RU2076443C1 - Single-cycle stabilizing direct voltage converter - Google Patents

Abstract

FIELD: secondary power supply units for radio engineering equipment, efficient high-voltage power supply for mobile devices. SUBSTANCE: device has direct voltage power supply 1, inductance accumulator 2, gate 3, rectifier 4, controlled modulator 5, threshold unit 6, reference voltage source 7, two resistors 8 and 10, capacitor 11 and diode 12. Device provides pulse operating mode for reference voltage source 7 for low average current. EFFECT: increased reliability, decreased cost. 2 dwg

Description

 The invention relates to a conversion technique, in particular to sources of secondary power supply of electronic equipment, and can find application as an economical source of high voltage, especially in portable equipment.

 Known stabilizing single-cycle DC-DC converters, the basis of which are an inductive storage, electronic key, feedback circuit, a pulse control circuit of an electronic key (modulator) and a rectifier (usually a diode).

 Known single-phase stabilizing DC-DC converter, made according to the scheme of the oscillator with "reverse diode", containing a key transistor, the control output of which is connected through a limiting resistor to the feedback winding and to the output of the threshold node, consisting of two transistors of different conductivity types and four resistors, moreover, the emitter of the first transistor is connected to the input terminal of the converter, and the collector through the first resistor with the base of the second transistor, the emitter of which connected to the common terminal of the converter, and a second resistor is connected between the emitter of the first and the collector of the second transistor, the collector of the second transistor forms the output of the threshold node, and the base of its first input, to which one of the terminals of the third resistor is connected.

 In this converter, in order to increase the efficiency by eliminating the consumption current in the off state of the oscillator, an adjustable reference current source is introduced, which is included at the input of the threshold node, which forms a Schmitt trigger by turning on the fourth resistor between the collector of the second and the base of the first transistors, and the second output of the third a resistor is connected to the output terminal.

 The disadvantage of this converter is a decrease in efficiency, reliability and cost increase when powering high-voltage high-resistance circuits. This is due to the fact that the output of the converter is connected via direct current through a feedback resistor to a source of controlled adjustable current and Schmitt trigger transistor circuits. Feedback current flows continuously and must be at least some minimum value sufficient to ensure the operability of the converter. With high-resistance loads and high voltages, the power lost in the feedback circuit is a significant fraction of the useful power, i.e., the efficiency of the converter is significantly reduced. With a decrease in the feedback current, the requirements for the converter circuit elements increase, the cost of its manufacture and tuning, and the reliability of operation decreases.

 The purpose of the invention is to increase reliability and reduce the cost of the converter by providing a nominal operating mode and interchangeability of radio electronic elements without additional rejection.

 The goal is achieved by the fact that into a single-cycle stabilizing DC-DC converter containing input terminals, one of which is connected to the first terminal of the inductive storage, the other terminal of which is connected to the input of the rectifier, the second terminal of the rectifier is connected to one of the output terminals, the second output terminal is connected to one a power output of the electronic key and another input terminal, a reference voltage source, the first terminal of which is connected through the first resistor to the second input terminal, a threshold node, input to The other is connected to the connection point of the first output of the reference voltage source and the first resistor, and the output is connected to the input of a controlled modulator, the output of which is connected to the control input of the electronic key, a diode is introduced, as well as a second resistor and capacitor connected in parallel, connected by one of the outputs to the second input output and other leads are connected to the input of the threshold node and through the diode to the connection point of the first output of the reference voltage source with the first output of the first resistor, the second output is the source a reference voltage connected to a connection point of another power electronic key derivation and output of the intermediate inductive storage, constructed in the form of an autotransformer.

 In FIG. 1 schematically shows one of the possible versions of the Converter.

In FIG. 1 and 2, the following notation is accepted:
1 input pins;
2 inductive storage;
3 electronic key;
4 rectifier;
5 control modulator;
6 threshold node;
7 reference voltage source;
8 first resistor;
9 output conclusions;
10 second resistor;
11 capacitor;
12 diode;
13 master oscillator;
14 logical circuit 2 OR NOT.

 The converter operates as follows.

At the time of supplying voltage to the input terminals from the power source, all the voltages and currents in the circuits of FIG. 1 and 2 are zero. When the voltage level on the capacitor 11 is lower than the threshold threshold for switching the threshold node, the signal from the last one is output, allowing pulses to pass from the modulator 5 to control the key 3. In this case, the first control pulse provides the open state of the key 3 for the time determined by the generator 13 of the modulator 5. During of this time, a linearly increasing current begins to flow through a part of the winding of the inductive storage 2 connected to the output terminals 1
I = U _o t / L,
where U _{o the} voltage of the power source;
L winding inductance;
t time.

At time T _and (at the end of the modulator pulse), switch 3 closes and the current of inductive storage 2 starts flowing through rectifier 4 to output 9. If during the first pulse the voltage at the first output of switch 3 does not reach the level of stabilization of the reference voltage source (for example, with a capacitive load ), the potential at the input of the threshold node 6 is less than its reset threshold and the modulator 5 after a pause produces the next pulse and then the process is repeated until the output voltage of the switch 3 exceeds um, the breakdown level of the reference voltage source and the current begins to flow, charging the capacitor 11 through the diode 12. After the voltage on the capacitor 11 exceeds the switching threshold of the threshold node 6, the latter generates a potential that stops the supply of opening pulses from the modulator 5 to the input of the key 3. Key 3 remains closed for the duration of the discharge of the capacitor 11 through the resistor 10. After the voltage across the capacitor 11 drops to the switching level of the threshold node 6, the latter allows passage with latter is present from the modulator 5 with a key 3, and further processes proceed similarly. The discharge time constant of the capacitor 11 is selected less than the time constant in the load circuit. Therefore, fluctuations (ripple) of the output voltage can be provided sufficiently small. In this case, the average output voltage level will be determined by
U _o = (U _op + U _p ) K ₁ K ₂ ,
where U _{op the} level of the reference voltage;
U _{p the} threshold threshold node (usually U _p <U _op );
K ₁ gear ratio of inductive storage;
K ₂ gear ratio of the rectifier.

Since the value of U _op , K ₁ , K ₂ stable, and U _p <U _{op the} output voltage of the Converter is supported with sufficient stability. The current through the reference voltage source is close to the range of nominal values and flows only for short time intervals, therefore, the claimed solution has higher reliability compared to the prototype and does not require the selection of electro-radio elements, which reduces the cost of its manufacture.

Claims (1)

 A single-phase stabilizing DC-DC converter containing input terminals, one of which is connected to the first terminal of the inductive storage, the other terminal of which is connected to the input of the rectifier, the second terminal of the rectifier is connected to one of the output terminals, the second output terminal with one power output of the electronic key and the other input output, the reference voltage source, the first output of which is connected through the first resistor to the second input terminal, a threshold node, the input of which is connected to the connection point the first output of the reference voltage source and the first resistor, and the output is connected to the input of a controlled modulator, the output of which is connected to the control input of the electronic key, characterized in that, in order to increase reliability and reduce the cost of the converter, a diode is introduced, as well as a second resistor connected in parallel and a capacitor connected by one terminal to the second input terminal, and other terminals to the input of the threshold node and through the diode to the connection point of the first terminal of the reference voltage source with the first terminal a first resistor, a second terminal of the reference voltage source is connected to a connection point of another power electronic key derivation and output of the intermediate inductive storage, constructed in the form of an autotransformer.

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