SU1203662A1 - Stabilized d.c.voltage converter - Google Patents

Abstract

The invention allows to increase the reliability of obtaining a constant stable voltage due to the fact that a stabilized converter consisting of a series-connected self-exciting inverter with an output transformer (W) and a linear stabilizer (LS), whose input is bypassed by the first capacitor, and the output connected to the output terminals, an additional winding W, a second capacitor and a diode are inserted, and the positive output of the LAN is connected through the diode to the end of the additional winding W, the beginning of which ineno from the secondary winding end VT, and a second capacitor connected between the common point and the positive output obmotrk PM. 1 3. p. F-crystals, 3 ill. (About to about with O5 Oo

Description

The invention relates to electrical engineering and is intended for use in secondary power supplies.

The purpose of the invention is to simplify the design and increase reliability by using an asymmetrical mode of operation of a self-exciting inverter and a lightweight mode of operation of a control transistor in a stabilizer.

FIG. 1 is a schematic of a stabilized DC converter; in fig. 2 - voltage and current diagrams at various points of the circuit; in fig. 3 - stabilized voltage converter (second variant).

The stabilized converter (Fig. 1) contains a self-exciting two-stroke half-bridge inverter 1 with transistors 2 and 3, a capacitor 4, an output transformer 5 having a primary 6 and a secondary 7 winding. The beginning of the winding 7 through the diode 8 is connected to the positive input of the linear stabilizer 9, has a regulating transistor 10 connected between the input and output of the stabilizer 9, and a feedback divider 11 connected to the output terminals. The positive output of the linear stabilizer 9 is connected to the output terminal and to the end of the additional secondary winding 12 through the first diode 13, the beginning of the winding 12 is connected to the end of the winding 7 with the negative-} Pz1m input and output of the stabilizer 9 and with the minuses of capacitors 14 and 15, the advantages of which 1 Concretely connected to the input of the stabilizer 9 and to its output.

Additionally: 1nitel diodes 16 and 17 (Fig. 3) are connected by anodes to the negative input and output of a linear stabilizer 9, the cathode of diode 16 is connected through diode 8 to the positive input of stabilizer 9, and the cathode of diode 17 is connected to positive terminal of stabilizer 8, the cathodes of the additional diodes 16 and 17 11dk: poleny to the conclusions of the secondary winding 18 of the transformer 5.

The stabilized converter works as follows.

Suppose that the internal resistances of transistors 2 and 3 in the open state are zero, the voltage drop in the windings 6, 7 and 12 of transformer 5 and on the diodes 8 and 13 in the conducting state are also zero and, moreover, the process is oscillating. which in inverter 1 is established.

FIG. 2 shows diagrams; U ;; - network voltage; Di „- variation of network voltage; UG is the voltage in the primary winding of the transformer 5; Bo is the current through the regulating transistor.

From the moment ti, transistor 3 is open, and transistor 2 is closed. The voltage in the winding 6 is equal to the difference between the supply voltages and the capacitor 4, counted to the secondary winding 7, and is fed to the input stabil

0

five

of the jam 9. The feedback divider 11 is set to the desired output voltage, the difference in voltage at the input of the stabilizer 9 and at the output is applied to the regulating transistor 10, while the current flowing through this transistor is equal to the load current.

The voltage on the capacitor 15 is equal to the output voltage. At the moment ta, the transformer core 5 enters the mode

filling, as a result, voltage is re-charged in all windings of the transformer and inverter 1, while transistor 2 is open, transistor 3 is closed. The voltage in the winding 6 is equal to the voltage on the capacitor 4. This voltage, recalculated to the secondary winding 12, is equal to the voltage on the capacitor 15, which is equal to the voltage on the load 11. In this case, the transistor 10 closes and the current does not flow through it. The capacitor 4 is connected to the winding 6 through the transistor 2 until time point 3z, when the core of the transformer 5 comes back into saturation and the voltages in the transformer windings of the inverter 1 do not overwrite. Then the process repeats. The reasoning is valid if the capacitors 4 and 15 are large enough, i.e., the voltage on them stays at the same level in one period.

The areas of positive impulses are equal to the areas of negative impulses of a parasite in the windings. If the supply voltage at the input of the inverter has increased by the value of Li, the transistor 3 is open and the transistor 2 is closed (time interval t-i). Due to the fact that the capacitance of the capacitor 4 is large enough, the voltage on it is constant, then the amplitude of the voltage on the winding 6 increases by the value of Di ", therefore, the time of magnetization of the core 5 to the saturation state decreases in proportion to the increase

0, the voltage amplitude (ts) correspondingly decreases the open-state time of the transistor 10 and the voltage drop across it increases, since the voltage on the capacitor 15 also remains unchanged.

five

Since IG, transistor 2 is open and, due to the fact that the voltage across the capacitor 4 is constant, the time to saturation of the core (ir, -ts) remains equal to the tr-ts time and, consequently, the area of the pulses remains equal wives In the case of interference from the network in any of the time periods when transistor 3 is open, the duration of the positive pulse changes in proportion to the area of the interference and, therefore, it settles, recalculated by the secondary winding 7, on transistor 10. event of interference in time periods when

0

five

transistor 2 is open, its effect on the quality of the output voltage is zero.

In a real voltage drop circuit on elements 2, 3, 6-8, 12, and 13, the greater the greater the current flowing through them. Therefore, when the load current Ii2 is changed, the ratios of the voltages in elements 4 and 5 are changed so that the voltage on the load remains constant with

The positive output terminal is connected to the first output terminal, the negative output of the voltage regulator is connected to the second output terminal and the end of the secondary winding of the output transformer, characterized in that, in order to simplify and increase reliability, an additional winding of the output transformer, capacitor and The diode voltage regulator is made linear, and its predetermined degree of accuracy.

Two additional diodes 16 and 17, 10 positive output terminal through an additional diode connected to one output winding is connected to the end of additional 18, instead of windings 7 and 12 (Fig. 3), a positive winding, and the beginning of this process is made higher of the winding is connected to the end of secondary use of the transformer 5 of the inverter 1 of the output transformer, and the additional ones are more

formatter. In this case, the physics of the processes, the common point of the windings and the positive output of the voltage regulator.

2. The converter according to claim 1, distinguishes high manufacturability; the transfer capacitor is connected between the joint. At the same time, the physics of the processes occurring in the scheme remains the same.

Invention Formula

1. A stabilized DC voltage converter, a content connected by an input to the input terminals of a push-pull half-bridge self-exciting inverter, the secondary winding of the output transformer of which

and the third additional diodes, the anodes of which are connected to the negative output of a voltage regulator, the cathode of the second additional diode is connected to the beginning, and the cathode of the third additional diode to the end of the secondary winding

A channel is connected through a diode to a stabilized output transformer, the anode being connected to a voltage capacitor, the input of which of the external-magnitude additional diode is connected to the first capacitor, and the second cathode of the additional diode.

The positive output terminal is connected to the first output terminal, the negative output of the voltage regulator is connected to the second output terminal and the end of the secondary winding of the output transformer, characterized in that, in order to simplify and increase reliability, an additional winding of the output transformer, capacitor and the diode, the voltage regulator is made linear, and its positive output terminal is connected through the additional diode to the end of the additional winding, and the beginning of this winding is connected to the end The secondary winding of the output transformer and the third additional diodes, the anodes of which are connected to the negative output of the voltage regulator, the cathode of the second additional diode are connected to the beginning, and the cathode of the third additional diode to the end of the secondary winding

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Claims (2)

Claim 1. A stabilized DC-voltage converter ₂ , comprising a push-pull, half-bridge, self-excited inverter connected to the input terminals, the secondary winding of the output transformer of which is connected through a diode to a voltage stabilizer 25, the input of which is shunted by the first capacitor, and the positive output terminal connected to the first output terminal, the negative terminal of the voltage regulator is connected to the second output terminal and the end of the secondary winding of the output transformer Ora, characterized in that, in order to simplify and improve reliability, an additional winding of the output transformer, a capacitor and a diode are introduced into it, the voltage stabilizer is linear, and its positive output terminal through an additional diode is connected to the end of the additional winding, and the beginning of this winding is connected with the end of the secondary winding of the output transformer, and an additional capacitor is connected between the common point of the windings and the positive output of the voltage regulator. 2. The converter according to π. 1, characterized in that, the second and third additional diodes are introduced into it, the anodes of which are connected to the negative terminal of the voltage regulator, the cathode of the second additional diode is connected to the beginning, and the cathode of the third additional diode is connected to the end of the secondary winding of the output transformer, and the anode of the first additional the diode is connected to the cathode of the third additional diode. FIG. / Fig.Z