CN109347329A - A kind of converter for DC to DC - Google Patents
A kind of converter for DC to DC Download PDFInfo
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- CN109347329A CN109347329A CN201811310413.4A CN201811310413A CN109347329A CN 109347329 A CN109347329 A CN 109347329A CN 201811310413 A CN201811310413 A CN 201811310413A CN 109347329 A CN109347329 A CN 109347329A
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a kind of converters for DC to DC, including main circuit, the DC voltage for will be inputted, and after being boosted or being depressured, export to external electric equipment；The main circuit is connected with input undervoltage protection circuit, input overcurrent protection circuit, the under-voltage and overvoltage crowbar of output respectively；Wherein, input undervoltage protection circuit, for carrying out input undervoltage protection to main circuit；Input overcurrent protection circuit, for carrying out input overcurrent protection to main circuit；Under-voltage and overvoltage crowbar is exported for carrying out exporting under-voltage and output over-voltage protection to main circuit.A kind of converter for DC to DC disclosed by the invention; the protection circuit function that it has is comprehensive; it can be realized input undervoltage protection, input overcurrent protection, output under-voltage protection and output over-voltage protection; it is simple and reasonable; various defencive functions can be realized using only common device; manufacturing cost relative moderate, good reliability.
Description
Technical field
The present invention relates to technical field of circuit design, more particularly to a kind of converter for DC to DC.
Background technique
It is that modern high frequency Switching Power Supply is most basic currently, being used for the converter (i.e. DC-DC converter) of DC to DC
Component, required for known DC input voitage is converted by it or wieldy DC output voltage.
With the development of electronic technology, the function of electronic equipment is more and more various and perfect, and the requirement to power supply is also more next
Higher, the performance superiority and inferiority of power supply and all technical and reliability of electronic equipment are closely bound up, and DC-DC converter is
It is widely used in portable electronic product.
For DC power supply, need to consider Railway Project:
1, outputting and inputting for power supply should all have relatively-stationary operating voltage range, and input voltage is too low to will lead to electricity
Partial circuit cisco unity malfunction in source, output voltage is too low to will lead to load (such as electronic chip) cisco unity malfunction,
And excessively high output voltage can burn electronic product, abnormal input voltage and output voltage can all cause power supply and electronics to produce
The damage of product reduces its service life；
2, power supply should have stable input current, and excessively high input current also results in the damage of secondary power supply.Institute
With must the management that standardizes of operating voltage to secondary power supply and electric current, form comprehensive protection circuit.Defencive function
Perfect power supply is able to extend power source life, improves system reliability, can be automatically into when power supply external circuit breaks down
Guard mode and be unlikely to permanent failure, can restore normal automatically after the disappearance of some external faults, guarantee the safety of system.
With the design of integrated circuit and the progress of manufacturing technology, various switching power source chips largely come out, this chip
Can be integrated in one module by control, driving, protection, detection, as long as designing good external circuits, DC-can be realized
DC inverter functionality, reduces small product size, improves reliability.How to design external circuits make switching power source chip and
MOSFET plays a role, and realizes that accurate, reliable, the efficient work of Switching Power Supply is the emphasis studied at present.
For existing DC-DC converter protection circuit, type is relatively more.Wherein, input undervoltage protection circuit is most
Need external reference voltage to carry out the comparison of level, need to realize using integrated circuit, need additional attention reference voltage source and
The design of comparator, circuit structure is complicated, increases protection circuit cost, while integrated circuit selection and performance quality, significantly
Affect the validity and reliability of circuit.
And input overcurrent protection circuit is commonly related to a cut-off current at present, that is, input current when working normally,
The surge current of booting moment is had ignored, if cut-off current does not consider surge current, frequently can lead to surge current triggering current limliting
Circuit operation is protected, the malfunction of circuit is caused.Meanwhile current foldback circuit needs a current value, common way is to use
Hall element obtains current signal, and Hall element sample volume is bigger and expensive, can reduce measurement accuracy simultaneously
Improve the development cost of entire power supply.
In addition, existing output overvoltage and the traditional method of under-voltage protection are thyristor short-circuit protections, for example, when output electricity
When pressing through high, turn on thyristors is triggered, so that output terminal shortcircuit is caused overcurrent, is cut input by fuse or circuit protection
It is disconnected, to protect load.But this method threshold voltage is easy to produce fluctuation, while temperature is affected to it, is easy to produce
Malfunction, reduces reliability.
Therefore, it can be realized input undervoltage there is an urgent need to develop a kind of converter for DC to DC out at present
Protection, input overcurrent protection, output under-voltage protection and output over-voltage protection, simple and reasonable, manufacturing cost relative moderate can
It is good by property, be conducive to circuit protection.
The protection circuit function of DC-DC converter is comprehensive, and input undervoltage protection, input overcurrent protection, output may be implemented
The common devices such as resistance, capacitor, diode, voltage-stabiliser tube, triode, comparator are used only in under-voltage protection and output over-voltage protection
Various defencive functions can be realized, therefore greatly reduce the cost for inputting circuit under proteciton, and facilitate debugging, improve circuit
Reliability.
Summary of the invention
In view of this, the protection having is electric the object of the present invention is to provide a kind of converter for DC to DC
Road is full-featured, can be realized input undervoltage protection, input overcurrent protection, output under-voltage protection and output over-voltage protection, structure
Advantages of simple, manufacturing cost relative moderate, good reliability are conducive to circuit protection, are conducive to produce extensively and popularize, have great
Production practices meaning.
For this purpose, the present invention provides a kind of converter for DC to DC, including main circuit, for will be inputted
DC voltage after being boosted or being depressured, is exported to external electric equipment；
The main circuit, respectively with input undervoltage protection circuit, input overcurrent protection circuit, export under-voltage and overvoltage protection
Circuit is connected；
Wherein, input undervoltage protection circuit, for carrying out input undervoltage protection to main circuit；
Input overcurrent protection circuit, for carrying out input overcurrent protection to main circuit；
Under-voltage and overvoltage crowbar is exported for carrying out exporting under-voltage and output over-voltage protection to main circuit.
Wherein: pulse width modulates chip IC；
1 pin of the pulse width modulation chip IC is connected with first voltage control signal VA；
2 pins of pulse width modulation chip IC respectively with capacitor C2, resistance R5, resistance R2, resistance R3 and resistance
R4 is connected；
Capacitor C2 is connected with first voltage control signal VA；
Resistance R5 is connected by capacitor C3 with first voltage control signal VA；
Ground connection after resistance R3 and resistance R4 is parallel with one another；
Resistance R2 connects with resistance R1；
Resistance R1 is connected with an output feedback voltage end U0 respectively；
The output feedback voltage end U0 connects with the anode of diode D1, the cathode of diode D1 connect respectively capacitor C1 and
The cathode of diode D2；
Capacitor C1 ground connection, the anode of diode D2 connect with the emitter of a triode Q1；
The base stage of triode Q1 respectively with the cathode of zener diode DW1, resistance R7 and second voltage control signal VB
Connect；
The plus earth of zener diode DW1；
The collector of triode Q1 connects with resistance R6；
Resistance R6 and resistance R7 confluence after, respectively with resistance R11, capacitor C7, resistance R18, capacitor C8, the second DC voltage
The voltage input-terminal 1 of input terminal V2 and transformer T1 connects；
Resistance R11 and capacitor C7 also connect with the cathode of diode D5, and the anode of diode D5 passes through a resistance R12 points
Do not connect with the drain electrode of the voltage input-terminal 2 of transformer T1 and a switching tube M1；
The source electrode of switching tube M1 connects with resistance R16 and resistance R17 respectively, resistance R16 and resistance R17 ground connection；
The grid of switching tube M1 connects with resistance R14, the anode of diode D4 and resistance R15 respectively；
Resistance R15 connects with resistance R16；
6 pins of pulse width modulation chip IC respectively with the cathode of diode D3, resistance R14 and resistance R13 phase
It connects, resistance R13 connects with the cathode of diode D4；
The 5 pins ground connection of the pulse width modulation chip IC；
7 pins of the pulse width modulation chip IC connect with the cathode of the diode D1；
8 pins and capacitor C6 of the pulse width modulation chip IC connect；Capacitor C6 ground connection；
3 pins of the pulse width modulation chip IC connect with capacitor C4 and resistance R10 respectively；Capacitor C4 ground connection；
Resistance R10 connects with resistance R15 and resistance R16 respectively；
4 pins of the pulse width modulation chip IC connect with capacitor C5 and resistance R8, resistance R9 respectively；Capacitor C5 connects
Connect after ground, the resistance R8 and resistance R9 parallel connection in capacitor C6；
The output feedback voltage end U0 also connects with the cathode of one end of capacitor C10 and diode D6 respectively；
The anode of diode D6 connects with the output voltage terminals 6 of transformer T1, the other end of capacitor C10 respectively with transformation
The output voltage terminals 5 of device T1 connect and are grounded；
It is parallel with capacitor C11 and capacitor C12 respectively between the output voltage terminals 3 and output voltage terminals 4 of transformer T1,
One end of the capacitor C12 is grounded；
Capacitor C13 is parallel between the output voltage terminals 7 and output voltage terminals 8 of transformer T1, the capacitor C13's
One end ground connection.
Wherein, the both ends of the capacitor C12 are parallel with connecting terminal P1 and connecting terminal P2；
The both ends of the capacitor C13 are parallel with connecting terminal P3 and connecting terminal P4.
Wherein, transformer T1 further includes the voltage output group being made of output voltage terminals 9 and output voltage terminals 10, with
And the voltage output group being made of output voltage terminals 11 and output voltage terminals 12.
Wherein, the input undervoltage protection circuit includes the first DC voltage input end V1；
First DC voltage input end V1 is connected with resistance RB1, resistance R22, resistance R25 and resistance R27 respectively；
Resistance RB1 connects with capacitor C14 and resistance RB2 respectively；Capacitor C14 ground connection；
Resistance RB2 connects with the cathode of resistance RB3, resistance RB5 and zener diode DW2 respectively；
Resistance RB3 and resistance RB4 connect；
Resistance RB4 is grounded after connecting with capacitor C14；
The anode of zener diode DW2 is connected with the base stage of resistance R21 and triode Q2 respectively；
Resistance R21 ground connection；The emitter of triode Q2 is grounded；
The collector of triode Q2 distinguishes connecting resistance R22 and resistance R23；
The base stage of resistance R23 difference connecting resistance R24 and triode Q3；
Resistance R24 ground connection, the emitter ground connection of triode Q3；
The collector of triode Q3 distinguishes the cathode of connecting resistance R25, resistance R26, the cathode of diode D9, diode D10
With the cathode of diode D11；
The anode of diode D9 connects with first voltage control signal VA；
The anode of diode D10 connects with second voltage control signal VB；
The anode of diode D11 connects with an output voltage control end VC；
Resistance R26 connects the cathode of zener diode DW3 and the base stage of triode Q4 respectively；
The plus earth of zener diode DW3；
The emitter of triode Q4 meets input undervoltage control terminal Vdown0 and R29 respectively；
The collector of triode Q4 is connected by resistance R28 with resistance R27；
Resistance RB6 meets capacitor C15, resistance R29, the cathode of zener diode DW4 and output voltage control end VC respectively；
The plus earth of capacitor C15 and zener diode DW4.
Wherein, the input overcurrent protection circuit includes the first DC voltage input end V1；
First DC voltage input end V1 respectively with resistance R30, resistance RA1, resistance RA2, resistance RA3, resistance RA4, electricity
Resistance R32, capacitor C18, resistance R34 are connected with the emitter of triode Q6；
Resistance R30 successively connects with the cathode of capacitor C16, resistance R41 and diode D14；
The anode of diode D14 connects with the collector of one end of resistance R42 and triode Q6 respectively；
The other end of resistance R42 takes over stream end Imax；
Resistance RA1, resistance RA2, resistance RA3 and resistance RA4 it is parallel with one another after, respectively with the cathode of diode D12, resistance
R31, the emitter of triode Q5 and connected by one end of the shunt circuit formed resistance RA5, resistance RA6, RA7；
By the other end of the shunt circuit formed resistance RA5, resistance RA6, RA7, difference resistance RA8, resistance R40, pressure stabilizing
The cathode of diode DW7 and the source electrode of switching tube M2 connect；
The anode of diode D12 connects with the base stage of one end of capacitor C17 and triode Q5 respectively；
The base stage of triode Q5 also connects with resistance R31；
The collector of triode Q5 connects with the cathode of resistance RA9 and zener diode DW6 respectively；
The anode of zener diode DW6 meets the anode of a zener diode DW5, resistance R38 and resistance R39 respectively；
The other end of resistance R38 and resistance R39 connect with the collector of triode Q7；
The other end of capacitor C17 distinguishes connecting resistance R32 and resistance R33, and resistance R33 passes through a diode D13 and three poles
The collector of pipe Q7 connects；
The cathode of zener diode DW5 connects with the base stage of resistance R34, capacitor C18 and triode Q6 respectively；
The base stage of triode Q7 connects with resistance R36 and resistance R37 respectively；
Resistance R37 connects a connecting terminal P5 and ground connection respectively；
The emitter of triode Q7 is grounded；
Resistance R36 locks protection control terminal Vdown1 respectively and connects, and passes through resistance R35 and input undervoltage control terminal
Vdown0 connects；
The grid of switching tube M2 is separately connected the anode and electricity of resistance R40, resistance R41, capacitor C16 and diode DW7
Hinder R43；
Resistance R43 connects with the collector of triode Q7；
The drain electrode of switching tube M2 is connected with one end of the cathode of diode D15, one end of inductance L1 and resistance R44 respectively
The other end of the anode of diode D15, the other end of inductance L1 and resistance R44 is inputted with the second DC voltage simultaneously
Hold V2.
Wherein, the output is under-voltage and overvoltage crowbar includes first part's circuit and second part circuit, in which:
First part's circuit includes first voltage control signal VA, second voltage control signal VB and locking protection control
End Vdown1 processed；
First voltage control signal VA is connected by the emitter of a diode D16 and triode Q8；
Second voltage control signal VB is connected by the emitter of a diode D17 and triode Q8；
Locking protection control terminal Vdown1 is connected by the emitter of a diode D18 and triode Q8；
The emitter of triode Q8 also distinguishes connecting resistance R45, R46 and capacitor C19；
Resistance R46 connects with output voltage control end VC；
The base stage of triode Q8 connects with resistance R45, the collector of capacitor C19 and triode Q9, resistance R47 respectively；
Resistance R47 connects with the end VP；
The collector of triode Q8 connects with the base stage of capacitor C20, resistance R48 and triode Q9 respectively；
Capacitor C20 and resistance R48 are grounded respectively；
The emitter of triode Q9 is grounded；
Second part circuit include output feedback voltage end U0, the output feedback voltage end U0 successively connecting resistance R49 with
Resistance R50, the anode of resistance R50 difference the connecting resistance R51 and diode D22；
The anode of resistance R51 difference connecting resistance R52 and diode D23；
Resistance 52 is grounded；
The cathode of diode D22 connects 6 pins of capacitor C22 and comparator U2_B respectively；
Capacitor C22 ground connection；
The cathode of diode D23 connects 2 pins of capacitor C23, the cathode of diode D19 and comparator U2_A respectively；
The anode of diode D19 connects the cathode of capacitor C24, resistance R55, resistance R56 and diode D20 respectively；
Resistance R57 is connected between resistance R55 and resistance R56；
Capacitor C24 and resistance R55 ground connection；
Resistance R56 connects the anode and overcurrent end Imax of diode D21 respectively；
The pin 5 of comparator U2_B meets 3 pins, capacitor C21, resistance R53 and the resistance RC1 of comparator U2_A respectively；
Capacitor C21 and resistance R53 ground connection；
Resistance RC1 connects with resistance RC2, resistance RC2 respectively with resistance R54,8 pins of comparator U2_A, diode D21
Cathode and output voltage control end VC connect；
Resistance R54 connects with the anode of 7 pins of comparator U2_B and diode D20 respectively
4 pins of comparator U2_B are grounded；
1 pin of comparator U2_A connects with the end VP.
By the above technical solution provided by the invention as it can be seen that the present invention provides a kind of transformation for DC to DC
Device, the protection circuit function having is comprehensive, can be realized input undervoltage protection, input overcurrent protection, output under-voltage protection and
Output over-voltage protection, it is simple and reasonable, the common devices such as resistance, capacitor, diode, voltage-stabiliser tube, triode, comparator are used only
Various defencive functions, manufacturing cost relative moderate can be realized in part, and good reliability is conducive to circuit protection, are conducive to extensive life
It produces and popularizes, be of great practical significance.
Detailed description of the invention
Fig. 1 is the schematic diagram of main circuit in a kind of converter for DC to DC provided by the invention；
Fig. 2 is the signal of input undervoltage protection circuit in a kind of converter for DC to DC provided by the invention
Figure；
Fig. 3 is the signal of input overcurrent protection circuit in a kind of converter for DC to DC provided by the invention
Figure；
Fig. 4 is that under-voltage and overvoltage crowbar the is exported in a kind of converter for DC to DC provided by the invention
The schematic diagram of a part；
Fig. 5 is that under-voltage and overvoltage crowbar the is exported in a kind of converter for DC to DC provided by the invention
The schematic diagram of two parts.
Specific embodiment
In order to enable those skilled in the art to better understand the solution of the present invention, with reference to the accompanying drawing with embodiment to this
Invention is described in further detail.
Referring to Fig. 1 to Fig. 5, the present invention provides a kind of converter for DC to DC, including main circuit, being used for will
The DC voltage inputted, after being boosted or being depressured, output (loads) to external electric equipment；
The main circuit, respectively with input undervoltage protection circuit, input overcurrent protection circuit, export under-voltage and overvoltage protection
Circuit is connected；
Wherein, input undervoltage protection circuit, for carrying out input undervoltage protection to main circuit；
Input overcurrent protection circuit, for carrying out input overcurrent protection to main circuit；
Under-voltage and overvoltage crowbar is exported for carrying out exporting under-voltage and output over-voltage protection to main circuit.
In the present invention, in specific implementation, referring to Fig. 1, the main circuit includes: pulse width modulation (PWM) chip IC；
1 pin of the pulse width modulation chip IC is connected with first voltage control signal VA；
2 pins of pulse width modulation chip IC respectively with capacitor C2, resistance R5, resistance R2, resistance R3 and resistance
R4 is connected；
Capacitor C2 is connected with first voltage control signal VA；
Resistance R5 is connected by capacitor C3 with first voltage control signal VA；
Ground connection after resistance R3 and resistance R4 is parallel with one another；
Resistance R2 connects with resistance R1；
Resistance R1 is connected with an output feedback voltage end U0 respectively；
The output feedback voltage end U0 connects with the anode of diode D1, the cathode of diode D1 connect respectively capacitor C1 and
The cathode of diode D2；
It should be noted that in the present invention, the cathode of the diode D1 can also be connected with a vdd terminal, VDD
End is a label in main circuit, for indicating the working power current potential of pulse width modulation chip IC, for testing.
Capacitor C1 ground connection, the anode of diode D2 connect with the emitter of a triode Q1；
The base stage of triode Q1 respectively with the cathode of zener diode DW1, resistance R7 and second voltage control signal VB
Connect；
The plus earth of zener diode DW1；
The collector of triode Q1 connects with resistance R6；
Resistance R6 and resistance R7 confluence after, respectively with resistance R11, capacitor C7, resistance R18, capacitor C8, the second DC voltage
The voltage input-terminal 1 of input terminal V2 and transformer T1 connects；
Resistance R11 and capacitor C7 also connect with the cathode of diode D5, and the anode of diode D5 passes through a resistance R12 points
Do not connect with the drain electrode of the voltage input-terminal 2 of transformer T1 and a switching tube M1；
The source electrode of switching tube M1 connects with resistance R16 and resistance R17 respectively, resistance R16 and resistance R17 ground connection；
The grid of switching tube M1 connects with resistance R14, the anode of diode D4 and resistance R15 respectively；
Resistance R15 connects with resistance R16；
6 pins of pulse width modulation chip IC respectively with the cathode of diode D3, resistance R14 and resistance R13 phase
It connects, resistance R13 connects with the cathode of diode D4；
The 5 pins ground connection of the pulse width modulation chip IC；
7 pins of the pulse width modulation chip IC connect with the cathode of the diode D1；
8 pins and capacitor C6 of the pulse width modulation chip IC connect；Capacitor C6 ground connection；
It should be noted that in the present invention, 8 pins of the pulse width modulation chip IC can also be with a Vref
End is connected, and the end Vref is a label in main circuit, for indicating that 8 pins of pulse width modulation chip IC are conducts
The end vref uses, for testing.
3 pins of the pulse width modulation chip IC connect with capacitor C4 and resistance R10 respectively；Capacitor C4 ground connection；
Resistance R10 connects with resistance R15 and resistance R16 respectively；
4 pins of the pulse width modulation chip IC connect with capacitor C5 and resistance R8, resistance R9 respectively；Capacitor C5 connects
Connect after ground, the resistance R8 and resistance R9 parallel connection in capacitor C6；
The output feedback voltage end U0 also connects with the cathode of one end of capacitor C10 and diode D6 respectively；
The anode of diode D6 connects with the output voltage terminals 6 of transformer T1, the other end of capacitor C10 respectively with transformation
The output voltage terminals 5 of device T1 connect and are grounded；
It is parallel with capacitor C11 and capacitor C12 respectively between the output voltage terminals 3 and output voltage terminals 4 of transformer T1,
One end of the capacitor C12 is grounded；
It should be noted that in the present invention, the C12 of the capacitor can also be connected with an end U00, and the end U00 exists
It is a label in main circuit, first via output voltage is used for, for testing.
Capacitor C13 is parallel between the output voltage terminals 7 and output voltage terminals 8 of transformer T1, the capacitor C13's
One end ground connection.
It should be noted that in the present invention, the C13 of the capacitor can also be connected with an end U01, and the end U01 exists
It is a label in main circuit, the second road output voltage is used for, for testing.
In specific implementation, switching tube M1 is NMOS fet switch.
It should be noted that NMOS fet switchs, grid high level (VGS > Vt) conducting, low level is broken
It opens, can be used to control the conducting between ground.
In specific implementation, the both ends of the capacitor C12 are parallel with connecting terminal P1 and connecting terminal P2；
The both ends of the capacitor C13 are parallel with connecting terminal P3 and connecting terminal P4.Therefore, the present invention can easily to
The electrical equipment (such as mobile phone, tablet computer) of outside need direct current supply exports supply voltage.
In specific implementation, transformer T1 further includes that the voltage that is made of output voltage terminals 9 and output voltage terminals 10 is defeated
Group out, and the voltage output group being made of output voltage terminals 11 and output voltage terminals 12, as two groups of voltage output ends.
In specific implementation, described pulse width modulation (PWM) chip IC can be raw by Texas Instruments company
The Current Control Mode PWM Switched controller chip UC1845 of production, the chip circuit switching frequency is adjustable, has current feedback and voltage
The characteristics of feeding back double -loop control,
It should be noted that each pin function of UC1845 chip is as follows:
1 pin is error amplifier output, is used for loop compensation, and chip does not work when low level, can be used as protection end；
2 pins are the anti-phase inputs of error amplifier, are connected to Switching Power Supply output, starting voltage by a resitstance voltage divider
Feedback effect, adjusts the duty ratio of output, to stabilize the output voltage；
3 pins are current sampling pin, the conducting that pulse width modulator is switched using the output of this end-of-message；
4 pins, by time resistance RT, are connected to and are connected to reference to output pin 8 and time capacitor CT for timing
Ground keeps oscillator frequency and maximum output duty ratio adjustable；
5 pins be control circuit and power supply publicly；
6 pins are the square wave pins of output driving switching tube, can directly drive the grid of power tube MOSFET；
7 pins are the positive supplies (VCC) for controlling integrated circuit, are suitble to driving MOSFET and suitable for middle low power
DC/DC Switching Power Supply；
8 pins are that internal reference voltage source generates 5.0V reference voltage, can be used as the electricity of outside circuit output 5V/50mA
Source provides charging current to capacitor CT by resistance RT.
Therefore, above scheme is based on it is found that the main circuit has the isolation of four tunnels and stable output electricity for the present invention
Pressure.
In the present invention, in specific implementation, referring to fig. 2, the input undervoltage protection circuit includes that the first DC voltage is defeated
Enter to hold V1；
First DC voltage input end V1 is connected with resistance RB1, resistance R22, resistance R25 and resistance R27 respectively；
Resistance RB1 connects with capacitor C14 and resistance RB2 respectively；Capacitor C14 ground connection；
Resistance RB2 connects with the cathode of resistance RB3, resistance RB5 and zener diode DW2 respectively；
Resistance RB3 and resistance RB4 connect；
Resistance RB4 is grounded after connecting with capacitor C14；
The anode of zener diode DW2 is connected with the base stage of resistance R21 and triode Q2 respectively；
Resistance R21 ground connection；The emitter of triode Q2 is grounded；
The collector of triode Q2 distinguishes connecting resistance R22 and resistance R23；
The base stage of resistance R23 difference connecting resistance R24 and triode Q3；
Resistance R24 ground connection, the emitter ground connection of triode Q3；
The collector of triode Q3 distinguishes the cathode of connecting resistance R25, resistance R26, the cathode of diode D9, diode D10
With the cathode of diode D11；
The anode of diode D9 connects with first voltage control signal VA, and (i.e. the first voltage of main circuit controls in Fig. 1
Input terminal VA)；
The anode of diode D10 connects with second voltage control signal VB, and (i.e. the second voltage of main circuit controls in Fig. 1
Input terminal VB)；
The anode of diode D11 connects with an output voltage control end VC (i.e. exports under-voltage and overvoltage protection electricity in Fig. 5
Output voltage control end VC shown in road, for being powered to the under-voltage and overvoltage crowbar of output)；
Resistance R26 connects the cathode of zener diode DW3 and the base stage of triode Q4 respectively；
The plus earth of zener diode DW3；
The emitter of triode Q4 meets input undervoltage control terminal Vdown0 and R29 respectively；
It should be noted that the end Vdown0 is input undervoltage control terminal, when input undervoltage protection, low electricity can be set to
Flat and Fig. 3 input overcurrent protection circuit is associated.
The collector of triode Q4 is connected by resistance R28 with resistance R27；
Resistance RB6 meets capacitor C15, resistance R29, the cathode of zener diode DW4 and output voltage control end VC respectively；
The plus earth of capacitor C15 and zener diode DW4.
It should be noted that the first DC voltage input end V1 is used to input external DC voltage (i.e. external dc electricity
The output voltage in source), the voltage of port is provided by external dc power (can be any one existing DC power supply)
Input voltage.
In the present invention, in specific implementation, referring to Fig. 3, the input overcurrent protection circuit includes that the first DC voltage is defeated
Enter to hold V1；First DC voltage input end V1 connection, one connecting terminal P；
First DC voltage input end V1 respectively with resistance R30, resistance RA1, resistance RA2, resistance RA3, resistance RA4, electricity
Resistance R32, capacitor C18, resistance R34 are connected with the emitter of triode Q6 (positive-negative-positive)；
Resistance R30 successively connects with the cathode of capacitor C16, resistance R41 and diode D14；
The anode of diode D14 connects with the collector of one end of resistance R42 and triode Q6 (positive-negative-positive) respectively；
The other end of resistance R42 takes over stream end Imax；
It should be noted that the end Imax is overcurrent end, when input current overcurrent, Q6 enters amplification region, and Imax will increase,
It is associated to trigger second part circuit in the input undervoltage and overvoltage crowbar of current-limiting protection circuit movement and Fig. 5.
Resistance RA1, resistance RA2, resistance RA3 and resistance RA4 it is parallel with one another after, respectively with the cathode of diode D12, resistance
R31, the emitter of triode Q5 and connected by one end of the shunt circuit formed resistance RA5, resistance RA6, RA7；
By the other end of the shunt circuit formed resistance RA5, resistance RA6, RA7, difference resistance RA8, resistance R40, pressure stabilizing
The cathode of diode DW7 and the source electrode of switching tube M2 connect；
The anode of diode D12 connects with the base stage of one end of capacitor C17 and triode Q5 respectively；
The base stage of triode Q5 also connects with resistance R31；
The collector of triode Q5 connects with the cathode of resistance RA9 and zener diode DW6 respectively；
The anode of zener diode DW6 meets the anode of a zener diode DW5, resistance R38 and resistance R39 respectively；
The other end of resistance R38 and resistance R39 connect with the collector of triode Q7；
The other end of capacitor C17 distinguishes connecting resistance R32 and resistance R33, and resistance R33 passes through a diode D13 and three poles
The collector of pipe Q7 connects；
The cathode of zener diode DW5 connects with the base stage of resistance R34, capacitor C18 and triode Q6 (positive-negative-positive) respectively；
The base stage of triode Q7 connects with resistance R36 and resistance R37 respectively；
Resistance R37 meets a connecting terminal P5 and ground connection l respectively
The emitter of triode Q7 is grounded；
Resistance R36 locks protection control terminal Vdown1 respectively and connects, and passes through resistance R35 and input undervoltage control terminal
Vdown0 connects；
It should be noted that the end Vdown1 is locked out protection control terminal, when lock out action occurs, low electricity can be set to
First part's circuit is associated in flat and the input undervoltage and overvoltage crowbar of Fig. 4.
The grid of switching tube M2 is separately connected the anode and electricity of resistance R40, resistance R41, capacitor C16 and diode DW7
Hinder R43；
Resistance R43 connects with the collector of triode Q7；
The drain electrode of switching tube M2 is connected with one end of the cathode of diode D15, one end of inductance L1 and resistance R44 respectively
The other end of the anode of diode D15, the other end of inductance L1 and resistance R44 is inputted with the second DC voltage simultaneously
It holds V2 (i.e. the second DC voltage input end V2 of main circuit in Fig. 1).
It should be noted that the first DC voltage input end V1 is used to input external DC voltage (i.e. external dc electricity
The output voltage in source), the voltage of port is provided by external dc power (can be any one existing DC power supply)
Input voltage.
It should be noted that for the present invention, input undervoltage protection circuit and input overcurrent protection circuit are arranged in master
Two transition circuits between circuit and external dc power each serve as the work of input undervoltage protection and input overcurrent protection
With.
In the present invention, in specific implementation, referring to fig. 4 and Fig. 5, the output is under-voltage and overvoltage crowbar includes first
Partial circuit and second part circuit, in which:
First part's circuit includes first voltage control signal VA, second voltage control signal VB and locking protection control
End Vdown1 processed；
First voltage control signal VA is connected by the emitter of a diode D16 and triode Q8；
Second voltage control signal VB is connected by the emitter of a diode D17 and triode Q8；
Locking protection control terminal Vdown1 is connected by the emitter of a diode D18 and triode Q8；
The emitter of triode Q8 also distinguishes connecting resistance R45, R46 and capacitor C19；
Resistance R46 connects with output voltage control end VC；
The base stage of triode Q8 connects with resistance R45, the collector of capacitor C19 and triode Q9, resistance R47 respectively；
Resistance R47 connects with under-voltage and output over-voltage protection control terminal VP is exported；
It should be noted that the end VP is to export under-voltage and output over-voltage protection control terminal, when output is under-voltage or exports
When pressure, the end VP is that second part circuit is associated in the input undervoltage and overvoltage crowbar of low level and Fig. 5.
The collector of triode Q8 connects with the base stage of capacitor C20, resistance R48 and triode Q9 respectively；
Capacitor C20 and resistance R48 are grounded respectively；
The emitter of triode Q9 is grounded.
Second part circuit include output feedback voltage end U0, the output feedback voltage end U0 successively connecting resistance R49 with
Resistance R50, the anode of resistance R50 difference the connecting resistance R51 and diode D22；
The anode of resistance R51 difference connecting resistance R52 and diode D23；
Resistance 52 is grounded；
The cathode of diode D22 connects 6 pins of capacitor C22 and comparator U2_B respectively；
Capacitor C22 ground connection；
The cathode of diode D23 connects 2 pins of capacitor C23, the cathode of diode D19 and comparator U2_A respectively；
The anode of diode D19 connects the cathode of capacitor C24, resistance R55, resistance R56 and diode D20 respectively；
Resistance R57 is connected between resistance R55 and resistance R56；
Capacitor C24 and resistance R55 ground connection；
Resistance R56 connects the anode and overcurrent end Imax of diode D21 respectively；
The pin 5 of comparator U2_B meets 3 pins, capacitor C21, resistance R53 and the resistance RC1 of comparator U2_A respectively；
Capacitor C21 and resistance R53 ground connection；
Resistance RC1 connects with resistance RC2, resistance RC2 respectively with resistance R54,8 pins of comparator U2_A, diode D21
Cathode and output voltage control end VC connect；
Resistance R54 connects with the anode of 7 pins of comparator U2_B and diode D20 respectively
4 pins of comparator U2_B are grounded；
1 pin of comparator U2_A connects with under-voltage and output over-voltage protection control terminal VP is exported, i.e. first part's circuit
In output is under-voltage and output over-voltage protection control terminal VP.
It should be noted that in the present invention, in specific implementation, the comparator U2_A and comparator U2_B be can be together
One chip provides two groups of voltage comparators, 1~3 one group of pin, 5~7 one group of pins, wherein 1 pin is first group of voltage
Comparator output terminal, 2 pins are first group of voltage comparator reverse input end, and 3 pins are that first group of voltage comparator forward direction is defeated
Enter end, 7 pins are second group of voltage comparator output end, and 6 pins are second group of voltage comparator reverse input end, and 5 pins are
Second group of voltage comparator positive input, 8 pins are power supply, 4 pins ground connection.
In the present invention, for input undervoltage protection circuit.Input terminal input voltage, input terminal are protected with input undervoltage
Function avoids the brownout due to input terminal, and converter (DC-DC converter) main circuit is caused to be in abnormal work shape
State.Setting " protection initiation value " and " protection return value ", if the input voltage of converter reaches " protection return value ", converter
(DC-DC converter) main circuit starts to work normally；Meanwhile " protection starts if input voltage is dropped to by " protection return value "
When value ", converter can then stop working.After input undervoltage protection circuit is triggered, converter (DC-DC converter) main circuit
It stops working, when input voltage restores to when " protection return value ", converter (DC-DC converter) main circuit can restore automatically
Work, input undervoltage protection circuit do not have protection lock function.
In the present invention, for input overcurrent protection circuit.In start process, input terminal has two sections of current-limiting protection function
Can, effectively avoid the surge impact of input terminal.If short circuit occurs for converter (DC-DC converter) main circuit or input current is different
It is often excessive, input current, and delay cutoff input current can be limited.Certain time, (this time can use component after booting
Parameter adjustment) in, one section of cut-off current works, and one section of cut-off current is adjustable.After one section of current limliting, two sections of cut-off currents work, and two
Section cut-off current increases with input voltage and is reduced.When converter (DC-DC converter) main circuit works normally, current-limiting function is not
Starting, when overcurrent occurs, current-limiting function starting, persistently working certain time in current-limiting function, (this time can use first device
The adjustment of part parameter) after, it protects circuit operation and locks, i.e., it can only be by restarting circuit ability de-preservation state.
In the present invention, under-voltage for output voltage and overvoltage crowbar.When converter (DC-DC converter) main electricity
The output voltage on road is higher than " output over-voltage protection action value ", and output over-voltage protection starts and locks；When (DC-DC becomes converter
Parallel operation) main circuit output voltage lower than " output under-voltage protection action value ", output under-voltage protection starts and locks.
It should be noted that purpose of design is to realize DC to DC for the present invention, and by examining, input electricity
Pressing range is 21V~50V, and under normal circumstances, input voltage is exported in 42V or so as 13V, when input voltage is lower than 21V
When, input undervoltage protection circuit movement, i.e. " protection initiation value " they are 21V, and " protection return value " is 24V；When output voltage is higher than
When 19V, output overvoltage protection circuit movement, when output voltage is lower than 9V, output under-voltage protecting circuit movement, while having two
Section current-limiting protection function, one section of cut-off current is 400mA, and two sections of current limlitings are reduced, 20V pairs of input voltage with the increase of input voltage
Answering two sections of cut-off currents is 225mA, and the corresponding two sections of cut-off currents of input voltage 50V are 90mA.Specific circuit solutions are as follows:
As shown in Figure 1, the core devices of main circuit are UC1845 chips, pin 1 is protection end, when the pin level is drawn
Chip does not work when low；Feedback voltage is input to pin 2 after resistance (R1~R4) partial pressure, as the benchmark electricity for generating PWM wave
Pressure.Pin 3 inputs a sampling voltage, and pulsewidth debugger controls the conducting of output switch with this information；Pin 4 is that crystal oscillator is defeated
Enter, resistance be connected to Vref and capacitance connection to ground, generates oscillator signal, R9 is adjustable resistance, make oscillator frequency and
Maximum output duty ratio is adjustable；Pin 5 is publicly；Pin 6 is chip output, directly drives MOSFET tube grid；Pin 7 is
Chip operation power supply, when beginning, are first powered by input power, and after generating output voltage, the voltage using output end is chip
UC1845 power supply；The 5V voltage Vref of 8 outputting standard of pin provides charging current to capacitor by resistance, crystal oscillator is made to work.
As shown in Figure 1, main circuit mainly includes the portions such as filter module, power supply module, switching tube drive module, output module
Point.V2 be main circuit input power (approximately uniform with the V1 in Fig. 2), by R18, R19, C8, C9 form filter module,
It is provided operating voltage (into pin 7) by Q1 for chip, filter module selects the mode of RC low-pass filter circuit to eliminate high frequency
Interference of the signal to Switching Power Supply.For power supply module, since the effect of DW1 makes the base stage of Q1 be fixed on 11V, after Q1 conducting
The cathode of D2 is approximately under 9.6V current potential, and after chip works normally, feedback voltage 13V (transformer 5,6 ends) is after D1
Current potential is higher than 9.6V, will replace input voltage, is powered to chip, to realize self-powered.The drive of switching tube drive module
Dynamic signal, 6 feet (OUT terminal) from UC1845 export a pwm signal, thus maximum value VCC, minimum value 0V drive
Dynamic N-MOS's opening and turning off.That is, its grid voltage is greater than source electrode when the voltage of the output end of UC1845 is VCC
Voltage, then switching tube is connected；When the voltage of the output end of UC1845 is 0V, its grid voltage is not more than source voltage, then switchs
Pipe shutdown, and the duty ratio of PWM is determined by the feedback signal of circuit.Output module specially reserves all the way as feedback winding；For
Reduce distribution capacity, choose the thicker conducting wire of insulated hull, the dielectric constant of insulated hull wants small；For reduce leakage inductance, by primary side winding,
Main isolation output winding, three line of feedback winding and around, three line of excess-three winding and around.
It is external dc power (can be existing as shown in Fig. 2, the input voltage of the first DC voltage input end V1
Any one DC power supply) provided by input voltage, when input voltage reaches for the first time " protection return value ", zener diode
DW2 ability reverse breakdown, Q2 is connected at this time, Q3 shutdown, DW3 reverse breakdown, Q4 conducting, thus DW4 ability reverse breakdown, formation
The output voltage of output voltage terminal VC, power supply electricity of the output voltage of output voltage control end VC as comparator circuit in Fig. 5
Pressure makes Fig. 4 and the output of Fig. 5 (Fig. 4 is connected with the circuit of Fig. 5) under-voltage and overvoltage crowbar work.RB1~RB6 herein
For adjustable resistance, available different " protection return value " is worth by the choosing to a little debugging resistance.
After circuit works normally, if input voltage is lower than " protection initiation value ", Q2 shutdown, Q3 conducting, Q4 shutdown.By
In the conducting of Q3, make the current potential of first voltage control signal VA, second voltage control signal VB, output voltage control end VC
It is pulled low, VA, VB, VC are three critical control point in converter circuit of the invention, wherein first voltage control signal
No. 1 pin of UC1845 chip is directly set to low level, UC1845 chip is made not work (see the VA in Fig. 1) by VA；Second electricity
Pressure control signal VB prevents Q1 from being smoothly connected, and 7 pins of UC1845 chip is made to cannot get the voltage of input power (see Fig. 1
In VB)；The output voltage that output voltage control end VC is provided, is the working power of comparator circuit in Fig. 5.If these three point
It is low level, then entire converter is in off working state.
As shown in figure 3, the first DC voltage input end V1 is input voltage, when circuit powers on, capacitor C17 is uncharged,
Q5 is connected at this time, if triggering current-limiting protection circuit movement, triode Q6 is needed to be in non-off state, output current limiting control letter
Number Imax.Specific: the branch of " equivalent resistance-Q5-DW6 of RA1~RA4 " and the branch voltage of " Q6-DW5 " should phases
Together, therefore meet following formula:
Ilim1×RIt is equivalent+VDW6=VD+VDW5；
Wherein, Ilim1For one section of cut-off current, RIt is equivalentFor the equivalent resistance of RA1~RA4, VDW6For zener diode DW6's
Voltage value, VDThe tube voltage drop between the EB of Q6, VDW5For the voltage value of zener diode DW5.
In formula, only Ilim1For unknown number, other parameters can according to need and be adjusted.When input current is greater than
Ilim1When, Q6 can then enter amplification region, and the electric current of Imax will increase, that is, increase trigger signal, and triggering current-limiting protection circuit is dynamic
Make, therefore reaches one section of current limitation effect.
After capacitor C17 charging complete, the upper end C17 is high level, and Q5 ends at this time, if triggering current-limiting protection circuit is dynamic
Make, also needs triode Q6 and be in non-off state, output current limiting controls signal Imax.Specific: " RA1~RA4's is equivalent
The branch voltage of resistance-RA5~RA7 equivalent resistance-RA8~RA9 equivalent resistance-DW6 " branch and " Q6-DW5 "
Should be identical, therefore two branches meet following formula:
Ilim2×(REquivalent 1+REquivalent 2+REquivalent 3)+VDW6=VD+VDW5；
Wherein, Ilim2For two sections of cut-off currents, REquivalent 1For the equivalent resistance of RA1~RA4, REquivalent 2For the equivalent of RA5~RA7
Resistance value, REquivalent 3For the equivalent resistance of RA8~RA9, VDW6For the voltage value of zener diode DW6, VDThe pipe pressure between the EB of Q6
Drop, VDW5For the voltage value of zener diode DW5.
At this point, in formula, only Ilim2For unknown number, other parameters can according to need and be adjusted.When input electricity
Stream is greater than Ilim2When, Q6 can then enter amplification region, and the electric current of Imax will increase, that is, increase trigger signal, trigger current-limiting protection
Circuit operation, therefore reach two sections of current limitation effects.Meanwhile as shown from the above formula, Ilim2< Ilim1, that is to say, that when circuit opens
One section of cut-off current of setting protects circuit when dynamic, and two sections of cut-off currents of setting protect circuit when circuit works normally
Shield, therefore reduce the malfunction rate of current-limiting protection circuit.
In addition, as shown in figure 3, DW7 will obtain in this way voltage V2, as so that M2 is often connected when circuit works normally
Input voltage in Fig. 1.When Vdown0 and Vdown1 be low level, cause Q7 to end, the G of switching tube M2 extremely high level, M2
Shutdown, V2 cannot get voltage, and DC-DC can not work normally.Vdown0 can make from Fig. 2 when input undervoltage protection act
Vdown0 is set to low level, and Vdown1 can make Vdown1 be set to low level from Fig. 4 when lock out action occurs, that is,
It says when any one protection act, can all lead to V2 power loss.
As shown in Figure 4, Figure 5, Fig. 4 is protection lock-in circuit, and Fig. 5 is comparator circuit.It is protected for exporting under-voltage and over-voltage
Protection circuit, U0 are to export feedback voltage (13V) to respectively enter the negative terminal of comparator by the partial pressure of R49~R52, comparator
Anode is reference voltage, from VC by the partial pressure of RC1 (adjustable resistance), RC2 (adjustable resistance) and R53, this circuit design
For 2.5V, when output voltage over-voltage, the voltage of 2 pins of comparator U2_A will be greater than reference voltage, and U2_A exports low level, VP
For low level；When output voltage is under-voltage, the voltage of 6 pins of U2_B will be less than reference voltage, and U2_B exports high level, pass through
D20, D19 return to 2 pins of U2_A, and the high potential of comparator will be greater than reference voltage at this time, and U2_A exports low level, and VP is low
Level；
For input overcurrent protection circuit, Imax can make the voltage increase of 2 pins of U2_A by the charging of C24, when big
U2_A can be equally set to export low level when reference voltage, VP is low level.That is no matter output voltage be over-voltage or
It is under-voltage, and input overcurrent, all will lead to VP is low level.
When VC and VP is high level, Q8 and Q9 are not turned on, and VA, VB, Vdowm1 are high potentials；It is locked when circuit triggers
When protecting surely, VP is low level, and Q8 and Q9 are connected, and at this moment VA, VB, Vdowm1 are pulled low, thus flip chip protection, cutting
Chip power plays a protective role.
Based on above technical scheme it is found that for converter provided by the invention, main circuit using UC1845 chip and
MOSFET and subsidiary components realize DC to DC, have control, protection, detection function, steady operation may be implemented
Self-powered afterwards improves efficiency, while the output of four ends at most may be implemented.
Meanwhile for the present invention, the protection circuit function having is comprehensive, and input undervoltage protection may be implemented, inputted
Stream protection, output under-voltage protection and output over-voltage protection, are used only resistance, capacitor, diode, voltage-stabiliser tube, triode, comparator
Various defencive functions can be realized etc. common device, therefore greatly reduce the cost for inputting circuit under proteciton, and facilitate debugging,
Improve the reliability of circuit.Input undervoltage protection circuit passes through three by setting " protection initiation value " and " protection return value "
The on-off of a core triode realizes defencive function.First cut-off current is arranged in input overcurrent protection circuit when circuit start
Circuit is protected, and when circuit works normally, second cut-off current of setting protects circuit, therefore, reduces
The malfunction rate of stream protection circuit.The present invention can be also used for experimental real-training teaching, especially to electronic technology, circuit theory,
The courses such as power electronics tool has significant practical applications.
By the above technical solution provided by the invention as it can be seen that the present invention provides a kind of transformation for DC to DC
Device, the protection circuit function having is comprehensive, can be realized input undervoltage protection, input overcurrent protection, output under-voltage protection and
Output over-voltage protection, it is simple and reasonable, the common devices such as resistance, capacitor, diode, voltage-stabiliser tube, triode, comparator are used only
Various defencive functions, manufacturing cost relative moderate can be realized in part, and good reliability is conducive to circuit protection, are conducive to extensive life
It produces and popularizes, be of great practical significance.
The above is only a preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications are also answered
It is considered as protection scope of the present invention.
Claims (7)
1. a kind of converter for DC to DC, which is characterized in that the direct current including main circuit, for will be inputted
Pressure after being boosted or being depressured, is exported to external electric equipment；
The main circuit, respectively with input undervoltage protection circuit, input overcurrent protection circuit, export under-voltage and overvoltage crowbar
It is connected；
Wherein, input undervoltage protection circuit, for carrying out input undervoltage protection to main circuit；
Input overcurrent protection circuit, for carrying out input overcurrent protection to main circuit；
Under-voltage and overvoltage crowbar is exported for carrying out exporting under-voltage and output over-voltage protection to main circuit.
2. converter as described in claim 1, which is characterized in that the main circuit includes: pulse width modulation chip IC；
1 pin of the pulse width modulation chip IC is connected with first voltage control signal VA；
2 pins of pulse width modulation chip IC respectively with capacitor C2, resistance R5, resistance R2, resistance R3 and resistance R4 phase
Connection；
Capacitor C2 is connected with first voltage control signal VA；
Resistance R5 is connected by capacitor C3 with first voltage control signal VA；
Ground connection after resistance R3 and resistance R4 is parallel with one another；
Resistance R2 connects with resistance R1；
Resistance R1 is connected with an output feedback voltage end U0 respectively；
The output feedback voltage end U0 connects with the anode of diode D1, and the cathode of diode D1 meets capacitor C1 and two poles respectively
The cathode of pipe D2；
Capacitor C1 ground connection, the anode of diode D2 connect with the emitter of a triode Q1；
The base stage of triode Q1 connects with the cathode of zener diode DW1, resistance R7 and second voltage control signal VB respectively；
The plus earth of zener diode DW1；
The collector of triode Q1 connects with resistance R6；
After resistance R6 and resistance R7 confluence, inputted respectively with resistance R11, capacitor C7, resistance R18, capacitor C8, the second DC voltage
The voltage input-terminal 1 of end V2 and transformer T1 connects；
Resistance R11 and capacitor C7 also connect with the cathode of diode D5, the anode of diode D5 by a resistance R12 respectively with
The drain electrode of the voltage input-terminal 2 of transformer T1 and a switching tube M1 connects；
The source electrode of switching tube M1 connects with resistance R16 and resistance R17 respectively, resistance R16 and resistance R17 ground connection；
The grid of switching tube M1 connects with resistance R14, the anode of diode D4 and resistance R15 respectively；
Resistance R15 connects with resistance R16；
6 pins of the pulse width modulation chip IC connect with the cathode of diode D3, resistance R14 and resistance R13 respectively, electricity
Resistance R13 connects with the cathode of diode D4；
The 5 pins ground connection of the pulse width modulation chip IC；
7 pins of the pulse width modulation chip IC connect with the cathode of the diode D1；
8 pins and capacitor C6 of the pulse width modulation chip IC connect；Capacitor C6 ground connection；
3 pins of the pulse width modulation chip IC connect with capacitor C4 and resistance R10 respectively；Capacitor C4 ground connection；
Resistance R10 connects with resistance R15 and resistance R16 respectively；
4 pins of the pulse width modulation chip IC connect with capacitor C5 and resistance R8, resistance R9 respectively；Capacitor C5 ground connection,
Connect after the resistance R8 and resistance R9 are in parallel in capacitor C6；
The output feedback voltage end U0 also connects with the cathode of one end of capacitor C10 and diode D6 respectively；
The anode of diode D6 connects with the output voltage terminals 6 of transformer T1, the other end of capacitor C10 respectively with transformer T1
Output voltage terminals 5 connect and be grounded；
Capacitor C11 and capacitor C12 is parallel between the output voltage terminals 3 and output voltage terminals 4 of transformer T1 respectively, it is described
One end of capacitor C12 is grounded；
Capacitor C13, one end of the capacitor C13 are parallel between the output voltage terminals 7 and output voltage terminals 8 of transformer T1
Ground connection.
3. converter as claimed in claim 2, which is characterized in that the both ends of the capacitor C12 be parallel with connecting terminal P1 and
Connecting terminal P2；
The both ends of the capacitor C13 are parallel with connecting terminal P3 and connecting terminal P4.
4. converter as claimed in claim 2, which is characterized in that transformer T1 further includes by output voltage terminals 9 and voltage
The voltage output group that output terminal 10 forms, and the voltage output being made of output voltage terminals 11 and output voltage terminals 12
Group.
5. the converter as described in any one of claim 2 to 4, which is characterized in that the input undervoltage protection circuit includes
First DC voltage input end V1；
First DC voltage input end V1 is connected with resistance RB1, resistance R22, resistance R25 and resistance R27 respectively；
Resistance RB1 connects with capacitor C14 and resistance RB2 respectively；Capacitor C14 ground connection；
Resistance RB2 connects with the cathode of resistance RB3, resistance RB5 and zener diode DW2 respectively；
Resistance RB3 and resistance RB4 connect；
Resistance RB4 is grounded after connecting with capacitor C14；
The anode of zener diode DW2 is connected with the base stage of resistance R21 and triode Q2 respectively；
Resistance R21 ground connection；The emitter of triode Q2 is grounded；
The collector of triode Q2 distinguishes connecting resistance R22 and resistance R23；
The base stage of resistance R23 difference connecting resistance R24 and triode Q3；
Resistance R24 ground connection, the emitter ground connection of triode Q3；
The collector of triode Q3 distinguishes connecting resistance R25, resistance R26, the cathode of diode D9, the cathode of diode D10 and two
The cathode of pole pipe D11；
The anode of diode D9 connects with first voltage control signal VA；
The anode of diode D10 connects with second voltage control signal VB；
The anode of diode D11 connects with an output voltage control end VC；
Resistance R26 connects the cathode of zener diode DW3 and the base stage of triode Q4 respectively；
The plus earth of zener diode DW3；
The emitter of triode Q4 meets input undervoltage control terminal Vdown0 and R29 respectively；
The collector of triode Q4 is connected by resistance R28 with resistance R27；
Resistance RB6 meets capacitor C15, resistance R29, the cathode of zener diode DW4 and output voltage control end VC respectively；
The plus earth of capacitor C15 and zener diode DW4.
6. converter as claimed in claim 5, which is characterized in that the input overcurrent protection circuit includes the first DC voltage
Input terminal V1；
First DC voltage input end V1 respectively with resistance R30, resistance RA1, resistance RA2, resistance RA3, resistance RA4, resistance
R32, capacitor C18, resistance R34 are connected with the emitter of triode Q6；
Resistance R30 successively connects with the cathode of capacitor C16, resistance R41 and diode D14；
The anode of diode D14 connects with the collector of one end of resistance R42 and triode Q6 respectively；
The other end of resistance R42 takes over stream end Imax；
Resistance RA1, resistance RA2, resistance RA3 and resistance RA4 it is parallel with one another after, respectively with the cathode of diode D12, resistance R31,
The emitter of triode Q5 and connected by one end of the shunt circuit formed resistance RA5, resistance RA6, RA7；
By the other end of the shunt circuit formed resistance RA5, resistance RA6, RA7, difference resistance RA8, resistance R40, two pole of pressure stabilizing
The cathode of pipe DW7 and the source electrode of switching tube M2 connect；
The anode of diode D12 connects with the base stage of one end of capacitor C17 and triode Q5 respectively；
The base stage of triode Q5 also connects with resistance R31；
The collector of triode Q5 connects with the cathode of resistance RA9 and zener diode DW6 respectively；
The anode of zener diode DW6 meets the anode of a zener diode DW5, resistance R38 and resistance R39 respectively；
The other end of resistance R38 and resistance R39 connect with the collector of triode Q7；
The other end of capacitor C17 distinguishes connecting resistance R32 and resistance R33, and resistance R33 passes through a diode D13 and triode Q7
Collector connect；
The cathode of zener diode DW5 connects with the base stage of resistance R34, capacitor C18 and triode Q6 respectively；
The base stage of triode Q7 connects with resistance R36 and resistance R37 respectively；
Resistance R37 connects a connecting terminal P5 and ground connection respectively；
The emitter of triode Q7 is grounded；
Resistance R36 locks protection control terminal Vdown1 respectively and connects, and passes through resistance R35 and input undervoltage control terminal Vdown0
Connect；
The grid of switching tube M2 is separately connected the anode and resistance of resistance R40, resistance R41, capacitor C16 and diode DW7
R43；
Resistance R43 connects with the collector of triode Q7；
The drain electrode of switching tube M2 is connected with one end of the cathode of diode D15, one end of inductance L1 and resistance R44 respectively
The other end of the anode of diode D15, the other end of inductance L1 and resistance R44 simultaneously with the second DC voltage input end
V2。
7. converter as claimed in claim 6, which is characterized in that the output is under-voltage and overvoltage crowbar includes first
Parallel circuit and second part circuit, in which:
First part's circuit includes first voltage control signal VA, second voltage control signal VB and locking protection control terminal
Vdown1；
First voltage control signal VA is connected by the emitter of a diode D16 and triode Q8；
Second voltage control signal VB is connected by the emitter of a diode D17 and triode Q8；
Locking protection control terminal Vdown1 is connected by the emitter of a diode D18 and triode Q8；
The emitter of triode Q8 also distinguishes connecting resistance R45, R46 and capacitor C19；
Resistance R46 connects with output voltage control end VC；
The base stage of triode Q8 connects with resistance R45, the collector of capacitor C19 and triode Q9, resistance R47 respectively；
Resistance R47 connects with under-voltage and output over-voltage protection control terminal VP is exported；
The collector of triode Q8 connects with the base stage of capacitor C20, resistance R48 and triode Q9 respectively；
Capacitor C20 and resistance R48 are grounded respectively；
The emitter of triode Q9 is grounded；
Second part circuit includes output feedback voltage end U0, the output feedback voltage end U0 successively connecting resistance R49 and resistance
R50, the anode of resistance R50 difference the connecting resistance R51 and diode D22；
The anode of resistance R51 difference connecting resistance R52 and diode D23；
Resistance 52 is grounded；
The cathode of diode D22 connects 6 pins of capacitor C22 and comparator U2_B respectively；
Capacitor C22 ground connection；
The cathode of diode D23 connects 2 pins of capacitor C23, the cathode of diode D19 and comparator U2_A respectively；
The anode of diode D19 connects the cathode of capacitor C24, resistance R55, resistance R56 and diode D20 respectively；
Resistance R57 is connected between resistance R55 and resistance R56；
Capacitor C24 and resistance R55 ground connection；
Resistance R56 connects the anode and overcurrent end Imax of diode D21 respectively；
The pin 5 of comparator U2_B meets 3 pins, capacitor C21, resistance R53 and the resistance RC1 of comparator U2_A respectively；
Capacitor C21 and resistance R53 ground connection；
Resistance RC1 connects with resistance RC2, resistance RC2 respectively with resistance R54,8 pins of comparator U2_A, diode D21 yin
Pole and output voltage control end VC connect；
Resistance R54 connects with the anode of 7 pins of comparator U2_B and diode D20 respectively
4 pins of comparator U2_B are grounded；
1 pin of comparator U2_A connects with under-voltage and output over-voltage protection control terminal VP is exported.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811310413.4A CN109347329A (en) | 2018-11-06 | 2018-11-06 | A kind of converter for DC to DC |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811310413.4A CN109347329A (en) | 2018-11-06 | 2018-11-06 | A kind of converter for DC to DC |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109347329A true CN109347329A (en) | 2019-02-15 |
Family
ID=65314218
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811310413.4A Pending CN109347329A (en) | 2018-11-06 | 2018-11-06 | A kind of converter for DC to DC |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110912415A (en) * | 2019-12-11 | 2020-03-24 | 国网山东省电力公司济南供电公司 | Low-power-consumption isolated output household power supply |
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|---|---|---|---|---|
| CN206402100U (en) * | 2016-11-14 | 2017-08-11 | 天津中德应用技术大学 | Two sections of current-limiting protection circuits for small-power DCDC |
| CN206401879U (en) * | 2017-01-22 | 2017-08-11 | 天津中德应用技术大学 | Input undervoltage protection circuit for DC DC |
| CN107465173A (en) * | 2017-08-16 | 2017-12-12 | 中国电子科技集团公司第十八研究所 | A kind of space power system accessory power supply protection circuit |
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|---|---|---|---|---|
| CN206402100U (en) * | 2016-11-14 | 2017-08-11 | 天津中德应用技术大学 | Two sections of current-limiting protection circuits for small-power DCDC |
| CN206401879U (en) * | 2017-01-22 | 2017-08-11 | 天津中德应用技术大学 | Input undervoltage protection circuit for DC DC |
| CN107465173A (en) * | 2017-08-16 | 2017-12-12 | 中国电子科技集团公司第十八研究所 | A kind of space power system accessory power supply protection circuit |
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| CN110912415A (en) * | 2019-12-11 | 2020-03-24 | 国网山东省电力公司济南供电公司 | Low-power-consumption isolated output household power supply |
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