SU1356166A1 - Push-pull inverter - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to increase the efficiency by eliminating the asymmetric mode of magnetization of the core of the output transformer. The magnetizing current of the orthogonal winding changes linearly with the symmetric mode of the magnetization reversal of the output transformer. After rectifying, the line voltage separated on the resistive current sensor enters the input of the threshold device after rectification. A signal from the threshold device introduces protection nodes that limit the growth of the magnetizing current. 1 hp f-ly, 3 ill. SO eaten O5 O5 O5

Description

The invention relates to electrical engineering and can be used in secondary power supply systems for converting a constant voltage to an alternating voltage.

The purpose of the invention is to increase the efficiency by eliminating the non-symmetrical mode of the magnetization reversal of the core of the output transformer,

FIG. 1 shows a diagram of one of the variants of the inverter; in fig. 2 (a, 6sB, rsA) - voltage diagrams on characteristic sections of the inverter circuit in a symmetric mode of operation; in fig. 3 (a5 6jBjr3De, g) the same in the asymmetrical mode of operation.

Push-pull inverter (Fig. 1) contains the power transistors 1 and 2; the bases of which through diodes 3 and 4 are connected to the auxiliary winding 5 of the control Transformer 6, the midpoint of this winding is connected through the auxiliary transistor 7 to the input supply terminal of the inverter. The base of the additional transistor 7 is connected to the output of the trigger 8, some of the inputs of which are connected through the first full-wave rectifier 9 and the capacitor 10 connected in series to the auxiliary winding 11 of the transformer 6. The second two-half-rectifier 12 is connected to the additional winding 13 output- TA transformer, which is placed on the core of the output transformer 14 orthogonally with respect to the main windings, is connected in series with a resistive sensor 15 and connected to a variable voltage source apr wife The second input trigger 8 via the threshold device 16 and the second full-wave rectifier 12 is connected to the resistive current sensor 16. It is advisable to use one of the windings, for example, 17, its transformer 6 (this circuit shown as a dotted line) To eliminate through-currents, any known technical solutions can be used (for example, shown by a dotted line).

Dvz stroke inverter works as follows.

When applied to the input winding of the transducer of the transformer 6 is controlled, its voltage is induced on all the windings by the alternating voltage coming

to the control inputs (bases) of the power transistors 1 and 2 (Fig. 2a). The differentiated voltage of the auxiliary winding 11 through the rectifier 9 post falls on the R input of the trigger 8 and wraps it around. At the trigger output, a zero-level signal is formed, closing the additional transistor 7. A variable voltage is applied to the windings of the output transformer, corresponding to the control signal (Fig. 2a, b, d). In the symmetric mode of magnetization reversal of the core of the output transformer 14, the magnetizing current 1 is changed linearly from the value. nor to anymore during the half cycle.

The magnetizing current of the additional orthogonal winding 13 also varies linearly. The linear voltage released on the resistive current sensor 15, is rectified in the second rectifier 12 and is fed to the input of the threshold device 16. In the symmetric mode, the value of Rl does not reach the trigger level of the threshold device 16, which causes the zero level at the output of the threshold device 16 (Fig. 2b). Thus, in the symmetric reversal mode, the control signal is transmitted without distortion, and the additional nodes do not affect the operation of the inverter. In the asymmetric mode of magnetization reversal of the core of the output transformer 14 (for example, in the case of asymmetrical reference voltage, as shown in Fig. 3A), the control voltage goes to the control inputs (bases) of the power transistors 1 and 2, and from the auxiliary winding 11 the voltage enters the R-input of the trigger 8, has zeroed its state. When this additional transistor 7 is closed. The stage of remagnetization of the core of the output transformer 14 begins, which, when the hysteresis loop reaches the knee, increases the magnetizing current in the additional winding circuit 13. The magnetisation current increasesI

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leads to an increase in incidence

neither the voltage on the resistive current sensor 15 and the excess level of the threshold device 16. The output of the threshold device 16

a single-level signal appears (in Fig. 3g), which causes trigger 8 to another steady state.

Additional transistor 7 opens and provides a forced; locking the open transistor 1 or 2. During the resorption time of transistor 1 (2), the core of the output transformer 14 (Fig. Sv) continues to be magnetized, which should be considered when choosing the threshold threshold device 16. After the dissolution time of the switching transistor 1 (2) in the output voltage, a pause is formed until the polarity of the output voltage is changed (Fig. Ze), which allows to eliminate the occurrence of an increase in the magnetizing peak of the current (Fig. Зж). When the polarity of the control voltage is changed, trigger 8 is zeroed out and all processes are repeated. Similarly, the processes run under control voltage with a pause at zero, the additional transistor 7 can simultaneously perform two functions: as an actuator of the SHTO signal generator and as a signal generator with equal volt-second intervals (with a difference in L Srace) The additional winding 13 is most easily on the cup core, inside which the main windings are located, and an additional winding 13 is wound through the central hole of the core. This winding in aggregate rezistivnm with a current sensor allows to obtain the most complete information on the state of the electromagnetic transformer core that allows to increase the inverter efficiency.

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Claims (2)

1. A push-pull inverter containing an output transformer, power transistors, the bases of which are connected to the additional winding of the control transformer through the corresponding diodes, the midpoint of which is connected to the input supply terminal through an additional transistor five the inverter, to which the emitters of power transistors are connected, the base of the additional transistor connected to the trigger output, one inputs of which through the serially connected first full-wave rectifier and capacitor are connected to the auxiliary winding of the control transformer, and the second two: half-period rectifier and additional winding of the output transformer , characterized in that, in order to increase the efficiency by eliminating asymmetrical re-magnetization of the output core, an inductor, a resistive current sensor and a threshold device are introduced, and the additional winding of the output transformer is placed on the core of the output transformer orthogonal with respect to the main transformer. the coils, connected in series with a resistive current sensor and connected to a source of alternating voltage, and the second trigger input through a threshold device and a second full-wave rectifier connected to a resistive sensor .. 2. The inverter according to claim 1, characterized in that one of the windings of the control transformer is used as a source of alternating voltage. : .X fis. . Compiled by V.Moin Editor M.Petrova Tehred L.Serdyukova Proofreader S.Cherni Order 5808/52 Circulation 659 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Design, k fie.Z