SU1686650A1 - Constant voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The purpose of the invention is to increase the reliability of the converter by preventing the saturation of the double-wrap throttle. The DC / DC converter + contains a transistor 1, a supporting element 2, a switching link 3, a two-winding choke, the second winding 5 of which is connected via diode 6 to the output terminals, the measuring element 7 and the control unit. When the converter operates, the current equal to the load current flows through the open transistor 1, and the differential current of the double-wound throttle and collector current of the transistor 1 passes through the switching link 3. When the difference current reaches a certain value detected by the measuring element 7, the switching link 3 turns off the transistor 1 and the energy of the two-winding throttles through the second winding 5 and the diode 6 enters the load. Since the current increment in the double-winding choke is fixed, the saturation mode of the specified choke does not occur. 2 Il. (L C 4

Description

about

00 O O

sl o

The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computer technology.

The aim of the invention is to increase the reliability of a constant voltage converter by preventing the saturation of a double-wound throttle.

Fig, 1 shows the electrical circuit of the converter; Fig. 2 shows current and voltage diagrams for converter elements.

The constant voltage converter contains a transistor 1, a supporting element 2, a switching link 3, a two-winding choke with the first winding 4, the second winding 5 of which is connected via diode 6 to the output terminals, the measuring element 7 and the control unit 8. The supporting element 2 consists of an emitter follower 9, a zener diode 10 and a decoupling diode 11, and the control unit 8 is designed as a generator 12 of the current source 13 of the locking signal and a threshold element 14, the source 13 of the locking signal consists of a matching stage 15, RC circuit 16 and a discharge diode 17. A resistor, a measuring transformer, an optocoupler diode, a transistor level converter, etc. can be installed as the measuring element 7. - with connection to the common wire of the device or isolated.

The purpose of the threshold element 14 is to give a pulse that permits the start of the source 13 of the blocking signal when the voltage at the input of the threshold element 14 reaches a certain level. The threshold element 14 (FIG. 1) can be performed on one inverter of a serial microcircuit 564ТЛ1, and the blocking source 13 can be in the form of an RC circuit 16 that specifies the duration of the blocking signal, the discharge diode 17 and the matching stage 15 on two inverters of the same microcircuit 564TL1. In a number of cases, the functions of the threshold element 14 and the source 13 of the blocking signal can be performed by a single device, and the input stage of the threshold element can perform the function of a residual current meter.

In the open state of the transistor 1 and the switching link 3, the voltage across the emitter load is equal to the reference voltage, and the voltage drop on the first winding 4 of the double winding drossel is switched to the collector and emitter of the transistor 1.

the difference between the input and the corresponding reference voltage. The current in the first winding 4 double-winding Drossel begins to grow (figure 2, 18), while through the power

the switching link circuit 3 flows a current equal to the difference between the current in the winding 4 and the current flowing into the collector of transistor 1. The rate of change of the difference current is determined by the voltage drop on coil 4, as well as the rate of change of current in the emitter circuit, which is proportional to the load current converter Since the measuring element 7 is located in series with the power circuit of the switching link 3 transistor, the voltage drop across it is determined by the difference current, and when the latter reaches a certain level corresponding to the switching level of the threshold element 14,

0, the switching element 14 is switched, its output impulse (FIG. 2, 19) permits the triggering of the source 13 of the blocking signal, which (FIG. 2, 20) locks through the current generator 12 for a fixed period of time

5, a transistor switching element 3 and a transistor 1, while the emitter circuit of the device is disconnected from the collector circuit. Termination of the current in the power circuit of the switching link 3 causes the output state of the threshold element 14 to return to its original position, and the self-induction voltage in the winding 5 of the double-winding droplet opens diode 6, maintaining the current in the winding of the load

5 converter. During the closed state of transistor 1, the current in the winding 5 decreases by a certain amount. Upon expiration of the pulse time at the output of the source 13 of the blocking signal, the switching link 3 and the transistor 1 open and the process repeats the current in the winding 4 of the double-wrap throttle and rises again. The time of the open transistor 1 and the switching link 3 is determined by

5, the time during which the differential current reaches a certain value. As a result, automatic balancing of current increments in the windings of 4.5 double-winding chokes against the average value determined by the collector current of transistor 1 is achieved, preventing the saturation of the choke windings and, consequently, increasing the reliability of the converter.

five

Claims (1)

Claims The DC / DC converter contains a transistor, the emitter of which is connected to the first output terminal, and the base is connected to the first output of the supporting element, the control unit, the output of which is connected to the control input of the switching link, the first power output of which is connected to the base of the transistor, and the second power output - to the junction point of the collector of the transistor and the first output of the first winding of the two-windowed drosell, the second output of which is connected to the first input output, and the second winding is connected via a diode to the output terminals, the block upravle0 Nor is it designed to form fixed locking signals, characterized in that, in order to increase reliability by preventing the saturation of a double-winding throttle, a measuring element is inserted that is connected by an input between the second input terminal and a second terminal of the supporting element, and an output is input to the input threshold element connected to the input of the control unit. /9 V MJI Lk.1 .0 20 Log.G fo Jtotro FI.2