SU1626363A1 - Electronic on/off device - Google Patents

Abstract

The invention can be used in key high and medium power sources. The purpose of the invention is to increase reliability and efficiency. The contactless key device contains an input transformer 2 connected to the output of the clock generator 1, diode-resistor summers 3 and 4, a push-pull key amplifier 5, an output transformer 6, a rectifier 7, transistor switches 8, 9 and locks 10, 11 levels. Providing the quasi-pinch mode of the transistors of the key amplifier 6 makes it possible to increase the efficiency and reliability of the device. 1 il.

Description

The invention relates to a pulse technique and electronics and is intended for use in key power sources of large and medium power.

The aim of the invention is to increase reliability and efficiency.

The drawing shows a circuit diagram of the proposed device.

The device contains a clock generator 1, an input transformer 2, diode-resistive combiners 3 and 4, a push-pull key amplifier 5, an output transformer 6 with a rectifier 7, transistor switches 8 and 9, and latches 10 and 11 of the level. Moreover, the push-pull terminal stage can be performed both by the usual push-pull circuit and by the half-bridge circuit.

The latches 10 and 11 of the level are designed to ensure equal voltages at the bases of transistor switches 8 and 9 when they are open and the voltages at the collectors of transistors 12 and 13, thereby achieving a quasi-saturated transistor mode of the push-pull key amplifier 5. The latches 10 and 11 of the level can be made on the diode -resistive circuits.

Transistor switches 8 and 9 are needed to close the base current of the transistors 12 and 13 of the push-pull key amplifier. Moreover, the transistor switches 8 and 9 ensure that the input current flows through the base circuit of the transistors 12 and 13 (through the base-emitter junction of the transistors 14 and 15, and from the additional windings of the transformer 6).

Transistor switches 8 and 9 operate in two modes: in linear mode when the transistors 12 and 13 are in quasi-saturation mode; in key mode when the transistors 12 and 13 are in linear mode for load resistance of a lower nominal value.

The diode-resistive combiners 3 and 4 are designed to eliminate the transistor-transistor through-currents in the push-pull key amplifier 5, which is achieved by supplying a negative voltage to the base circuit of one of the transistors, for example 13, until the other transistor 12 is closed.

The device operates as follows.

The clock generator generates a pulsed voltage of the meander type, which through the input transformer 2 enters the inputs of the latches 10 and 11 of the level. The out-of-phase output voltage of the secondary windings of the input transformer 2 provides the in-phase switching on and off of the transistors 14 and 15, through the base-emitter transitions of which the input current enters the base circuits of the transistors 12 and 13 of the push-pull key amplifier 5. However, until the previously opened transistor 13 of the key amplifier is locked on the basis of another transistor 12 is provided with a negative voltage supplied through the diode of the corresponding diode-resistive adder with an additional transformer winding RA 6. Thus, the elimination of through currents of the transistor - transistor, which can be caused by the presence of a delay in turning off the transistors.

When the transistor of the opposite arm, for example 13, of the push-pull key amplifier is turned off, the output voltage of the key amplifier 5 drops to zero, which leads to the inclusion of the transistor 12 by the input current and, accordingly, to an increase in voltage on the additional winding connected to the output of the transistor switch 8, which is in the open state . The latter leads to an increase in the base current of the transistor 12 due to the current closed through the additional winding, the resistor and transistor 14. As a result, the transistor 12 goes into the open state, characterized by a small residual voltage. In this case, a part of the input current is closed through the diode of the level lock 10, which ensures the approximate potential equality on the basis of the transistor 14 and the collector of the transistor 12, which is associated with the transition of the transistor 13 to the linear mode, in which the current closes through the resistor, the value of which does not exceed the value required to maintain the base current of the transistor 12 at a level that provides quasi-saturation.

In this mode, the residual voltage at the transistor 12 is small, and at the same time, the charge of minority carriers in the base of the transistor is negligible, which ensures its quick shutdown when the output voltage of the clock generator 1 changes. In the proposed device, the opening of the transistors regardless of the output current is carried out by the maximum base current, which due to the increase in losses in the input circuit of the transistors of the key amplifier and with a significant inertia of turning them off.

Thus, providing a regime of quasi-saturation of the transistors of the key amplifier 5 allows to increase its energy characteristics.

When the output voltage of the clock generator changes, the voltage at the input of the transistor switch 8 becomes negative, which leads to its locking and, accordingly, to the locking of the transistor 12 and the inclusion of the transistor 13 of the key amplifier.

With a decrease in load resistance, transistors 12 and 13 go into a linear mode of operation, characterized by an increase in residual voltage in their open state. This leads to a decrease in voltage on the additional windings, which is associated with a decrease in the base current.

Thus, when the key amplifier is overloaded, there is a sharp decrease in the output current, which can significantly reduce the power loss on the semiconductor devices of the terminal stage and increase the reliability of the proposed device.

Claims (1)

Claim A non-contact key device containing a push-pull key amplifier made on two transistors, the emitters of which are connected to the first bus of the power source, collectors with the corresponding extreme terminals of the primary winding of the output transformer, the middle terminal of which is connected to the second bus of the power source, the base to the outputs of the corresponding diode -resistive adders, the first conclusions of the two out-of-phase additional windings of the output transformer are connected to the first bus of the power source, the second conclusions are additional windings of the output transformer are connected to the first inputs of the corresponding diode-resistive adders, the primary winding is connected to the outputs of the clock generator, the secondary winding of the output transformer * · of the torus is connected to the output buses, which is introduced in order to increase reliability and efficiency two transistor switches and two level locks, the first inputs of the level locks connected to the second terminals of the corresponding secondary windings of the input transformer, the second inputs to the collectors respectively vuyuschih transistor push-pull amplifier is a key, outputs - with transistor switches control inputs, first terminals of which are connected to the second terminal of the antiphase additional windings of the output transformer and the second terminal - to the second inputs of the respective diode-resistor adders. Compiled by L. Bagyan Editor A. Motyl Tehred M. Morgenthal Corrector N. Revskaya Order 284 Circulation 458 Subscription VNI14PI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.