SU964607A1

SU964607A1 - Overload-protected voltage stabilizer

Info

Publication number: SU964607A1
Application number: SU803006570A
Authority: SU
Inventors: Алексей Владимирович Воробьев
Original assignee: Предприятие П/Я М-5619
Priority date: 1980-11-24
Filing date: 1980-11-24
Publication date: 1982-10-07

Description

Изобретение относится к стабилизированным источникам электропитания.The invention relates to stabilized power supplies.

Известен стабилизатор напряжения, содержащий регулирующий транзистор, подключенный эмиттером к входному выводу, а коллектором - к выходному, 5 усилитель обратной связи, делитель выходного напряжения, источник опорного напряжения, запитанный с выхода стабилизатора, и узел защиты стабилизатора [ 1 ]. ^,с Known voltage stabilizer containing a control transistor connected by an emitter to the input output, and the collector to the output, 5 feedback amplifier, output voltage divider, voltage reference source, powered from the output of the stabilizer, and the stabilizer protection unit [1]. ^,from

Недостатком его является значительная сложность узла защиты от перегрузок.Its disadvantage is the significant complexity of the overload protection node.

Наиболее близким к изобретению по технической сущности является стабилизатор напряжения с защитой от пере- . грузок, содержащий регулирующий транзистор, эмиттер которого соединен, с входным, а коллектор связан с выходным выводами, Усилитель обратной связи, выходом соединенный с базой регулирующего транзистора, источник опорного напряжения на стабилитроне и ог-:Closest to the invention in technical essence is a voltage stabilizer with protection against over-. a load containing a control transistor, the emitter of which is connected to the input, and the collector is connected to the output terminals, feedback amplifier, output connected to the base of the control transistor, the voltage reference source on the zener diode and og-:

' ' раничительном резисторе и делитель выходного напряжения не> двух резисторах, средние выводы которых подключены к входам усилителя обратной связи, крайние выводы стабилитрона и одного из резисторов делителя соединены с, общей шиной , а крайние выводы ограничительного резистора и другого из резисторов Делителя связаны с выходным выводом стабилизатора, датчик Тока, включенный в одну из силовых шин [2 ].'' the boundary resistor and the output voltage divider are not> two resistors, the middle terminals of which are connected to the inputs of the feedback amplifier, the extreme terminals of the zener diode and one of the resistors of the divider are connected to the common bus, and the extreme terminals of the limiting resistor and the other of the resistors of the Divider are connected to the output the output of the stabilizer, a Current sensor included in one of the power buses [2].

Недостатком известного устройства является низкая эффективность защиты, заключающаяся в большом влиянии защиты на стабильность выходного напряжения, и в значительной нестабильности порога срабатывания зашиты.A disadvantage of the known device is the low efficiency of protection, which consists in a large influence of protection on the stability of the output voltage, and in a significant instability of the threshold of protection.

Целью изобретения является повышение эффективности защиты стабилизатора путем увеличения стабильности порога срабатывания защиты и уменьшения влияния защиты на стабильность выходного напряжения. ·The aim of the invention is to increase the protection efficiency of the stabilizer by increasing the stability of the protection threshold and reducing the influence of protection on the stability of the output voltage. ·

Поставленная цель достигается тем, что в стабилизатор напряжения с защитой от перегрузок введены транзистор защиты и резистор, причем упомянутые крайние выводы ограничительного резистора и другого из резисторов де лителя через коллекторно-эмиттерный и базо-эмиттерный переходы транзистора защиты соответственно подключены датчике 8 тока), а.ток базы транзистора 7 уменьшается настолько, насколько увеличивается ток резистора 9 (поскольку U_6blx, а следовательно, 5 и ток делителя выходного напряжения еще остаются практически неизменными) При достижении током нагрузки (при его увеличении в процессе перегрузки) пороговой величины 1 η транзистор 7 пек выходному выводу, а датчик тока ю включен между выходным выводом и коллектором регулирующего транзистора, который через введенный резистор подключен к базе транзистора защиты.This goal is achieved by the fact that a protection transistor and a resistor are introduced into the voltage stabilizer with overload protection, and the mentioned extreme terminals of the limiting resistor and the other of the divider resistors are connected to the current sensor 8 respectively through the collector-emitter and base-emitter junctions), and the base current of transistor 7 decreases as much as the current of resistor 9 increases (since U _6blx , and therefore 5 and the current of the output voltage divider, remain almost unchanged) when the load current (when it increases during the overload) reaches a threshold value of 1 η transistor 7 pitch to the output terminal, and the current sensor is connected between the output terminal and the collector of the control transistor, which is connected to the base of the protection transistor through the input resistor.

На чертеже представлена принципи- is альная электрическая схема устройства.The drawing shows a schematic electrical diagram of the device.

Стабилизатор содержит регулирующий транзистор 1, подключенный эмиттером к входному выводу, базой к выходу усилителя 2 обратной связи, входы которого соединены с выходами источни- _;ка опорного напряжения на стабилитроне 3 и ограничительном резисторе 4 и делителя выходного напряжения на 25 двух резисторах 5 и 6, причем крайние выводы стабилитрона 3 и резистора 6 подключены к общей шине, крайний вывод резистора 4 через коллекторноэмиттерный, а крайний вывод резистора ₃₀5 через базо-дмиттерный переход тран-. зистора 7 защиты подключены к выходному выводу. Датчик 8 тока включен в выходную шину между коллектором транзистора 1 и выходным выводом, а введенный резистор 9 включен между коллектором транзистора 1 и базой транзистора 7 ·The stabilizer contains a regulating transistor 1 connected by an emitter to an input terminal, the base to the output of a feedback amplifier 2, the inputs of which are connected to the outputs of the source _; ka of the reference voltage at the zener diode 3 and the limiting resistor 4 and the output voltage divider for 25 two resistors 5 and 6, the extreme terminals of the zener diode 3 and resistor 6 connected to a common bus, the extreme terminal of resistor 4 through the collector-emitter, and the extreme terminal of resistor ₃₀ 5 through the base -transmitter transition. the protection resistor 7 is connected to the output terminal. The current sensor 8 is included in the output bus between the collector of the transistor 1 and the output terminal, and the introduced resistor 9 is connected between the collector of the transistor 1 and the base of the transistor 7 ·

Стабилизатор работает следующим образом.The stabilizer works as follows.

В режиме нормальной работы транзистор 7 открыт и насыщен за счет протекания через его входную цепь части тока делителя 5, 6 выходного напряжения. Другая часть этого тока протекает через резистор 9- Насыщенное состояние транзистора 7 при нормальном режиме работы стабилизатора обеспечивается выбором величин сопротивления резистора 9 и датчика 8 тока. При возникновении перегрузки на выходе ⁵⁰стабилизатора (при уменьшении сопротивления нагрузки 10) увеличивается ток нагрузки, падение напряжения на датчике 8 тока и ток, протекающий черёз резистор 9 (поскольку величина напряжения на этом резисторе равна сумме падений напряжения на переходе база - эмиттер транзистора 7 и реходит из насыщенного состояния в активный режим и начинает запираться, что приводит к уменьшению его коллекторного тока (тока через опорный стабилитрон 4) и далее - к прекращению роста входного и выходного токов усилителя 2 обратной связи и тока нагрузки стабилизатора (при этом ток нагрузки ограничивается 'практически на уровне 1п). При дальнейшем уменьшении сопротивления на-’ грузки 10 выходное напряжение начинает уменьшаться, вызывая уменьшение тока делителя 5,6, еще более глубокое запирание транзистора 7» уменьше*· ние токов усилителя обратной связи и тока нагрузки стабилизатора. Уменьшение тока нагрузки вызывает пропорциональное уменьшение выходного напряжения, тока делителя 5» 6, дальнейшее запирание транзистора 7. Это! процесс развивается регенеративнб и приводит к необратимому запиранию стабилизатора. Для восстановления нормального режима работы стабилизатора после устранения (или самопроизвольного исчезновения) перегрузки может быть использован любой из известных способов полуимпульсного запуска стабилизаторов.In normal operation, the transistor 7 is open and saturated due to the flow through its input circuit of the current part of the current divider 5, 6 of the output voltage. Another part of this current flows through the resistor 9. The saturated state of the transistor 7 during normal operation of the stabilizer is provided by the choice of resistance values of the resistor 9 and the current sensor 8. When an overload occurs at the output of the stabilizer ⁵⁰ (with a decrease in the load resistance 10), the load current increases, the voltage drop across the current sensor 8 and the current flowing through the resistor 9 (since the voltage across this resistor is equal to the sum of the voltage drops at the base - emitter junction of the transistor 7 and goes from the saturated state to the active mode and starts to lock, which leads to a decrease in its collector current (current through the reference zener diode 4) and then to the termination of the growth of the input and output currents of the amplifier 2 feedback and stabilizer load current (in this case, the load current is limited to 'practically 1p.) With a further decrease in load resistance 10, the output voltage begins to decrease, causing a decrease in the current of the divider 5.6, an even deeper blocking of the 7 ”transistor decreases * · Feedback amplifier current and stabilizer load current Decrease in the load current causes a proportional decrease in the output voltage, divider current 5 ”6, further locking of the transistor 7. This! the process develops regenerative and leads to irreversible locking of the stabilizer. To restore the normal operation of the stabilizer after the elimination (or spontaneous disappearance) of the overload, any of the known methods for the half-pulse start of stabilizers can be used.

Поскольку при нормальном режиме . работы стабилизатора (когда ток нагрузки меньше 1п) транзистор 7 находится в режиме насыщения, изменения тока нагрузки практически не влияют на величины межэлектродных напряжений этого транзистора, а следовательно, и на величины опорного напряжения стабилитрона 4 и выходного напряжения. Это позволяет обеспечить высокую чувствительность защиты от перегрузок и стабильность выходного напряжения, т. el существенно ослабить дестабилизирующее влияние защиты от перегрузок на стабильность и_ВЬ|Х. Изменение режима работы стабилизатора (изменение питающего напряжения и_пиТ<. тока нагрузки, а также разброс коэффициентов усиления по току транзисторов) не оказываетBecause in normal mode. the operation of the stabilizer (when the load current is less than 1p), the transistor 7 is in saturation mode, changes in the load current practically do not affect the values of the interelectrode voltages of this transistor, and consequently, the values of the reference voltage of the Zener diode 4 and the output voltage. This makes it possible to ensure high sensitivity of protection against overloads and stability of the output voltage, i.e., el significantly weaken the destabilizing effect of protection against overloads on stability and _{B | X.} A change in the operating mode of the stabilizer (a change in the supply voltage and _piT <. _{Of the} load current, as well as the spread of the gain of the current of the transistors) does not

964607 6 влияния на тепловой и электрический ' режимы транзистора 7 (поскольку последний нормально находится в режиме насыщения и включен в цепь питания опорного стабилитрона, ток ко- $ торой не зависит от указанных факторов) , что повышает стабильность порога срабатывания защиты от перегрузок (в известном устройстве сигнал· перегрузки подается во входную цепь 10 транзистора оконечного каскада усилителя обратной связи, тепловой и электрический режим которого зависят от режима стабилизатора).964607 6 effects on the thermal and electric modes of transistor 7 (since the latter is normally in saturation mode and is included in the power supply of the reference zener diode, the current of which does not depend on these factors), which increases the stability of the overload protection threshold (in the known device · overload signal is fed into the input circuit 10 of the transistor of the terminal stage of the feedback amplifier, the thermal and electric mode of which depend on the stabilizer mode).

Изъятие датчика тока из общей ши- 15 ны и включение его в одну силовую шину с регулирующим транзистором также способствует повышению эффективности защиты предлагаемого стабилизатора, по сравнению с известным го устройством путем снятия ограничения на характер построения системы электропитания .The removal of the current sensor from the common bus and its inclusion in the same power bus with a regulating transistor also improves the protection efficiency of the proposed stabilizer, in comparison with the known device by removing the restriction on the nature of the construction of the power supply system.

²⁵²⁵

Claims

, ... The invention relates to stabilized power sources. A voltage regulator is known, which contains a regulating transistor connected by an emitter to an input terminal, and a collector to an output one, a feedback amplifier, an output voltage divider, a source of reference voltage, and a stabilizer protection unit 1. Its disadvantage is significant in the complexity of the overload protection assembly. The closest to the invention in its technical essence is a voltage stabilizer with overload protection, containing a regulating transistor, the emitter of which is connected to the input, and the collector is connected to the output terminals, the feedback coupler, the output connected to the base of the regulating transistor, the source of the reference voltage on the Zener diode and pg-: the limiting resistor and the output voltage divider HCI are two resistors, the average outputs of which are connected to the inputs of the feedback amplifier, the extreme outputs of the Zener diode and one of the divider resistors is connected to the common bus, and the extreme terminals of the limiting resistor and the other of the divider resistors are connected to the output of the stabilizer, a current sensor included in one of the power rails C2. A disadvantage of the known device is the low protection efficiency, which implies a large influence of protection on the stability of the output voltage, and a considerable instability of the protection response threshold. The aim of the invention is to increase the effectiveness of the protection of the stabilizer by increasing the stability of the -. The horns trigger the protection and reduce the effect of protection on the stability of the output voltage. 3, 96 The goal is achieved by introducing a protection transistor and a resistor into the voltage regulator with overload protection, and the aforementioned extreme conclusions of the limiting resistor and another divider are through the collector-emitter and base-emitter transitions of the protection transistor, respectively, connected to output terminal, and a current sensor is connected between the output terminal and the collector of the regulating transistor, which the inserted resistor is connected to the base of the protection transistor. The drawing shows a schematic electrical circuit device. The stabilizer contains a regulating transistor 1 connected by an emitter to an input terminal, a base to the output of a feedback amplifier 2, whose inputs are connected to the outputs of a reference voltage source on a stabilizer 3 and a limiting resistor 4 and an output voltage divider for two resistors 5 and 6 the extreme leads of the Zener diode 3 and the resistor b are connected to the common bus, the extreme lead of the resistor k through the collector emitter, and the extreme lead of the resistor 5 through the base-dmitter nepexcaq of the protection transistor 7 are connected to the output pin . The current sensor 8 is connected to the output bus between the collector of the transistor 1 and the output terminal, and the input resistor 9 is connected between the collector of the transistor 1 and the base of the resistance 7. The stabilizer operates as follows. In normal operation, the transistor 7 is open and saturated by flowing a portion of the divider 5, 6 of the output voltage through its input circuit. Another part of this current flows through the resistor 9. The saturation state of the transistor 7 during the normal operation of the stabilizer is ensured by selecting the values of the resistance of the resistor 9 and the current sensor 8. When an overload occurs at the stabilizer output (when the load resistance 10 decreases), the load current increases, the voltage drop across the current sensor 8 and the current flowing through the resistor 9 {since the voltage across this resistor is equal to the sum of the base-to-emitter voltage drops 7 and current sensor 8), and the base current of the transistor 7 decreases as much as the current of the resistor 9 increases (since (g, J, and hence the current of the output voltage divider still remain almost unchanged). the load current (when it increases during the overload) of the threshold value 1p, the transistor 7 goes from the saturated state to the active mode and begins to lock, which leads to a decrease in its collector current (current through the Zener diode) and then to stop the growth of the input and output feedback amplifier and stabilizer load current (the load current is limited to almost In). With a further decrease in load resistance 10, the output voltage begins to decrease, causing a decrease in The current of the divider is 5.6, and deeper locking of the transistor 7 is a decrease in the currents of the feedback amplifier and the stabilizer load current. A decrease in the load current causes a proportional decrease in the output voltage, the current of the divider 5, 6, further locking of the transistor 7 Stot process develops regeneratively and leads to irreversible locking of the stabilizer. To restore the normal operation of the stabilizer after the elimination (or spontaneous disappearance) of the overload, any of the known methods of semi-pulsed triggering of the stabilizers can be used. Since under normal mode. operation of the stabilizer (when the load current is less than In,) the transistor 7 is in saturation mode, changes in the load current have almost no effect on the values of the interelectrode voltages of this transistor, and hence on the values of the reference voltage of Zener diode 4 and output voltage. This allows a high sensitivity of the overload protection and stability of the output voltage, e. To significantly weaken the destabilizing effect of overload protection on the stability of the regulator (changing the supply voltage of the transistors) does not affect the thermal and electrical modes of the transistor 7 (since the latter is normally in saturation mode and is connected to the power supply of the reference Zener diode, the current of which is not depends on these factors), which increases the stability of the overload protection threshold (in a known device, an overload signal is supplied to the input circuit. The transistor of the terminal stage of the feedback amplifier, the thermal and electrical conditions of which depend on the stabilizer mode). Removing the current sensor from the common bus and plugging it into a single power bus with a regulating transistor also contributes to increasing the protection efficiency of the proposed stabilizer, compared to the known device by removing the limitations on the nature of the power supply system. Claims An overvoltage overvoltage voltage regulator comprising regulating a transistor, the emitter of which is connected to the input, and the collector is connected to the output terminals, a feedback amplifier, an output connected to the base of the regulating transistor, a source of reference voltage on the zener diode and a limiting a resistor, and a divider of the output voltage on two resisgs,, tori, whose average terminals are connected; The extreme terminals of the Zener diode and one of the divider resistors are connected to the common bus, and the extreme terminals of the limiting resistor and the other of the divider resistors are connected to the output terminal of the stabilizer, current sensor, VKJ: light, to one of the power buses , characterized in that, in order to increase the efficiency of protection, a transistor is introduced into the black for. boards and a resistor, with the mentioned extreme limiting resistor and the other of the resistors divider through the collector-emitter and base-emitter transitions of the protection transistor, respectively, are connected to the output terminal, and the current sensor is connected between the output terminal and the collector of the control transistor, which through the inserted resistor connected to the base of the transistor protection. Sources of information taken into account in the examination 1. US patent number, class. 323-9, 1961.

2. Authors certificate of the USSR .7 517886, cl. G 05 F 1/58, 1976.