SU1287131A1 - D.c.voltage stabilizer with protection - Google Patents

Abstract

The invention relates to electrical engineering and can be used in stabilized secondary power sources. The aim of the invention is to increase the effectiveness of the protection by providing self-resetting after the disappearance of the overcurrent. When an overload occurs from the sensor, the current 4 is removed and the trigger 5 switches off the regulating element 1. If the load resistance increases, as determined by node 9, the regulating element 1 is turned on and the trigger 5 is reset. 2 hp f-ly, 1 ill.

Description

(L

Yu

00

about

eleven

The invention relates to electrical engineering and can be used to power radio devices and test equipment.

The aim of the invention is to increase the effectiveness of protection by ensuring self-resetting after the disappearance of the overload.

The drawing shows a functional DC voltage regulator circuit with protection.

The stabilizer contains a regulating element 1, to the control input of which a feedback measuring amplifier 2 is connected, stabilizing HanpHKeHHsr at the output of the device. The overload protection unit 3 consists of the resistor 1E sensor 4 of the current connected to the input of the RS flip-flop 5, the first output of the flip-flop 5 is connected to the input of the first key element b, the output of which is connected to the control input of the regulating member 1. To the second output of the flip-flop 5 in series a delay element 7, a second two-key key element 8, a load resistance measuring node 9 and a trigger reset terminal 10 5 are connected to the first output, trigger 5 is connected to the second control input of the second key element 8, the output of the second key element 8 is connected to the second input of the reset unit 10. The output ys of the measurement pa 9 is connected to the common bus 115; output terminal 12 is connected to the current sensors 4 and is common to the supply terminal of the protection unit 3. Delay element 7 is required for receiving delays of switching on the node 9 of measuring the load resistance relative to the moment of triggering of the trigger 5 at overload to eliminate the influence of transients on the operation of the node 9 measuring the load resistance. The second key element 8 is the decoupling and matching element between the delay element 7 and the resistance measuring unit 9 ;; it is loaded and serves to control the operation of the latter. The resistance measuring unit 9 consists of a key trazistor 13, the base of which is connected via a current-setting resistor 14 to the output of the second key element 8p emitter — to the first input of the resetting unit 10 and through a load resistor

five

71

five

 -

-

five

0

312

15 to the power bus node protection 3. The collector of the transistor 13 is the output of node 9 and is connected to the common bus 11. The reset node 10 consists of elements II - KE 16 and 17. The output of the reset node is the output of element 17, which is connected to the reset input of the trigger 5.

The device works as follows.

When the stabilizer operates in the stabilization mode and there is no overcurrent, the voltage drop from the load current on the sensor 4 is not enough to trigger the trigger 5.

The initial state of the trigger 5 is the state of logical O at the first output and the state of logic at the second input. When the load resistance decreases, the load current increases, and at a certain value of it, the voltage drop on the current sensor 4 becomes sufficient for trip-5 to operate, it switches. 1Key element 6 goes to the open state and shunts the control input of the regulating element 1J, turning off the stabilizer o Simultaneously MeHHio starts working the delay element 7 and after the delay time determined by the capacitor 18 and selected longer duration of transition: stabilizer J processes, 1 zcl It is the key element 8 which includes the key transistor 13, connecting the resistance to the load to the reset node 10. At the same time, the measuring current flows through the resistance of the load, which is determined by the value: the resistance of the resistor 15 ,. Since the resistance is not high, it is not enough that the sum of the voltage drops on the open transistor 13 and on the load resistance is insufficient to trigger the reset node, then the stabilizer is off and H8 can go for a long time in this state. When the cause of the overload is eliminated, the load resistance increases even at value, even MeKbineMj than “at the emitter of the transistor 13 is formed voltage logical H. If there is a reset node 10 at the first input of the transistor 13p connected to the e-speaker i % a at the second input is connected with the output of the second key element 8 of the voltage.

one

O, at the output of the reset circuit, the voltage of the logic O is generated, which switches the trigger 5 to the initial state. The trigger 5 turns off the key element 6, which turns on the regulating element 1. At the same time, the trigger 5 turns off the second key element 8, thereby disabling the load resistance measuring unit 9. The protection node 3 returns to the original connection and the stabilizer starts to operate in the output voltage stabilization mode,

The load resistance measurement assembly 9 can be performed on the base of a comparator or on an operational amplifier.

Thanks to the introduction of new elements and their connections, a self-return function is implemented in the stabilizer circuit with protection when the regulating element is turned off, and this increases the protection efficiency of the stabilizer, since their implementation gives a complete shutdown of the reversing element Ta with ensuring the subsequent self-return.

Claims (3)

1. A direct voltage stabilizer with protection containing a regulating element included in one of the power buses, a feedback measuring and amplifying node connected to the common bus with an input to the output terminal, and an output to the control input of the regulating element, and a protection unit overload, short-circuit of the trigger, resistive current connected to the power bus and connected to the trigger input, and the first key element connected to the primary 50 five 0 five 0 five 0 314 the trigger output, and the output to the control input of the regulating element, characterized in that, in order to increase protection efficiency by ensuring self-return after the overload j disappears, the stabilizer load sensing unit, the trigger reset unit, and the second two-input key element, wherein the common power output of the protection unit is connected to the output output and the current sensor, the output of the measuring unit is connected to the common pin, its load output is connected to the first input of the reset unit, Ora input coupled to an output of the second key member and the input of the measurement unit, the reset unit output is connected to the reset input of the flip-flop, the second output of which is connected via a delay element to one input of the second key member, the other input of which is connected to the first:. Exit trigger 2, the stabilizer according to claim 1, which differs from the fact that the load resistance measuring node consists of a key transistor whose collector is connected to the output, the base through the first resistor is to the input, and the emitter is to the load terminal and through the second resistor is with the supply terminal of the protection unit, 3.Stabilizer according to claim 1, 1, o tl - the fact that the node measuring the resistance of the load of the stabilizer consists of a key transistor, the base of which is connected to the input of this node through the current-setting resistor, the emitter is connected to the output of the load and - to the output of the power node, and the collector to the output of this node.