SU773872A1 - Converter - Google Patents

Description

54) CONVERTER

The invention relates to electrical engineering and can be used in the development of secondary power sources. The converters connecting the auto-generator and the power amplifier are known, the inputs of which are combined and are the input of the device 1 and 2. A disadvantage of the known converters is the presence of currents during switching of the transistors of the power amplifier, which cause additional power losses. The closest technical solution is a converter containing a transformer feedback oscillator, the transistor bases of which are connected via diodes to the output of a key element connected to a rectifier fed from the auxiliary winding of the transformer 3. Disadvantage of this device is the presence of through currents in the case of using a power amplifier, in connection with the absence of a pause in the output voltage of the oscillator. The aim of the invention is to increase the efficiency of the converter due to the elimination of "through currents. The goal is achieved by the fact that the converter containing a transformer, the power winding of which is connected to the power transitions of two transistors, controls which transitions through limiting resistors are connected to the base windings of the transformer, while the bases of the transistors are connected through diodes to the output of the key element, and a rectifier associated with the additional winding of the tra} 1formator, a delay impulse driver and a differentiating capacitor connected to the AC circuit, referred to as nute vyp1r mitel. whose output is connected to the driver input, and the output of the latter is connected to the input of the key element. FIG. 1 shows a converter block diagram; in fig. 2 - stress diagrams. The converter consists of an auto-oscillator 1, containing a transformer 2 and transistors 3, 4, connected by collectors with power supply cables, and with emitters - with horses of a primary winding of a transformer 2, whose midpoint is connected to another power line; the basic windings of a transformer 2 are connected to the emitters of transistors 3, 4 and bases through the resistors 5, 6. Moreover, between the collector and the emitter of the transistors 3, 4 are included the starting resistors 7, 8 the output of the auto-oscillator 1 is connected to the control input of the power amplifier 9 connected to the ladder power, and its output is the output device. The transformer 2 winding through differentiating capacitor 10 is connected to the input of a bridge rectifier 11, the output of which is connected to the input of a delay pulse generator 12 connected by an output to the control input of the key 13, and its input is connected to the middle point of the primary winding of the transformer 2. The output of the key 13 is connected with the same electrodes of the diodes 14, 15, the other electrodes of which are connected to the bases of the transistors 3, 4, and the driver 12 is also connected to the power supply lines.

The device works as follows.

When the converter is connected to a constant voltage, the oscillator 1 begins to generate square-wave pulses (Fig. 2, 1). The differentiating circuit formed by the differentiating capacitor 10 and the input impedance of the delay pulse shaper 12 differentiates the square pulses, and the bridge rectifier 11 corrects their polarity of the delay pulse 12 needed to start (Fig.2.2). The swept pulses (Fig. 2.3) arrive at the key 13, opening it. The transistors 3, 4 are closed and in the rectangular output voltage a pause "at zero" is formed, equal to the duration of the expansion of the pulse. After the end of the pulse, the key 13 closes and the starting resistors 7, 8 of the oscillator I apply a positive bias to open the transistors 3, 4 of the oscillator 1. Moreover, the one of the transistor that was closed before this process is opened, since the primary half winding for this transistor has the maximum resistance, and the switching current will be the lowest. When using in an amplifier 9, the power of the transistors having a three-time restoration of the closed state, the driver of the delay pulse driver must be selected from

relations

t. (Fig. 2.3.).

The formation of a discrete pause "at zero in the rectangular voltage of the oscillator 1 allows to completely eliminate the" through currents in the transistors of the amplifier 9 to power.

The proposed converter makes it possible to significantly increase the efficiency of the converting device due to the complete elimination of "through currents in converting current with large multiplicity

load.

Claims (3)

1. Moin VS, Laptev N. N. Stabilized transistor converters. 0 M., “Energie, 1972. p. 239. 2. EM Romashch. Transistor Converters in Electronic Equipment Power Supplies. M., Energie, 1975, p. 12 3. Moin VS, Laptev N. N. Stabilized transistor converters M., “Energie, 1972, p. 314.