SU1658322A1 - Regulated dc voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in converter equipment. The purpose of the invention is improving the reliability of the converter and simplifying the filtering of the output voltage. The invention comprises a master oscillator 1, a first switch 2, a transformer 3, an output rectifier 5, a comparison circuit 8. Introduced node 4 protection, the second key 6 and the chain 7 correction. The correction circuit 7, the differential output signal of the master oscillator 1, each cycle through the second key 6 supplies the first key 2 short locking pulses, which allows to eliminate the input of the converter in the relay mode of operation and, as a consequence, reduce the voltage ripples at its output. The protection unit 4 protects the converter from overcurrent by increasing the duty cycle of the key 2 control pulses. 1 or FT FT L O (L 00 CJ N3 GO)

Description

The invention relates to electrical engineering and can be used in converter equipment.

The aim of the invention is to increase the reliability of the converter and simplify filtering.

The drawing shows a diagram of the Converter.

The converter comprises a master oscillator 1, a first switch 2, a transformer 3, a protection node 4, an output rectifier 5, a second switch 6, a correction circuit 7 and a comparison circuit 8.

The Converter operates as follows.

Two stabilized supply voltages are supplied to the inputs of the stabilized converter — a non-stabilized + DBX voltage, varying widely, and a stable + Don voltage supplied to the input of the comparison circuit 8 and for supplying the master oscillator 1. From the output of the master oscillator 1 square-wave pulses with an amplitude equal to + U0n, are fed to the input of key 2. The latter opens and the source of the UBX through the node 4 of protection, the primary winding of the transformer 3, the public key 2 begins to flow current, increasing linearly. When the key 2 is locked, the energy stored in the primary winding is transferred to the secondary winding of the transformer 3. The resulting voltage pulse is rectified by the rectifier 5 and charges its filter. The amplitude of the pulse is determined by the magnitude of the input voltage + 11in, the transformation ratio of the transformer 3 and the duty cycle of the pulses fed to the input of the key 2.

An increase in the voltage at the output of the converter will occur until its value reaches the value determined by the comparison circuit 8. In this case, the key 6 is opened, and the duty cycle of the pulses arriving at the input of the key 2 is increased. Since the input of the transistor of the key 2 is connected to the common bus through the low-impedance resistance of the public key 6, the turn-off time of the key 2 is reduced, and the dynamic losses are reduced.

Short positive voltage pulses, obtained by differentiation by circuit 7 of the correction of the positive front of the output pulses of the master oscillator 1, arrive at the input of the key 6 and open it. At the same time, a positive voltage is applied to the input of the key 2, which opens it with each pulse of the master oscillator 1, thereby eliminating the relay nature of the stabilized converter and reducing the amplitude of the output voltage ripple.

When increasing the voltage drop in the protection node 4 on the resistor R1 to a value equal to the opening threshold of the transistor Y, the latter opens and through the resistor R3

the positive voltage from the input voltage source + UBx is applied to the master oscillator 1. At the same time, the duty cycle of the master oscillator 1 increases and the current of the key 2 is limited to

given level. In the specified mode, the circuit can be indefinitely long. When overload or short-circuit is removed, the circuit is automatically restored to operation.

The level on the diode of the master oscillator 1 limits the voltage supplied to the master oscillator 1 to a value equal to its supply voltage +1) 0p.

Stabilized converter

DC contains the master oscillator 1, the primary key 2, the transformer 3, the protection node 4, the rectifier 5, the secondary key 6, the correction circuit 7 and the comparison circuit 8. Protection node 4 contains resistors R1

P2, NZi (transistor Y.

Claims (1)

Claims of the Invention A stabilized DC / DC converter containing a master oscillator is connected via a first switch to the primary winding of a transformer, the secondary winding of which is connected to an output rectifier output connected to the input of the comparison circuit, characterized in that In order to improve reliability and simplify filtering, a second key, a protection node and a correction circuit consisting of a series-connected capacitor and a resistor and inserted between the first input of the first switch and the input of the second switch covered by positive feedback through a capacitor, the output of the comparison circuit also connected to the input of the second switch, the power transition of which is connected between the second input of the first switch and the common bus, the input of the master oscillator through the first resistor is connected to the collector the transistor of the protection node whose control junction with the second resistor in series with it is connected in parallel to the third resistor connected in series with the transformer primary winding Torah.