SU797033A1 - Bridge-type inverter - Google Patents

Description

(54) BRIDGE INVERTER

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And 11, transformers, rectifiers 12 and 13, diode resistors 15-19, pins 20 and 21 for connecting the power supply, control element 22 (permanent magnet).

MTCs, assembled on transistors 2-5 and transformers 8 and 9, and additional transistors 6 and 7 form the shoulders of an inverter bridge circuit, to the output of which a load 1 is connected and the input — conclusions 20 and 21 — is connected to the source of the power cut. The additional windings 10 and 11 of the transformers 8 and 9 of the magnetically-transistor switches through the rectifiers 12 and 13 are connected respectively to the control inputs of the transistors 7 and 6. The average points bsoBbJXt of the windings of the MTK transformers are interconnected.

When voltage is applied to the circuit, the current of the MTC is excited, the transformer of which removes the control element (magnet 22), i.e. for the case shown in the diagram, the MTC will be excited on transistors 4 and 5. The EMF will be induced in all the windings of the transformer 9. Under the action of the EMF of the winding 11 through the base-emitter junction of the transistor b current flows, which ensures the transfer of the latter into the saturation mode. As a result, the load 1 is applied to the voltage with the polarity indicated in the diagram without brackets. The rotor of the motor comes into rotation. The magnet 22 moves, moves away from the transformer B and approaches the transformer 9, as a result of which the left (according to the scheme) MTC is excited, and the right goes out of the excitation state. Accordingly, the transistor 6 is locked and the transistor 7 is opened. The polarity of the voltage on the load 1 and the direction of the current in it will be different, as shown in the diagram in parentheses.

The direct connection between the middle points of the base windings of transformers of different MTCs ensures a clear simultaneous change of key sets and the transistors b and 7 controlled by them. Due to the electromagnetic connection of the windings 10 and 11 with the collector windings of transformers 8 and 9, the devices provide proportional current control of the transistors b and 7, i.e., the control current of these transistors is directly proportional to the load point. If the proportional current control of the transistors 2-5, as in the well-known inverter, is carried out by magnetic coupling between the collector and base windings of transformers 8 and 9, then in the proposed device there is optimally economical control of all power transistors. The diode 14 due to the flow through it of the base currents of the excited MTC ensures reliable locking of the transistors of the unexcited MTC. Resistors 15-17 create the conditions for driving the MTC, and resistors 18 and 19 ensure the locking of the g-7 transistors.

In relation to the known inverter, the control circuit of the proposed inverter is simplified, since the external control element affects only the two arms of the inverter bridge circuit.

invention formula

A bridge inverter containing controllable keys in each arm, two of which are magnetically-transistor keys, each of which is made according to an auto-oscillator circuit on two transistors and a saturable current transformer, which diverges from the midpoint of the primary winding of which forms the first power output of the key, and the ends This winding through these transistors are connected to the second power terminal switch, and the windings of the positive feedback of the transformer are connected to the input of these transistors, in order to simplify Two other key provided on power transistors, the input of each of which Isoedinen through a rectifier to the coil, additionally introduced into the transformer magnetically transistor switch arranged relative to a given power tranzis7 torus diagonal of the bridge circuit.

Sources of information taken into account in the examination

1. Electronic technology in automation. Sbornik.Sovetskoye radio, 197b vol. B, p.147, rice, 1.

2. US patent 3671844 cl. H 02 M 3/33, 1972.

3. USSR author's certificate number 547011, cl. H 02 M 3/135, 1970.

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Claims (1)

Claim A bridge inverter containing controllable keys in each arm, two of which are magnetic transistor keys, each of which is made according to an oscillator circuit with two transistors and a saturable current transformer, the tap from the midpoint of the primary winding of which forms the first power output of the key, and the ends of this windings through these transistors are connected to the second power terminal · key, and the transformer positive feedback windings are connected to the input of these transistors, due to the fact that, in order to simplify Two other key provided on power transistors, the input of each of kotoryhλ connected via a rectifier to the coil, additionally introduced into the transformer magnetically transistor switch arranged relative to a given power tranzis ^ torus diagonal of the bridge circuit.