SU1550615A1 - Transistor switch - Google Patents

Abstract

The invention relates to a pulse technique, mainly to a pulse power amplifier, and can be used in energy converters, secondary power sources. The purpose of the invention is to improve the reliability of operation - by introducing a single vibrator 17, key elements 12, 14, 8, and diodes 6, 7, 10, 11. The key also contains a switching transistor 1, a controlled current source 4, a charging 15 and a bit 16 elements , storage capacitor 13, power busbars 5, 9, common bus 3, output bus 2, control bus 18. Due to the introduction of new elements, the charging and discharging time of the capacitor 13 does not depend on the duty cycle of the transistor 1, which ensures the stability of the average voltage on the capacitor 13 and the resorption time of minority carriers in transistor 1. 3 Il.

Description

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The invention relates to a pulse technique, mainly to a pulse power amplifier, and can be used in an electric power conversion device, secondary power sources, automated electric drive systems, and the like.

The purpose of the invention is to increase the reliability of work.

Figure 1 shows the structural diagram of the proposed transistor switch; figure 2 (aD) - time diagrams of his work; FIG. 3 is a schematic diagram of one of the possible variants of the proposed device.

The transistor switch contains a switching-transistor 1, the collector of which is connected to the output bus 2, and the emitter - to the common bus 3. In the unlocking circuit of the switching transistor 1, a controlled current source 4 is connected, also connected to the first power supply bus 5. The base of the switching transistor 1 and the control output of the current source 5 through diodes 6 and 7 respectively and the first key element 8 are connected to the second power supply bus 9, and through respectively the diodes 10 and 11 and the second key element 12 to the second output of the storage capacitor 13, which, via the third key element 14, is connected to the bus 9. The first output of the storage capacitor 13 through the charge 15 and the discharge 16 elements is connected respectively to the buses 5 and 3. The control outputs of the elements 15 and 16, as well as the key elements 12 and 14 are connected to you the movement of the one-vibration 17, the input of which, as well as the control output of the key element 8, are connected to the control bus 18.

The device works as follows.

At time t, the bus 18 is given a release signal (Fig. 2a). The output of the one-shot 17 when

this does not change and remains at a high level (Fig. 26). In this case, the charging element 15 and the key element 14 are open, and the discharge element 16 and the key element 12 are closed. Thus, the storage capacitor 13 is connected to the positive 5 and negative 9 power lines respectively and is charged (Fig. 2c, d). Under

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the action of the input signal closes the key element 8 and removes the lock signal from the control terminal of the current source 4. The current source 4 is opened, allowing the unlocking current to flow into the base of the switching transistor 1, whose base-emitter voltage becomes positive (FIG. 2e). The diode 7 prevents the control output of the current source 4 from shorting to the base of the switching transistor 1.

At the time t, the unlocking signal is removed from the bus 18 (Fig. 2a), the negative vibrator 17 is triggered by the negative differential and the key element 8 opens. The output signal of the one vibrator 17 switches to a low level. The charging element 15 and the key element 14 are closed, and the discharge element 16 and the key element 12 are opened. Thus, the storage capacitor 13 is disconnected from the power lines and through the key element 12, the diode 11 and the discharge element 16 is connected between the base and the emitter of the switching transistor 1, the base-emitter voltage of which becomes negative and equal in absolute value to the sum of positive and negative voltages. on tires 5 and 9 of power (fig.2d).

A control output of the current source 4 through the diode 10 is given a latching signal; the current source 4 closes and the current flow to the base of the switching transistor 1 stops.

In this case, the forced locking of the switching transistor 1 occurs and the discharge current flows through the storage capacitor 13 (fig.2b), the voltage across it decreases (fig.2g)

The key element 12 and the bit element 16 will remain open throughout the relaxation time of the one-shot 17, which is chosen to ensure reliable locking of the switching transistor 1. The diode 11 prevents the control output of the current source 4 from shorting to the base of the switching transistor 1, At time The t3 signal at the output of the single-vibrator 17 switches to a high level (Fig. 26), the key element 12 and the discharge element 16 are

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are covered, and key element 14 and charging element 15 are opened. Thus, the storage capacitor 13 is disconnected from the base and the emitter of the switching transistor 1, thereby terminating the forced lock-up process, and connected again to the supply buses 5 and 9, thus forming its charge circuit (Fig. 2c, d).

Since the signal on bus 18 has not changed (Fig. 2a), key element 8 continues to remain open. Thus, the control terminal of the current source 4 and the base of the switching transistor 1 through diodes 6 and 7 respectively and the open key element 8 are connected to the negative bus 9, thereby ensuring the active locking of the switching transistor 1 before the next unlocking signal arrives (FIG. .2d) Diodes 7 and 10 prevent each other from affecting each other by holding (key element 8) and forming (key element 12) chains. At time t, the unlocking signal is again applied to the bus 18, and the processes in the device are repeated.

In the description and in fig. 2a, b, the levels of control signals are shown conditionally and without reference to the particular circuitry of the elements used. Only their differences and mutual position in time are of fundamental importance.

Fig. 3 is a schematic diagram of one of the possible variants of the proposed device. The key elements and the charge and discharge elements are implemented on bipolar transistors of various types of conductivity.

Thus, due to the fact that the time interval C2 - Ce (Fig. 2) is determined only by the relaxation time of the introduced one-shot 17, the charging and discharging time of the storage capacitor 13 does not depend on the ratio of open and closed times (work cycle) com

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mutated transistor 1. This makes the stability of the average value of the voltage across the storage capacitor 13 and, accordingly, the dissipation and decay periods of the switching transistor.

Due to the introduction of the key element 8 into the transistor switch, in the absence of the unlocking signal on the bus 18, the switching transistor 1 is kept in the active latching mode, which significantly increases the reliability of the device.

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Formula of invention

A transistor switch containing a switching transistor, a controlled current source, a storage capacitor, a charge and discharge controlled elements, a switching transistor collector connected to the output bus, an emitter with a common bus, and a base through a controlled current source with the first power bus The first output of the storage capacitor is connected via the charging element to the first power supply bus, and through the discharge element to the common bus, characterized in that, in order to increase the reliability of operation, a single vibrator is introduced, three key elements and four diodes, the base of the switching transistor and the control output of the controlled current source through the corresponding first and second diodes and the first key element are connected to the second power bus, and through the corresponding third and fourth diodes and the second key element to the second output of the storage capacitor through the third key element is connected to the second power bus, the control pins of the second and third key elements, which operate in the counterphase, as well as the control pins of the charge and AZR-stand elements are connected to the output of the monostable having an input coupled to the control bus, which is connected to the control terminal of the first key member.

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Claims (1)

A transistor switch containing a switching transistor, a controlled current source, a storage capacitor, a charging and discharge controlled elements, a commutator of the switching transistor is connected to the output bus, the emitter is connected to the common bus, and the base through the controlled current source is connected to the first power bus, the first output of the storage capacitor through the charging element it is connected to the first power bus, and through the discharge element to the common bus, characterized in that, in order to increase the reliability of operation, a single vibrator, three key elements and four diodes, the base of the switching transistor and the control terminal of the controlled current source through the corresponding first and second diodes and the first key element are connected to the second power bus, and through the corresponding third and fourth diodes and the second key element to the second terminal of the storage capacitor, which the third key element is connected to the second power bus, the control terminals of the second and third key elements that operate in antiphase, as well as the control terminals of the charging and discharge o elements are connected to the output of a single-shot, the input of which is connected to the control bus, which is connected to the control output of the first key element.