RU1815628C - Switching stabilizer of direct voltage - Google Patents

Abstract

Usage: in secondary power supplies. SUMMARY OF THE INVENTION: the stabilizer comprises a control transistor (1), an LCD filter (2, 3, 4). control unit Ш .. 16 1 (5), OR gate (6), comparators (7,11), reference voltage sources (8, 9, 10) output voltage divider on resistors (12, 13), semiconductor switch (14) capacitor

Description

The invention relates to electrical engineering and can be used in secondary power supplies.

The purpose of the invention is to increase the operational reliability of the power supply system - electronic load by providing protection of the load against overvoltage.

The drawing shows a functional diagram of the proposed key constant voltage stabilizer.

The DC voltage regulator includes a control transistor 1, which is connected to the output terminal via a choke 2, and a capacitor 3 is connected between the output terminal and the common bus. A diode 4 is connected between the connection point of the emitter of the control transistor 1 and the choke 2 and the common bus. The interconnection diagram of choke 2, capacitor a 3 and diode 4 is an ICD filter. The output of the control unit 5 is connected to the first input of the OR element 6, the second input of which is connected to the output of the lower level comparator 7, and the output is connected to the base of the control transistor 1. The reference voltage source 8 is connected between the non-inverting input of the control unit 5 and the common bus. A first additional voltage reference source 9 is connected between the non-inverting input of the lower level comparator 7 and the common bus. A second additional voltage reference source 10 is connected between the inverting input of the upper level comparator 11 and the common bus. The first and second resistors 12 and 13 of the output voltage divider are connected to each other in series, the second terminals of which are connected between the output terminal and the common bus, and the connection point is to the inverting input of the control unit 5, the first switch 14 is connected in parallel to the resistor 13, the control input which is connected to the output of the upper level comparator 11. The capacitor 15 is connected in parallel with the resistor 12. The inverting input of the lower level comparator 7 and the non-inverting input of the upper level comparator 11 are simultaneously connected to the output terminal, to which one of the outputs of the first key 14 is connected. The key stabilizer also contains a fuse 16, thyristor 17, inverters , RC integrator 19, zener diode 20, third resistor 21, first 22, and second 23 additional keys, the control inputs of which second 22 are directly, and the third 23 are connected to the output of comparator 1 through inverter 18 1 top level The first output of the second key 22 is connected to the output terminal, and the second through a series-connected zener diode 20 and a resistor 21 to a common bus, to

which simultaneously connects the capacitive output of the RC integrator 19. The first output of the thyristor 17 and through the third key 23 simultaneously the control output of the thyristor 17 and the output of the RC integrator 19, the resistive output of which is connected to the connection point of the zener diode 20 and resistor 21, the second output of the thyristor 17 is simultaneously connected to the collector of the control transistor 1 and through a fuse 16 to

input pin.

The stabilizer works as follows.

Comparators of the upper 11 and lower 7 thresholds

by selecting the reference voltages of the sources 9 and 10, the reference voltages are adjusted respectively to the upper and lower boundaries of the zone of permissible spread of the output voltage.

When the output voltage of the stabilizer is in the range of acceptable spread, the comparators 7 and 11 are in the initial state; which is characterized by the absence of an output signal,

those. in the initial position, the outputs of both comparators have signals corresponding to logical O. Logical O at the output of the comparator 11 of the upper threshold is closing for

keys 14 and 22 and, accordingly, these keys are closed. At the same time, at the output of the inverter 18 there is a logic 1 signal, which is opening for the key 23 and the key 23 is open and shunts the output of the RC integrator 19. When the comparator 7 logically goes out 0, the lower threshold of operation is controlled by the signal from the output of the control unit 5, and to the circuit regulation input

transistor 1, LCD filter elements 2-4, first 13 and second 12 resistors of the output voltage divider, capacitor 15, control unit 5, reference voltage source 8 and OR element 6. The stabilizer operates conventionally.

If the output voltage drops below the lower boundary of the zone of permissible spread, the comparator 7 of the lower threshold is triggered and a logical 1m signal appears at its output. This signal is fed to the input of element b and provides a logical T signal at its output for any signal at its input, ensuring the development of this disturbance. So

as this control loop does not contain inertial elements, its speed is great.

If the output voltage exceeds the upper limit of the zone of permissible spread, the comparator 11 of the upper threshold is triggered and a logic signal G appears at its output, which is opening for the key 14, which opens and shunts the first resistor 13 of the output voltage divider . The perturbation signal from the output of the stabilizer through the public switch 14 directly goes to the input of the control unit 5, thereby increasing the speed of the stabilizer, since the dynamic resistance of the key 14 in the open state is much less than the resistance of the first resistor 13 of the output voltage divider. Further development of such a disturbance occurs traditionally.

When breakdown of the control transistor 1, the voltage at the output of the stabilizer increases and the maximum permissible value passes. Similarly to the previous case, the logic G signal is set at the output of the comparator 11, and the logical O signal is installed on the inverter 18, which put the keys 14 and 22 into the open state and 23 into the closed state. Through the open key 22, the zener diode 20 is unlocked and a current flows through the resistor 21, which creates a voltage drop across it, which, passing through the RC integrator 19, enters the control terminal of the thyristor 17 and unlocks the latter. The input terminal - fuse 16 - open thyristor 17 - circuits the current through the circuit, which burns out the fuse and disconnects the primary power circuit from the stabilizer; an RC integrator is necessary to prevent false triggering of the protection circuit from creating pulsed noise.

Thus, the load is protected in the event of an overvoltage at the output of the proposed device.

Formula, Inventions /

A key constant voltage regulator, comprising a control transistor connected between the input terminal and the first output of the LCD filter throttle, an output voltage divider made on the first and second resistors, the first output of the first resistor connected to the output terminal, the second

the output of the LCD filter interconnector and the positive output of the LCD filter capacitor, and the first output of the second resistor with a common bus, negative capacitor output and the 5th anode of the LCD filter diode, the cathode of which is connected to the first output of the LCD filter interconnector, a control unit, an inverting input which is connected to the midpoint of the output voltage divider formed by connecting the second terminals of the first and second resistors, and the non-inverting input through the reference voltage source is connected to a common bus, a capacitor connected in parallel toromu resistor divider output. semiconductor voltage

key connected in parallel to the first

resistor output voltage divider

two comparators and two additional sources of reference voltage, the non-inverting input of the first comparator and the inverting input of the second comparator connected to the output terminal, inverting the input of the first comparator through

5, the first additional reference voltage source, and the non-inverting input of the second comparator through the second additional reference voltage source connected to a common bus, the output of the first

0 of the comparator is connected to the control input of the semiconductor key, an OR gate, the first and second inputs of which are connected respectively to the output of the second comparator and to the output of the node

5 control, and the output is connected to the control input of the control transistor, characterized in that, in order to increase operational reliability by providing protection of the load against overvoltage, a fuse, a thyristor, are introduced into it. inverter, RC integrator, zener diode, third resistor, first and second additional keys, the first output of the first additional key

5 is connected to the output terminal, and the second output through a zener diode and a third resistor connected in series with a common bus, a second additional switch, the shunt output of the RC integrator is on

0 between the base of the control transistor and the common bus, and the control inputs of the first additional switch are directly connected, and the second additional switch through the inverter is connected to the output of the first switch, the connection of the control transistor with the input terminal is made through a fuse, the thyristor is connected between the common point of the fuse with control transistor and about 71815628 8

by a bus, the thyristor factory controlling the zener diode connection point with the third is connected to the base of the regulating transistor, the store, and the input of the RC integrator is connected to