SU517115A1 - Transistor converter - Google Patents

Description

one

Scrapes are in the field of converter technology and can be used in power supply systems to convert a low level DC voltage to a high DC voltage.

The known transistor converters used for this task with feedback on load current have a limited voltage conversion ratio (output voltage range).

The goal of kooreteni is to expand the range of output voltages.

For this, the hopper transformer has an additional secondary winding, connected in series to the output circuit of the converter, via a video diode.

The diagram of the preferred converter is shown in the drawing.

The converter contains a transformer 1 with windings. The primary winding 2 has an output from the midpoint, which is connected to the minus of the power source 3 and the first 4 and the second 5 secondary windings. The beginning and end of the primary winding 2 of the transformer 1 are connected respectively to the collectors of the transistors 6 and 7, the emitters of which

connected to the plus source 3. The base of the transistor 7 is connected to the anode of the diode 8, the cathode of which is connected to the plus of the source 3. The base of the transistor 6 is connected to the common point of the anode of the diode 9 and the end of the secondary winding 4, the beginning of which through the capacitor 10 is connected to the base of the transistor 7. The cathode of the diode 9 is connected to the positive terminal of the load 11 of the converter and parallel to it a connected capacitor 12. A minus one terminal of the load 11 is connected to the beginning of the secondary winding 5, the end of which is connected to the beginning of the primary winding 2.

The device works as follows.

When the transistor 6 is open, the source 3 voltage is applied to the semi-winding of the primary winding 2 of transformer 1. The base current of the transistor 6 flows through the circuit: the emitter-base junction of the transistor 6, the secondary winding 4, the charging capacitor 10, the diode 8. In this half-period, the capacitor 10 charges It is applied almost to the voltage on the secondary winding 4, and the capacitor 12 is discharged to the load 11. The diode 9 prevents the discharge of the capacitor 12 through the secondary circuit. The transistor 7 is locked by the voltage on the diode 8.

The switching of the transistor 8 is accomplished by saturating the core of the transformer I with

the subsequent increase in the collector current of the open transistor and its output from the saturation state. In this case, the voltage drop across it increases, and the voltage on the secondary winding 4 decreases, and hence the base current of the transistor b. The condition that the transistor 6 is in saturation mode is violated, it closes, and transistor 7 opens.

With an open transistor 7, the load current 11 closes the loop: load 11, secondary winding 5, collector half winding 2, source 3, emitter-base junction of transistor 7 discharging capacitor 10, secondary winding 4, diode 9, charging capacitor 12 and load 11.

In this half-period, the total voltage is applied to the load 11: the power source V j; the capacitor 10 V2 (approximately equal to the voltage on the secondary winding 4), the voltage of the secondary windings V2, Vj and the voltage of the collector half winding of the primary winding 2.

The voltages between the electrodes of the closed transistors are equal at transistor 7

Web id; ikb id + 2i1,

where Od is the voltage drop across the diode 9; transistor 6

U3Q (Uc + Uj) 2U ;; (and, + u-,).

where Uj is the voltage of the secondary winding 4; load voltage

 + U2 + 2Ui.

It follows from these equations that the voltage at the transistors with the same voltage across the load is substantially less than in the known circuit.

Claims (1)

Invention Formula A current-feedback transistor converter containing two transistors, the emitters of which are connected to the first terminal of the power source and the output transformer, the primary winding of which is connected between the collectors of the transistors and is disconnected from the midpoint, and the first secondary winding is turned on through a capacitor between the bases of the transistors, the base of the first transistor connected via the first diode to the first output terminal of the converter, a second diode connected in parallel with the input of the second transistor, and a capacitor included between the output terminals of the converter, in order to expand the range of output voltages, the second the output terminal of the converter is connected to the beginning of the second secondary winding, the end of which is connected to the collector of the first transistor. four 2 2 12 0 3 + ten