SU1571732A1 - Push-pull resonance dc voltage 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 reliability by reducing the peak power dissipated in the power transistor when it is switched. The converter control unit 6 contains two identical channels of forced latching of the power transistor 4 (5). Each of these channels contains an additional power supply 8 connected via an additional transistor 9 and the first diode 10 to the base-collector junction of the power transistor 4 (5). The auxiliary transistor 9 is controlled by a current transformer 16 included in the output circuit of the converter. When the output current of the converter is reduced to zero, the additional transistor 9 is unlocked and under the action of the voltage of the additional power source 8, the forced locking of the power transistor 4 (5) occurs. 2 Il.

Description

(21) 4470615 / 24-07

(22) 08/01/88

(46) 06/15/90. Bul № 22 (72) A.P. Ponomarev

(53) 621.314.58 (088.8)

(56) US Patent No. 4017784, cl. 3121-2, 1977.

US patent No. 3596165 ,. Cl.321 / 2, 1971.

(54) DOUBLE-TAKE RESONANT CONSTANT VOLTAGE CONVERTER

(57) The invention relates to electrical engineering and can be used in secondary power supply systems. The purpose of the invention is to increase reliability by reducing peak power,

dissipated in power transistors when switching. The converter control unit 6 contains two identical channels of forced latching of the power transistor 4 (5), each of which contains an additional power supply 8 connected through an additional transistor 9 and the first diode 10 to the base-collector junction of the power transistor 4 (5). The auxiliary transistor 9 is controlled by a current transformer 16 included in the output circuit of the converter. When the output current of the converter is reduced to zero, the additional transistor 9 is unlocked and under the action of the voltage of the additional power source 8, the forced locking of the power transistor 4 (5) occurs. 2 Il.

with

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

The purpose of the invention is to increase reliability by reducing the peak power dissipated in the power transistors when they are switched.

Fig. 1 shows a structural diagram of a push-pull resonant constant-voltage converter, a voltage; 2 shows timing diagrams for his work.

In the power circuit, the converter (Fig. 1) contains an output circuit with a resonant circuit 1, a capacitive voltage divider on capacitors 2 and 3, and power transistors 4 and 5.

The converter control unit 6 includes a generator of control pulses 7 connected to the output bases of power transistors 4 and 5, and two identical channels of forced locking of the power transistor, each of which consists of an additional power source 8 connected through an additional transistor 1 9 and the first diode 10 to the transition base-collector of the power transistor 4 (5) in the blocking direction. The input circuit of the additional transistor is shunted by the oppositely connected second diode 11 and through the first resistor 12 and the second diode 13 is connected to the secondary winding 14 (15) of the current transformer 16 shunted by the second resistor 17 The primary winding 18 of the current transformer 16 is connected in series. to the output converter circuit. The transition base-collector of the additional transistor 9 is shunted by the third resistor 19.

The Converter operates as follows.

The control pulses come from the generator 7 to the bases of the power transistors 4 and 5 (Fig. 2, diagrams 20 and 21). Transistors 4 and 5 and the output resonant circuit 1 pass current half-waves of almost sinusoidal form (Figure 2, diagram 22). The passage through the primary winding 18 of the current transformer 16, this current is transformed into its secondary windings 14 and 15, the shape of current on which (figure 2, diagrams 23 and 24J due to the imperfection of the transformer 1 o current and, depending on its load, differs from the shape of the primary current.

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0 5 Q o

., five

five

Changing the load of the secondary windings 14 and 15 of the current transformer by selecting the resistance of the resistors 12 and 17, selects the required amount of advance of the current through zero in the secondary windings relative to the primary one. At the same time, before the end of the current through the first power thermistor 4, the current in the first secondary winding 14 of the current transformer 16 passes through zero (figure 2, diagram 23), which leads to the opening of transistor 9 (figure 2, diagram 24 base-emitter voltage transistor 9), and to the junction a collector is the base of the power transistor 4 through the open transistor 9 and the diode 10 is applied a block voltage from the additional power source 8. This leads to the forced locking of the first power transistor 4 and the growth of the collector voltage on it. When the collector voltage exceeds the value of the output voltage of the additional power supply 8, the diode 10 is closed and the current consumed from the additional power supply 8 is terminated. Similarly, the forced locking of the second power transistor 5 occurs at the end of the current passing through it.

The provision of forced locking of power transistors 4 and 5 excludes the development of through currents through them, which can cause overheating and their failure, as a result, the reliability of the converter increases,

In addition, the reduction of the closing time of the power transistors 4 and 5 makes it possible to increase the frequency of the output voltage of the converter.

Claims (1)

Invention Formula A push-pull DC resonant converter, containing two power transistors and a current transformer with two secondary windings and a primary winding, connected in series to the output circuit of the converter, and a control unit whose outputs are connected to the power transistor base circuits, characterized in that to increase reliability by reducing peak power when switching, the control unit contains two identical channels of forced locking of the power transistor, each of which consists of an additional power source connected through an additional transistor connected in series and the first diode to the base-to-junction transition of the corresponding power transistor, input circuit additional Compiler V. Moin Editor A. Lezhnin Tehred MG Khodanych Order 1520 Circulation 499 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, .Raushsk nab. 4/5 717326 The main transistor is shunted by a second diode connected in opposite and through the first resistor and the third bottom connected in series to the locking directions of this transistor connected to the corresponding secondary current transformer winding shunted by the second resistor, and the third resistor is connected parallel to the base-collector transition of the additional transistor. five ten Proofreader V. Kabatsky Subscription