SU1325440A1 - Pulsed voltage stabilizer - Google Patents

Abstract

The invention relates to stabilized power sources with pulse control. The goal is to increase efficiency and reliability by increasing the accuracy of the protection operation and to obtain a sprung output voltage. To this end, the protection unit 15 is implemented on the transistor inverter 17, the output transistor 28, the integrating circuits x-21, 22, the resistor 27 and the diode 29. With the increase the load time of the locked state of the transistor 16- is increased, which leads to an increase in the voltage on the capacitor 25. With an increase in the load current above the nominal output transistor 28 opens, which causes the locking of the transistor 8. Ta; m occurs avalanche increase in the pulse width duration on the output 6 of PWM 1, HA sptsenie output transistor 28 of the relay 15 and the complete shutdown of the stabilizer by performing a pattern of positive feedback. 4 il. i (G C 1C ate 4; ii 4

Description

The invention relates to electrical engineering, in particular to stabilized power sources with pulsed regulation, and can be used to power various electronic and X-ray equipment.

The purpose of the invention is to increase the efficiency of the stabilizer, its reliability by increasing the accuracy of protection operation and obtaining a lower output voltage.

FIG. I is a block diagram of a pulse voltage regulator; in fig. 2 is a schematic diagram of one example of the practical implementation of the pulse stabilizer in FIG. 3 and 4 are schematic diagrams of other embodiments of the pulse stabilizer.

The pulse stabilizer (FIG. 1) contains a control unit made on the basis of a pulse-width modulator (PWM) 1, which is connected to the power output bus not 2 and the common bus 3 by the input terminals, and through the isolation diode 5 it is connected to the output power bus 2. To the output terminal 6 of PWM 1, the control input of the transistor cascade of the preamplifier 7 is connected, the transistor 8 of which is connected via a collector through a resistor 9 to the base transistor 10 of the power transistor

a switching transistor switch 11, which can be built both on one and a composite transistor, and the input transistor 10 of the power transistor 1I has the opposite type of conductivity compared to transistor 8 of the transistor cascade preamplifier 7. The output transistor of the power switch 11 is connected to The LCD filter 12. The stabilizer start-up unit 13 is connected to the input power bus and the common bus, and output 14 to the 4 PWM power supply 1. The protection unit 15 includes the transistor 16 of the inverter 17, the Base the transistor 16 through a matching resistor 18 is connected to the para-phase output 19 of the PWM 15 and the collector through the resistor 20 of the inverter 17 to the input power bus. The first collectors of the transistor 16 are connected by two integrating circuits 21 and 22, consisting of series-connected resistors 23, 24 and

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capacitors 25 and 26 respectively. The second terminals of the integrating chains 21 and 22 are connected to common atna 3. The integrating chains 21 and 22 have different integration times, and the second integrating chain 22 has a significantly longer integration time than the first. Parallel to the capacitor 25 of the first integrating circuit 21, a variable resistor 27 (or two series-connected resistors) is connected, the slider of which is connected to the base of the output transistor 28 and connected to the slider (middle output) of the variable resistor 27 through a diode 29 connected in the conducting direction (or zener diode) in reverse inclusion). The output 14 of the start-up unit 13 is connected to the first output of the blocking series 30 from the resistor 31 and the zener diode 32, the second output connected to the base of the transistor 16 of the inverter 17. The PWM 1 in FIG. 2 contains a pulse width modulator control unit 33, built on transistors 34 and 35, connected to an output bus 2 and a common stabilizer bus 3 by input circuits, a one-shot 36 with a controlled pulse width, including transistors 37-39 and part transistor cascade of preamplifier 7 on the transistor 40. IZHM 1 also includes the frequency control unit 41 of the pulse generator 42 on the transistor 43. The pulse generator 42 is built on transistors 44-48. The start block 13 is built on transistors 49 and 50 of the opposite conductivity type and contains timing elements in the form of a resistive divider consisting of resistors 51 and 52 and a capacitor 53.

The control input of the power transistor switch 11 is connected to the output of a resistor 9 connected to the collector circuit of the output transistor 54, which is included in the transistor cascade of the preamplifier 7 along with its input cascade on the transistor 40. The transistor 54, as well as transistor 8 ( Fig. 1), has the opposite type of conductivity compared to the transistor 10 of the power switching transistor switch 11.

FIG. 3 shows another embodiment of a pulsed voltage stabilizer, in which UttIM contains a feedback divider 55, a voltage source 56, a differential amplifier 57 on transistors 58-60, a multivibrator 61 on transistors 62 and 63, which is controlled by a differential amplifier 57 The transistor cascade of the preamplifier 7 is connected by a control input to the output of the multivibrator 61, and the output via a resistor 9 is connected to the control input of the power transistor switch 11 under the same condition regarding the conductivity types transistors as before

In the third exemplary embodiment (Fig. 4), a pulse stabilizer with an additional source 64 is built on the basis of an integrated circuit 65 of type K142EP1 and contains a differential amplifier 66 on transistors 67-70, feedback divider 71, reference source 72, emitter followers on transistors 73 and 74, Schmidt's trigger on transistors .75 and 76. The transistor cascade of preamplifier 7 on transistor 77 is connected to a collector through its matching resistor 78 with an input of the transistor cascade of preamplifier 7.9 per ton ranzistor 80 and 81, and the emitter through the output of the transistor 77 forms the output of 6 PWM 1. The startup unit 13 is performed on three transistors 49, 50 and 82, two of which 50 and 82 are of the opposite type of conduction, and an additional diode 83 connected between the emitter and the base of the transistor 50, the top contains the timing elements: a capacitor 53 and a resistive divider on the resistors 51 and 52. The output 14 of the trigger unit 13 is connected to the blocking chain 30 of the resistor 31 and the zener diode 32, which is connected to the second terminal control inputs inverter a 84 block 15 for shields. Inverter 84 has two inverting transistors 85 and 86. The base of the first one of them 85 forms the first control input of the inverter 84 and is connected via a resistor 87 to the collector of the second transistor 86, the base of which forms the second control input together with a matching resistor 88 77 output transistors. The collectors of transistors 85 and 86 through the resistors 20 and 89 of the inverter, respectively

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It is stately goedipgky with input power bus. The emitters of transistors 85 and 86 are connected to common bus 3.

The pulse voltage regulator (Fig. I) works as follows.

When a constant unstabilized voltage is applied to the input power bus from the output 14 of the start-up unit 13, the voltage pulse 4 is supplied to the power supply bus 4, which simultaneously enters the base of the transistor 16 of the protection unit 15 through a resistor 31 and a zener diode 32. The PWM 1 output signal from the output 6 is fed to the input of the transistor 8 of the amplifier stage 7, in the collector circuit of which a current arises. The corresponding current begins to flow through the power switching transistor switch 11, and on the output bus 2 of the stabilizer, the voltage determined by the parameters of the PWM I input circuits (the feedback divider and the source of the reference voltage in Fig. 1 are not shown) is shown. Upon termination of the triggering pulse, the trigger unit 13 is locked by the output voltage of the stabilizer, which comes through a separating diode 5 connected to the output bus 2 in the conductive direction, and the zener diode 32 is locked. When the load on the stabilizer changes, the ratio of the durations of time to output is fixed.

6SHIM 1 there are high and low potentials varying. In the period of time when the preamplifier

7 is open, the transistor 16 of the protection unit 15 is locked, since its base receives pulses from the paraphase output 19 of PWM I, and the capacitors 25 and 26 of the integrating circuits 21 and 22 are charged. The capacitor 26 of the second integrating circuit 22 is charged to a voltage significantly lower than the capacitor 25 of the first integrating circuit 21.

In the period of time when the transistor 8 is closed, i.e. the output 6 of PWM 1 has a low potential, both capacitors 25 and 26 discharge through resistors 23 and 24 of their own circuits 2 to 22 and the saturated transistor 16 of block 15. As the load increases, the time of the locked state of the transistor 16 increases, which leads to an increase in voltage on the capacitor 25 of the circuit 21. When the load current increases above the nominal output transistor 28 of the protection device 15 opens, and the current from output 6 of PWM 1 flows through the device transistor 28 15 protection. The epargs entered on the stabilizer bus 2 will decrease, which will lead to a drop in voltage on the bus 2 of the stabilizer, and this, in turn, will increase the duration of the pulse at output 6 of HIM 1 and further increase the average component capacitors 25 and 26, which will lead to almost instantaneous saturation of the output transistor 28 of the protection unit 15 with a simultaneous increase in the pulse duration at the output 6 of the PWM 1 while simultaneously stopping the flow of energy to the stabilizer bus 2, i.e. the transistor will lock out 8.

Thus, an avalanche-like increase in the pulse width at the output 6 of PWM 1 occurs, the output of the high-voltage transistor 28 of the protection block 15 and the stabilizer are completely turned off, due to positive feedback in the circuit For more reliable saturation of the output transistor 28 serves as the second integrator circuit 22, the resistance value of the resistor 24 of which is chosen to be significantly less than the resistance value of the resistor 23 of the first integrating circuit 21. When the transistor 16 is closed, the capacitor 26 is charged value sufficient for triggering the diode 29 and the transistor 28 enters a deeper saturation

ensuring reliable shutdown of a hundred

bilizer After enough time has passed to restore the starting block 13, it will generate a pulse, which will apply a voltage on the PWM and block the operation of the protection block 15 for a short time. In this case, in the case of a short circuit, either at the output or a large overload, the overload current cannot exceed the value determined by the resistor 9. When the start-up impulse ends, the stabilizer turns off again for a long time.

If there is no overload, the stabilizer will automatically enter normal mode. If an overload occurs, the stabilizer is turned off as described above. In this case, the magnitude of the current overload

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ki can be installed, prg.kticheski, with any kind of accuracy, Depending on the characteristics of the circuit diagram of the pulse stabilizer, the features of the execution circuits of the control unit of the pulse stabilizer, the specific design of the protection unit 15 can be changed. In this case, the course of physical processes in the stabilizer may vary somewhat. ,

The stabilizer (Fig. 2) works as follows.

When power is applied to the input terminal, i.e. On the collector of the output transistor of the power switch 11, with a delay determined by the capacitance value of the capacitor 53 and the resistance value of the resistors 51 and 52 of the trigger unit 13, a trigger pulse appears at its output 14, which prohibits the operation of the protection unit 15 (during this period the output transistor 28 of the protection unit 15 is locked because the starting pulse exceeds the potential of the breakdown of the Zener diode 32 of the blocking chain 30) and supplies the supply voltage to the power supply bus 4 of the PWM control unit 33 1. The stabilizer is turned on at a lower frequency. During the start-up process, the voltage on the output buses 2 and 3 of the stabilizer increases, the frequency of the pulse generator 42 and the output voltage of the stabilizer reach their nominal value, the start pulse ends, and the start-up unit 13 through diode 5 is locked by the output voltage of the stabilizer. At the same time, the zener diode 32 is locked.

As the load increases, the open time of the power transistor switch I increases, which leads to an increase in the voltage on the capacitors 25 and 26 of the integrating circuits 21 and 22 of the protection unit 15, and consequently on the basis of the transistor 28 of the block 15 bans. With trans. the nominal load current of the transistor 28 will open and instantaneously enter saturation due to the occurrence of a positive feedback in the stabilizer circuit (as described for the flowchart in Fig. 1). Therefore, the stabilizer is turned off. When the capacitor 53 of the starting block 13 is recharged to a voltage sufficient to operate on the block 13 for

start-up, the stabilizer is switched on again for a short time. During this period, the maximum overload current cannot exceed the current determined by the resistor 9 of the collector circuit of the transistor 54 of the preamplifier 7. When the overload disappears, the stabilizer automatically enters the normal mode.

The stabilizer (Fig. 3) works as follows.

When the supply voltage is applied to the input of the stabilizer, a start pulse appears on the supply bus A and FM 1, which prohibits the operation of the protection unit 15 (as in the block diagram of Fig. 1). At the output power busbars 2 and 3 of the stabilizer, in the absence of overload, the voltage gradually increases and reaches its nominal value. In the event of an overload, the stabilizer is turned off (as in the block diagram in Fig. 1). In the event of an overload at the moment the stabilizer turns on, when a start pulse appears at output 14 of the start block 13, the overload current of the power switch 11 does not exceed the current detected by the preamplifier collector 9 resistor. 7 After the start pulse terminates, the stabilizer turns off.

The stabilizer (Fig. 4) works as follows.

Due to the additional inverting transistor 86 of the protection unit 15, the base of which is connected to the collector through the matching resistor 88

A pulse voltage regulator containing a power switching transistor switch connected in series to the power bus, the control input which is connected to the output of the transistor cascade of the preamplifier formed by the transistor of the opposite type of conductivity with respect to the input transistor of the power transistor switch that controls the transistor 77 , the charge of the capacitors 25 and 26 of the integrating circuits 21 of the house connected to the output of the unit upi 22 occurs synchronously with the inclusion of the Sy1 transition iterated key 11.

Thus, the implementation of the protection unit on two or three transistors, one or two of which are 5 with inverters operating in key mode, and one output actuating transistor and two integrating circuits with their connections to each other and with known parts mi pulse Q voltage stabilizer increases the efficiency of the stabilizer. Exclusion of a transistor operating in a linear mode and supplying the entire control circuit with a stabilizer from the protection unit reduces the power loss in the stabilizer, increases the accuracy of the protection, since the protection unit responds to the width

made on the basis of a pulse-width modulator, the input circuits connected to the power output and common buses, and the power bus through a separating diode connected to the power output bus, the trigger unit, the inputs connected to the input power and common buses, and output to the power supply bus of the control unit, a protection unit, characterized in that, in order to obtain a lower voltage at the output of the stabilizer, as well as to increase the efficiency and reliability of the stabilizer by increasing the accuracy of the protection, the protection unit en on the transistor inverter, the output transistor and two parallel-connected integrating circuits,

pulse, the power transistor, which depends on the magnitude of the load, rather than the magnitude of the output voltage, while in the known device the reduction of the output voltage to a value sufficient to lock the protection transistor can occur at very significant current overloads, t . against overloads in the known device is practically a short circuit protection. In addition, the exclusion from the protection unit of the transistor operating in the linear mode and feeding from the output of the stabilizer, for which normal operation, an additional voltage is necessary, ensuring its operation in the linear mode, allows to obtain a lower output voltage of the stabilizer. An increase in the efficiency of the stabilizer, along with an increase in the accuracy of protection, is also given by the reliability of the stabilizer.

Claims (1)

Invention Formula A pulse voltage regulator containing a power switching transistor switch connected in series to the power bus, the control input which is connected to the output of the transistor cascade of the preamplifier formed by an opposite type transistor of the power transistor switch controlling the input transistor connected to output of the unit upde connected to the output of the control unit, made on the basis of a pulse-width modulator, with input circuits A power bus and a common busbar, and a power bus through an isolating diode connected to the power bus bus, a start-up unit, inputs connected to the power bus and a common bus, and an output to the power bus of the control unit; in order to obtain a lower voltage at the output of the stabilizer, as well as to increase the efficiency and reliability of the stabilizer by increasing the accuracy of the protection, the protection unit is made on a transistor inverter, an output transistor, and two the connecting circuits formed by each series connection of a resistor and a capacitor; the first leads of the integrating resistors are connected to the collector of the inverter transistor, the connector — to the foot through the inverter resistor to the power input bus; the control input of the inverter is connected via a matching resistor to the paraphase output of the control unit , the base of the output transistor is connected to the middle terminal of the variable resistor connected to the common terminal of the resistor of the first integrating circuit, to the base of the output resistor of the transistor is connected Jq | 5 5440 10 Also, the diode in the conductive connection, the second terminal of which is connected to the common terminal of the resistor and capacitor of the second integrating circuit, the collector of the output transistor is connected to the control input of the transistor cascade of the preamplifier, between the output of the startup unit and the base of the transistor of the inverter is turned on A sequential blocking chain of a resistor and a zener diode, the emitters of the transistors of the protection unit and the second terminals of the capacitors of the integrating circuits are connected to a common bus. Lg Compiled by S.Gorbachev Editor NoEgorov Tehred A. Kravchuk Order 3108/43 Circulation 863 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader M. Demchik