SU898596A1

SU898596A1 - Single-shot multivibrator

Info

Publication number: SU898596A1
Application number: SU742013984A
Authority: SU
Inventors: Владимир Ефремович Светличный; Владимир Николаевич Дыченко
Original assignee: Предприятие П/Я А-7160
Priority date: 1974-04-04
Filing date: 1974-04-04
Publication date: 1982-01-15

Description

Изобретение относится к импульсной технике и может быть использовано в устройствах для формирования временных задержек и импульсов различной длительности.The invention relates to a pulse technique and can be used in devices for generating time delays and pulses of various durations.

Известен одновибратор с коллекторно-базовыми связями на двух транзисторах, в котором времязадающим элементом является конденсатор, включенный между коллектором нормально закрытого и базой'нормально открытого транзисторовA single vibrator with collector-base coupling on two transistors is known, in which the timing element is a capacitor connected between a normally closed collector and a base of normally open transistors

Однако этот одновибратор не позволяет использовать кремниевые транзисторы на полное коллекторное напряжение, так как у них сравнительно невелико допустимое обратное напряжение перехода эмитуер-базауHowever, this single-shot does not allow the use of silicon transistors for full collector voltage, since they have a relatively small allowable reverse voltage of the transition emitter-base

Наиболее близким к предлагаемому является одновибратор на кремниевых п-р-п транзисторах, содержащий конденсатор в цепи обратной связи коллектора нормально закрытого с ба• 2 зой нормально открытого транзистоР^а[²]·The closest to the proposed one-shot is on Si p-n-p transistor having a capacitor in the feedback circuit with a normally closed reservoir • Ba 2 Zoe normally open transistors ^and ^[2] ·

Однако в таком одновибраторе нет защиты перехода эмиттер-база закрытого транзистора от пробоя обрат5 ным напряжением. Включение параллельно его переходу эмиттер-база защитного устройства приводит к значительному снижению длительности формируемого импульса из-за уменьшения 10 постоянной времени цепи разряда времязадающего конденсатора.However, in such a single-shot, there is no protection for the emitter-base transition of the closed transistor from breakdown by reverse voltage. The inclusion of a protective device parallel to its transition from the emitter-base leads to a significant decrease in the duration of the generated pulse due to a decrease in the 10 time constant of the discharge circuit of the timing capacitor.

Цель изобретения - защита перехода эмиттер-база закрытого транзистора от пробоя обратным напряжением 15 и увеличение длительности формируемого импульса.The purpose of the invention is the protection of the emitter-base transition of a closed transistor against breakdown by reverse voltage 15 and an increase in the duration of the generated pulse.

Поставленная цель достигается тем, что в одновибраторе на кремниевых п-р-п транзисторах, содержа²⁰ щем конденсатор в цепи связи коллектора нормально закрытого транзистора с базой нормально открытого транзистора, между базами транзисто з 898596 ров введен стабилитрон, напряжение стабилизации которого меньше допустимого обратного напряжения перехода эмиттер-база нормально открытого транзистора, подключенный катодом к ₅базе нормально закрытого транзистора.The goal is achieved in that the monostable multivibrator at the silicon n-p-n transistors, containing ²⁰ present capacitor in circuit communication reservoir normally closed transistor to the base of a normally open transistor between bases Transistor of 898,596 moat introduced zener voltage stabilization is smaller than the permissible reverse voltage the emitter-base transition of a normally open transistor connected by a cathode to the _5th base of a normally closed transistor.

На чертеже приведена принципиальная электрическая схема одновибратора. 10The drawing shows a circuit diagram of a single vibrator. 10

Одновибратор содержит два кремниевых п-р-п транзистора 1 и 2, стабилитрон 3, включенный между базами транзисторов, резисторы 4-6 в коллекторных и базовых цепях транзисто- 15 ров, конденсатор 7, включенный между коллектором транзистора 1 и базой транзистора 2, и диод 8 в базовой цепи транзистора 1.A single-shot contains two silicon pnp transistors 1 and 2, a zener diode 3 connected between the bases of transistors, resistors 4-6 in the collector and base circuits of transistors 15, a capacitor 7 connected between the collector of transistor 1 and the base of transistor 2, and diode 8 in the base circuit of transistor 1.

Одновибратор работает следующим J0 образом.The single-shot works as follows J0.

В исходном состоянии транзистор закрыт, транзистор 2 открыт, а конденсатор 7 заряжен практически до напряжения источника питания + Е. 25In the initial state, the transistor is closed, the transistor 2 is open, and the capacitor 7 is charged almost to the voltage of the power supply + E. 25

При подаче через диод 8 положи ние на его коллекторе уменьшаетая, а напряжение на базе.транзистора 2 остается постоянным. При дальнейшем разряде конденсатора 7 стабилитрон 3 выключается и отрицательное напряжение на базе транзистора 2 уменьшается по экспоненциальному закону в соответствии с напряжением на конденсаторе 7 до возвращения схемы в исходное состояние.When applied through diode 8, the position on its collector decreases, and the voltage at the base of transistor 2 remains constant. With a further discharge of the capacitor 7, the zener diode 3 turns off and the negative voltage at the base of the transistor 2 decreases exponentially in accordance with the voltage on the capacitor 7 until the circuit returns to its original state.

Таким образом, предложенный одновибратор дает возможность формирования импульсов с амплитудой, практик чески равной допустимому коллекторному напряжению кремниевого транзистора, при полностью исключенной возможности пробоя перехода эмиттер-база нормально открытого транзистора. Кроме того, одновибратор позволяет повысить длительность формируемого импульса.Thus, the proposed one-shot makes it possible to generate pulses with an amplitude almost equal to the permissible collector voltage of the silicon transistor, with the possibility of breakdown of the emitter-base transition of the normally open transistor being completely excluded. In addition, a single-shot allows you to increase the duration of the generated pulse.

Claims

(54) ONE SELECTOR The invention relates to a pulsed technique and can be used in devices for generating time delays and pulses of various durations. The one-shot with collector-6-phase connections on two transistors is known, in which time the driving element is a capacitor connected between a normally closed collector and a base-normal open transistor flj However, this one-shot does not allow to use silicon transistors for a full collector voltage because they have a relatively small permissible reverse voltage transition emitter-base. The closest to the proposed is a single vibrator on silicon npp transistors containing op in the feedback circuit collector normally closed with base normally open tranzistoOdnako in that no protection odnonibratore transition gated transistor of the emitter-base reverse breakdown voltage. Switching the emitter-base of the protective device parallel to its transition leads to a significant reduction in the duration of the generated pulse due to a decrease in the time constant of the discharge circuit, the time of the driving capacitor. The purpose of the invention is to protect the emitter-base transition of a closed transistor against breakdown by reverse voltage and to increase the duration of the generated pulse. This goal is achieved by the fact that in a single vibrator on silicon npp transistors containing a capacitor in the collector connection circuit of a normally closed transistor with a base of a normally open transistor, there is a transistor 3 between the bases. A zener diode is introduced, the stabilization voltage of which is less than the permissible reverse voltage of the emitter-base transition of a normally open transistor connected by a cathode to the base of a normally closed transistor. The drawing shows the electrical circuit of a single vibrator. The single-oscillator contains two silicon npp transistors 1 and 2, a zener diode 3 connected between the bases of the transistors, resistors 4-6 in the collector and base circuits of the transistors, a capacitor 7 connected between the collector of transistor 1 and the base of transistor 2, and diode 8 in the base circuit of the transistor 1. The single-oscillator operates as follows. In the initial state, the transistor 1 is closed, the transistor 2 is open, and the capacitor 7 is charged almost to the voltage of the power source + E. When a positive triggering pulse is applied through the diode 8, the transistor 1 opens, the voltage on its collector drops, and The effect on the base of transistor 2 due to the charge accumulated by capacitor 7 becomes negative. The voltage across the collector of transistor 2 rises through a divider., Consisting of resistors 5 and 6, keeps transistor 1 in the open state. When the negative voltage at the base of transistor 2 reaches the level of the breakdown of Zener diode 3, the latter starts to pass a current that reduces the base current of transistor 1, which leads to an increase in the voltage on its collector, a dynamic equilibrium is established at which the negative voltage at the base of transistor 2 is determined voltage difference across the capacitor 7 and the collector of transistor 1 and practically does not exceed the level of operation of Zener diode 3. As the capacitor 7 discharges, the base current of transistor 1 increases, the voltage across it The collector is reduced, and the voltage on the base of the transistor 2 remains constant. Upon further discharge of the capacitor 7, the zener diode 3 is turned off and the negative voltage at the base of the transistor 2 decreases exponentially according to the voltage on the capacitor 7 until the circuit returns to its original state. Thus, the proposed one-shot makes it possible to form pulses of amplitude, practically equal to the permissible collector voltage of a silicon transistor, with the possibility of an emitter-base transition of a normally open transistor completely excluded. In addition, the Single Vibrator makes it possible to increase the duration of the generated pulse. Claims of the invention A single-oscillator on silicon pnp transistors containing a capacitor in a collector connection circuit of a normally closed transistor with a base of a normally open transistor, characterized in that, in order to protect the emitter-base transition of a closed transistor against breakdown voltage and increase in duration generated pulse, a zener diode is inserted between the bases of the transistors, the stabilization voltage of which is less than the allowable reverse voltage of the emitter base of a normally open transistor, ny cathode to the base of transistor normally closed. Sources of information taken into account in the examination 1. Ya. Vudinsky. Transistor switching circuits. M., Svy, 1965, p. 376, fig. 280.

2. The patent of Germany No. 1275111, cl. 21 a 36/02 (prototype).

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