SU1515288A1 - Single-ended converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power supply systems. The purpose of the invention is to increase the efficiency and expansion of the frequency range. In the single-ended converter, the primary winding 3 of the power transformer 4 is switched in phase-controlled transistors 1 and 2. When the transistors 1 and 2 are locked, the reactive energy of the power transformer 4 returns to the capacitor 13 through the recovery circuits 7 and 8. At the same time, the current of the recovery circuit 8 forcefully turns off the transistor 2 following the switching off of the transistor 1, the saturation depth of which is limited by means of a saturation limiting unit 9 connected to its electrodes. 2 hp f-ly, 1 ill.

Description

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315152

Ich (Brethren) is connected to electrohexinxes and can be used in systems of secondary electrons.

The purpose of the invention is to increase the efficiency of the expansion of the frequency range.

The drawing shows the proposed Converter circuit.

The prepackaged converter contains: first I and second 2 transistors, through which the primary winding 3 of the power transformer 4 is connected to the input terminals 5, 6 of the converter. The input terminal 5 is connected by a perpl1 transistor switch 1, as well as the output of the primary winding 3 via the first recovery circuit 7. The second output of this winding 3 is connected via the second recovery circuit 8 to the control input of the transistor 2, to the electrodes of the first transistor 1 The key of the restriction node 9, to the control inputs of the transistor switches I and 2 are connected the secondary windings of the control transformer 10, 1 connected to the control input 12 of the converter. A capacitor 13 is connected to the input terminals 5, 6. The secondary winding 14 of the transformer 4 is designed to be connected to the load (output pins 15, 16).

 Single-ended converter works as follows.

In the initial state, the supply voltage source is connected to the input terminals 5, 6, the capacitor 13 is charged, the transistors I, 2 are closed.

If rectangular pulses arrive at the input 12 of the converter, a transformer with windings 10, 11 forms the necessary voltage and current levels for controlling transistors 1 and 2.

When transistors 1, 2 are open, a power source is connected to the winding 3 of transformer 4, and a voltage is generated at output terminals 15, 16, the value of which is determined by the power of transformer 4, when transistors 1, 2 are closed, the energy stored transformer 4 during the open state of shreds, returns to capacitor 13 through recovery circuits 7, 8, which are made, for example, on diodes and an additional winding of a power transformer connected back-to-back with the primary winding. Due to

the difference in the resorption time of the transistors I, 2, one of them is locked first, for example a transistor. As a result, the winding 3 of the transformer 4 turns out to be shorted through the still open transistor 2 and the recovery circuit 8. Since at the beginning of the 1 {second moment the current in the winding 3 is equal to the load current, in the base-collector one. A junction current flows through the junction, which reduces the duration of the process of turning off the transistor and does not cause secondary breakdown. With the closed transistors 1, 2, the transformer core is demagnetized along the circuit: winding 3 of power transformer 4, diode 7, capacitor 13, winding 11 of the control transformer, base of transistor 2, diode 8. Excess energy of transformer 4 along this circuit returns to cowden - torus 13 and is partially supplied to the control source, which stores energy for the subsequent cycle of operation. Due to this operation algorithm, the transistor 2 is turned off almost immediately after locking the transistor 1, thereby excluding the voltage pause 1 due to the short circuit mode of the winding in the output voltage.

In order for transistor 1 to always be turned off first, a saturation limiting node 9 is introduced into it, which eliminates deep saturation, for example, by stabilizing the voltage at the emitter-collector junction. This switch forces the base current, at the expense of cheg the transistor enters preset saturation faster. At any load current, one voltage level is maintained at the transitions of the transistor

The process of locking transistor 2 is similar) as in a transistor switch with an emitter break, which expands the area of safe operation and the frequency range of the converter,

Claims (1)

1. A single-cycle converter containing a power transformer, the first and second primary of which through a first and second transistors are connected to the first and second input terminals of the converter, respectively, and 515 two recovery circuits, the first of which is connected to the second output of the primary winding of the power transformer, and the end to the first input terminal of the converter, and the second end is connected to the first output of the primary winding of the power transformer, and the input circuits of the transistors are connected to the secondary windings of the control transformer, characterized in that, in order to improve efficiency and expand the frequency range, the second recovery circuit is initially connected to the base of the second transistor, and 2886 to the electrodes of the first transistor of the subkeys, the introduced node of limiting its saturation. 2, the converter according to claim 1, in T is characterized in that each recovery circuit is configured as a diode. 10 3. The converter according to claim 1, about t is characterized in that each recuperative circuit is completed in the form of a series-connected diode and an additional winding of the power 5 transformer connected in opposite to its primary winding.