, 17 on the capacitive drive 3, the voltage of positive polarity begins to increase. The capacitance value of this accumulator is selected one to two orders of magnitude higher than the capacitance value of the current-limiting capacitor 2.

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with the exception of the first rectifier 1, since the recharge of the current-limiting capacitor 2 and the partial discharge of capacitive accumulator 3 through the resistor 14, the separation diode 15, the base-emitter transition of the regulating transistor 7 and the resistor 13 occur in it. in such a way that during any phase of the supply voltage, current surges and overvoltages on the output pins 18, 19 are eliminated, and the control transistor 7 always operates in the key mode.

To reduce the power loss at the stage of turning on the transistor 7, 8, a nonlinear element is included in the upper arm of the divider, for example, a variator, which contributes to an increase in the switching speed of the control transistor 8 and a reduction in the power loss in the controlled transistor 7.

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Load voltage

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Tone of transistor 10 tone and voltage divider current 13

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Claims (1)

Formula of the invention i AC to DC stabilized converter containing the first and second rectifiers connected to the terminals for connecting AC voltage, a capacitive storage device is connected to the terminals of the first rectifier, one terminal of the second rectifier is connected via a control transistor to one output terminal connected through a filtering capacitor to another output terminal, a control transistor connected by a collector through an isolation diode to the base of the regulating trans a source, a voltage divider consisting of a series-connected resistor and a nonlinear element, a resistor connected to one terminal of the rectifier by one отлич, characterized in that, for simplicity, the terminals of the first and second rectifiers, the emitter of the control transistor and the free terminal of the resistor of the divider are connected to another output terminal, the output of the divider is connected to the base of the control transistor, its collector is connected to the other output of the resistor, 20 a free terminal of a nonlinear element is connected to one terminal of the second rectifier. Transistor switching voltage 7 a Load voltage Collector current ^ ppngngtpppa 7 4, the output of the first 'and th with other Working half-wave of supply voltage / - + - \ Lower level \ voltage at load \ / l "> \ \ --X_ —A ’The collector current of transistor 10 The base current of the transistor Yu so the voltage divider baristor 13 C-9 "-