SU1610571A1 - Semi-bridge transistor inverter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power supply and automation systems. The purpose of the invention is to increase reliability by reducing dynamic losses when switching transistors. Half-bridge inverter contains two transistors 1 and 2 of different conductivity type. Transistors 1 and 2 are controlled by a control pulse generator 19 through a control transformer 15. The base current of transistors 1 and 2 includes the first resistor 12, shunted by the first diodes 10, 11. Due to this, during the dissolution of excess carriers in one of the locking transistors 1 (2), the voltage drop across the resistor 12 prevents the other transistor 2 (1) from unlocking. 1 il.

Description

This invention relates to electrical engineering and can be used in secondary power supply and automation systems.

The purpose of the invention is to increase reliability by reducing dynamic losses when switching transistors.

The drawing schematically shows a half-bridge transistor inverter.

The inverter contains transistors 1 and 2 of different types of conductivity and two capacitors 3 and 4, forming a half-bridge circuit. The output diagonal includes a power transformer 5 containing the primary 6 and the secondary 7 windings. The second diodes 8 and 9 form the return circuit of the power inverter of the load current to the power source. Between the emitters of the transistors 1, 2, the first diodes 10, 11 are connected in series in the forward direction, which shunt the first resistor connected between the emitters of the transistors, 12. The bases of the transistors 1, 2 are connected to the same ends of the secondary windings 13, 14 of the control transformer, formatter 15 via the second resistors 16 and 17. A generator of control rectangular pulses is connected to the primary winding 18 of the transformer 15.

The inverter works as follows.

When a constant voltage supply is applied, the capacitors 3 and 4 are charged and the voltage distribution is |

on the reverse resistance of the diodes 8-11 and the collector-emitter junction of transistors 1, 2. With the equal resistance of the diodes 8-11 and capacitors 3, 4 capacitances, both ends of the primary winding 6 of the power transformer 5 are set to the same voltage,

equal to half the input voltage. The voltage applied to the collector-emitter junction of the transistors 1, 2 causes a current to create a voltage drop across the forward resistance of the diodes 10, 11 and the resistor 12, blocking the transistors 1 and .2.

Upon receipt of the unlocking. Control pulse to the input of transistor 1, a similar locking pulse is applied to the base of transistor 2 "

Unlocking the transistor 1 connects the negative input terminal to the beginning of the primary winding 6 of the power transformer 5 ,,

When the polarity of the control pulse changes, the transistor 1 locks up and the transistor 2 turns on unlocked. Since carrier dissipation is delayed in transistor 1, there is a period of conductivity of both transistors at the same time. The voltage drop across the diodes 10, 11 arising from the through-current action creates a negative connection and the offset of the operating points of the transistors 1, 2. As a result, the through-current is limited and the power loss in the transistors decreases. The transient process ends after a complete dissolution of the carriers in the transistor 1 and its reliable locking.

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During the resorption process, transistor 2 is in linear mode. The voltage drop across resistor 12 is subtracted from the control voltage.

transistors 2 and reduces the current of its base

Claims (1)

Claims of the invention A half-bridge transistor inverter comprising two inverters connected to the input voltages of the inverter according to a series-connected capacitor, the junction point of which forms the first output terminal of the inverter, two transistors of different conductivity type, connected by collectors to the input terminals of the inverter, and a control transformer with a primary winding connected to the control pulse generator, and secondary windings associated with the base transistor circuit, characterized in that, in order to reliability penalties by reducing dynamic losses when switching transistors, between the emitters of the transistors included is the first resistor inserted, shunted by the inserted chain of two respectively-connected first diodes connected according to the direction of conduction of the transistors, and the connection point of the first diodes is connected to the second output terminal through the entered second the diodes connected in opposite to the first diode, to each of the input terminals of the inverter, and the specified connection of the secondary windings is performed and so that each of them inserted through a second resistor connected between the base of one transistor and the emitter of the other transistor w