CN107306126A - PWM generation circuit - Google Patents
PWM generation circuit Download PDFInfo
- Publication number
- CN107306126A CN107306126A CN201610263832.1A CN201610263832A CN107306126A CN 107306126 A CN107306126 A CN 107306126A CN 201610263832 A CN201610263832 A CN 201610263832A CN 107306126 A CN107306126 A CN 107306126A
- Authority
- CN
- China
- Prior art keywords
- sawtooth
- circuit
- signal
- generation circuit
- resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000000052 comparative effect Effects 0.000 claims abstract description 5
- 239000000919 ceramic Substances 0.000 claims description 7
- 230000005611 electricity Effects 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 9
- 238000010276 construction Methods 0.000 abstract description 7
- 238000000926 separation method Methods 0.000 abstract description 4
- 238000013461 design Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000007600 charging Methods 0.000 description 1
- 238000010277 constant-current charging Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K7/00—Modulating pulses with a continuously-variable modulating signal
- H03K7/08—Duration or width modulation ; Duty cycle modulation
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention provides the generation circuit of PWM a kind of, wherein, the generation circuit includes：Constant-current source circuit, for providing constant DC current for the electric capacity C1 in sawtooth-wave circuit；The sawtooth-wave circuit, is connected with the constant-current source circuit, the voltage for controlling the electric capacity C1 so that the electric capacity C1 exports sawtooth output signal；Comparison circuit, is connected with the sawtooth-wave circuit, for receiving the sawtooth output signal, the direct current signal inputted according to the sawtooth output signal and controllable direct current power supply, and according to comparative result output pwm signal；Using above-mentioned technical proposal, solve the problems such as increasing system complexity caused by extra single-chip microcomputer of output PWM ripples needs etc. in correlation technique, a kind of controllable PWM wave generation circuits of simple and stable are realized using controllable DC source in the device and existing Industry Control of separation, so that the construction cycle shortens, cost greatly reduces.
Description
Technical field
The present invention relates to the communications field, in particular to the generation circuit of PWM a kind of.
Background technology
In present industrial measurement and control adjustable pulse-width modulation (Pulse Width Modulation,
Referred to as PWM) generator is typically all the single-chip microcomputer output pin that is controlled with mcu programming
Or control special chip to export this mode of PWM ripples to realize.So in test neck
, it is necessary to extra design single chip circuit in domain, and need to realize single-chip microcomputer and upper control
The interface circuit of the communication of machine.So do the just extra design of hardware and software for adding system complicated
Degree, such as single-chip microcomputer needs to do extra software development, makes the cycle stretch-out of exploitation, cost
Increase.
For in correlation technique, output PWM ripples need to increase caused by extra single-chip microcomputer etc.
Adding system complexity, the construction cycle is long, the problem of cost increase, not yet proposes effective solve
Scheme.
The content of the invention
The embodiments of the invention provide the generation circuit of PWM a kind of, at least to solve related skill
Above-mentioned technical problem in art.
According to an aspect of the invention, there is provided a kind of generation of pulse width modulation (PWM)
Circuit, including：Constant-current source circuit, for providing constant for the electric capacity C1 in sawtooth-wave circuit
DC current；The sawtooth-wave circuit, is connected with the constant-current source circuit, for controlling
State electric capacity C1 voltage so that the electric capacity C1 exports sawtooth output signal；Compare electric
Road, is connected with the sawtooth-wave circuit, for receiving the sawtooth output signal, according to institute
The direct current signal of sawtooth output signal and controllable direct current power supply input is stated, and according to comparative result
Output pwm signal.
Alternatively, the constant-current source circuit, including, current source, resistance R1, adjustable resistance
RP1, PNP triode Q1, the current source, resistance R1, adjustable resistance RP1, PNP
Triode Q1 two P poles are connected in series, the N poles of the PNP triode Q1, with institute
State current source and resistance R1 connections.
Alternatively, the adjustable resistance RP1 adjusts the sawtooth by adjusting itself resistance
The cycle of ripple.
Alternatively, the generation circuit, in addition to：Controllable direct current power supply, the controllable direct current
Source is used for the control instruction for receiving controller, and exports voltage corresponding with the control instruction.
Alternatively, the comparison circuit includes：LM2903 chips, divider resistance, for dividing
Press the voltage signal of the controllable current source input.
Alternatively, the direct current that the resistance of the divider resistance is inputted by the controllable direct current power supply
The magnitude of voltage of signal is determined.
Alternatively, the comparison circuit, be additionally operable to sawtooth output signal described in comparison with it is described
Voltage division signal of the direct current signal of controllable direct current power supply input after the divider resistance partial pressure.
Alternatively, the comparison circuit, is additionally operable in the sawtooth output signal more than described
Voltage division signal, the comparison circuit exports low level, when the sawtooth output signal is less than institute
State voltage division signal, export high level, wherein, using the high level and the low level as
Pwm signal.
Alternatively, the sawtooth-wave circuit includes：ICM7555 chips, the electric capacity C1.
Alternatively, the electric capacity C1 includes：COG ceramic condensers, NPO ceramic condensers.
Pass through the present invention, by constant-current source circuit, the interaction of sawtooth-wave circuit and comparison circuit
Process, can easily produce pwm signal excessively, solve output PWM ripples in correlation technique
Need to increase system complexity caused by extra single-chip microcomputer etc., the construction cycle is long, cost increases
Plus the problem of, enter without being additionally required single chip circuit, use the device of separation and existing
Controllable DC source realizes a kind of controllable PWM wave producers of simple and stable in Industry Control
Circuit so that the construction cycle shortens, cost greatly reduces.
Brief description of the drawings
Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the application
A part, schematic description and description of the invention is used to explain the present invention, not structure
Into inappropriate limitation of the present invention.In the accompanying drawings：
Fig. 1 is the structured flowchart of PWM according to embodiments of the present invention generation circuit；
Fig. 2 is the structured flowchart of the generation circuit according to the PWM of optional example of the invention；
Fig. 3 is the knot of the controllable PWM wave generation circuits according to the preferred embodiment of the present invention 1
Structure block diagram.
Embodiment
Describe the present invention in detail below with reference to accompanying drawing and in conjunction with the embodiments.Need explanation
It is that, in the case where not conflicting, the feature in embodiment and embodiment in the application can phase
Mutually combination.
It should be noted that the art in description and claims of this specification and above-mentioned accompanying drawing
Language " first ", " second " etc. are for distinguishing similar object, without specific for describing
Order or precedence.
In embodiments of the present invention there is provided the generation circuit of PWM a kind of, Fig. 1 is basis
The structured flowchart of the PWM of embodiment of the present invention generation circuit, as shown in figure 1, including：
Constant-current source circuit 10, for providing constant direct current for the electric capacity C1 in sawtooth-wave circuit
Electric current；
Sawtooth-wave circuit 12, the voltage for controlling the electric capacity C1 so that the electric capacity
C1 exports sawtooth output signal；
Comparison circuit 14, for receiving the sawtooth output signal, according to the sawtooth waveforms
The direct current signal that output signal and controllable direct current power supply 16 are inputted, and exported according to comparative result
Pwm signal.
By the present invention, carried by constant-current source circuit 10 for the electric capacity C1 in sawtooth-wave circuit
For constant DC current, sawtooth-wave circuit 12 controls electric capacity C1 voltage so that institute
Electric capacity C1 output sawtooth output signals are stated, and then comparison circuit 14 receives the sawtooth waveforms
Output signal, the direct current inputted according to the sawtooth output signal and controllable direct current power supply 16
Signal, and according to comparative result output pwm signal, using above-mentioned technical proposal, solve
PWM ripples are exported in correlation technique to be needed to increase system complex caused by extra single-chip microcomputer etc.
Degree, the construction cycle is long, the problem of cost increase, enters without being additionally required single chip circuit, makes
Realized with controllable DC source in the device and existing Industry Control of separation a kind of simple steady
Fixed controllable PWM wave generation circuits so that the construction cycle shortens, and cost greatly reduces.
Fig. 2 is the structured flowchart of the generation circuit according to the PWM of optional example of the invention, such as
Shown in Fig. 2, constant-current source circuit 10, including, current source, resistance R1, adjustable resistance RP1,
PNP triode Q1, the current source, resistance R1, adjustable resistance RP1, PNP triode
Q1 two P poles are connected in series, the N poles of the PNP triode Q1, with the electric current
Source and resistance R1 connections；Sawtooth-wave circuit 12 includes：ICM7555 chips, electric capacity C1；
Comparison circuit 14 includes：LM2903 chips, divider resistance, for controllable electric described in partial pressure
The voltage signal of stream source input；Above-mentioned generation circuit, in addition to：(the figure of controllable direct current power supply 16
Program control direct voltage source 16 is presented as in 2), the controllable direct current power supply is used to receive controller
Control instruction, and export voltage corresponding with the control instruction.
Situation, in embodiments of the present invention, adjustable resistance are illustrated based on the circuit shown in Fig. 2
RP1 adjusts the cycle of the sawtooth waveforms by adjusting itself resistance；The resistance of divider resistance is led to
The magnitude of voltage for crossing the direct current signal of the controllable direct current power supply input is determined.
Alternatively, the comparison circuit, be additionally operable to sawtooth output signal described in comparison with it is described
Voltage division signal of the direct current signal of controllable direct current power supply input after the divider resistance partial pressure,
Based on this, it is more than the voltage division signal in the sawtooth output signal, the comparison circuit is defeated
Go out low level, when the sawtooth output signal is less than the voltage division signal, export high level,
Wherein, the high level and the low level are regard as pwm signal.
In order that it is stable, electric capacity C1 prioritizing selections COG potteries to obtain the voltage on electric capacity C1
Porcelain electric capacity, NPO ceramic condensers.
Above-mentioned PWM generation circuit is explained below in conjunction with two preferred embodiments,
But it is not used in the restriction embodiment of the present invention.
Preferred embodiment 1
The preferred embodiment of the present invention 1 provides a kind of linear remote-controllable of simple high stable
PWM wave generation circuits, Fig. 3 is the controllable PWM according to the preferred embodiment of the present invention 1
The structured flowchart of wave generation circuit, the circuit can be embodied by following module：TL431 structures
Into constant-current source circuit module 30 (equivalent to for the constant-current source circuit 10 in Fig. 1), sawtooth waveforms
Circuit module 32 (equivalent to the sawtooth-wave circuit module 12 in Fig. 1), circuit and square-wave module
34 (equivalent to the comparison circuits 14 in Fig. 1) and program control direct current source module 36 (equivalent to
Controllable direct current power supply 16 in Fig. 1).
Such as Fig. 2, shown in 3, the constant-current source circuit that TL431 is constituted be to provide a constant-current source to
Electric capacity C1, provides a constant current source for electric capacity C1, so can guarantee that filling on C1
Piezoelectric voltage waveform is exactly a linear waveform.And C1 and ICM7555 constitute sawtooth waveforms electricity
Road.Because when C1 voltage linear has risen to 2/3VCC (supply voltage),
Discharge loop will be opened inside ICM7555, C1 voltage can be pulled down to 1/3VCC moment by it
Level.Then ICM7555 inside discharge circuit cut-off, such constant-current source continue again to
C1 charges.Go round and begin again, (the 2 of ICM7555,6, the 7 pins) shape on electric capacity C1
Into the signal of a cycle sawtooth waveforms.In order that electric capacity C1 capacitance is not by temperature, the time
Influence, electric capacity C1 preferably uses the ceramic condenser of COG/NPO types.Circuit and square-wave is exactly
The comparison circuit that one amplifier LM2903 is constituted.The voltage inputted when the anode of amplifier
(control voltage sent from program control DC source passes through resistance R3, R4 voltage division signal) is more than
During amplifier negative terminal input voltage (i.e. the cycle sawtooth signal of sawtooth-wave circuit output), amplifier is defeated
It is high level to go out end.When the voltage that the anode of amplifier is inputted is less than amplifier negative terminal input voltage,
Amplifier output end is low level.Program control DC source output voltage is in amplifier anode input voltage
Within electric capacity C1 voltage change range (1/3VCC~2/3VCC), so in output end just
The square-wave signal of a cycle fixation is formd, its cycle is equal to the sawtooth waveforms letter on electric capacity C1
Number cycle.When program control DC source changes voltage under host computer procedure control, this square wave
The dutycycle of signal also can be with change, and material is thus formed pwm signal.And this PWM
Signal can easily go to control some heating sources, adjustable speed fan etc., realize the one of control system
Body, the preferred embodiment of the present invention 1 is not construed as limiting to this.
The above-mentioned technical proposal provided using the preferred embodiment of the present invention 1, without single chip circuit
And Software for Design, the progress of simplify control process, reach same stably and controllable PWM effects
Really, cost is saved, the efficiency that whole control system is built is improved.
Preferred embodiment 2
As shown in Fig. 2 constant-current source circuit includes U3-TL431, resistance R1, adjustable resistance
RP1 and PNP triode Q1, TL431 are 2.5V a reference source devices, and resistance R1 is carried
The bias current of TL431 steady operations is supplied.PNP triode Q1 is made using a reversal connection
With mode, the pressure difference of its C pole and B poles is stable, so has one at RP1 2 ends
Stable pressure difference.So Q1 E poles output a constant electric current after being powered up.And
By adjusting RP1 size, this current value can be adjusted, so as to change the oblique of C1 chargings
Rate, and then the cycle (frequency in other words) of the whole sawtooth waveforms of regulation and PWM ripples.
Sawtooth-wave circuit in Fig. 3 is (in order to true by ICM7555 and charge and discharge capacitance C1
The capacity stability of C1 electric capacity is protected, it preferably uses COG/NPO ceramic condensers), filtered electrical
Hold C2 compositions.2 comparators, 6 pin Threshold and 2 pin trigger are had in ICM7555
The anode input of a comparator and the negative terminal input of another comparator are connected to respectively.6
It is 2/3VCC that the other end voltage of the comparator of pin connection, which is fixed, and the comparison of 2 pin connection
The other end fixed voltage of device is 1/3VCC.On circuit after electricity, ICM7555 7 pin
The internal discharge loop of Discharge pin connection is OFF state, with above said constant-current source
Circuit starts to give electric capacity C1 constant-current charges, when voltage has exceeded 2/3VCC, 7 pin
The internal discharge loop state of Discharge pin connection is inverted to ON states, then internal to put
Electrical circuit is pulled down to ground, the electric charge that C1 is stored is discharged rapidly, until the voltage on C1 is low
When 1/3VCC, the internal discharge loop state of 7 pin Discharge pin connection switches to OFF
State, such electric capacity C1 voltage is again in the rise of constant current charging mode lower linear.Go round and begin again,
Cycle sawtooth output signal is formd on electric capacity C1.
Circuit and square-wave module is made up of comparator LM2903, and its input signal has 2.One
It is the cycle sawtooth signal on above-mentioned C1, is connected on the negative terminal of comparator.Other one
The individual program-controlled voltage for being exactly program control DC source output is by straight after resistance R3 and R4 partial pressure
Signal is flowed, this is connected on comparator LM2903 anode.When the voltage division signal of program control DC source
During more than sawtooth voltage on C1, comparator exports a high level；When program control DC source
Voltage division signal less than sawtooth voltage on C1 when, comparator exports a low level.This
Sample is formed the square-wave signal of a fixed duty cycle.But because host computer can pass through
The output voltage of GPIB/RS232 mouthfuls of remote control this program control DC source, then can just make
This square-wave signal under program, becomes required pwm signal.And due to perseverance
The effect of current charge, makes this regulation to accomplish linear regulation, facilitates the program of host computer
Design.
In summary, the embodiment of the present invention has reached following technique effect：Solve correlation technique
Middle output PWM ripples need to increase system complexity caused by extra single-chip microcomputer etc., develop
Cycle is long, the problem of cost increase, enters without being additionally required single chip circuit, uses separation
Controllable DC source realizes a kind of the controllable of simple and stable in device and existing Industry Control
PWM wave generation circuits so that the construction cycle shortens, and cost greatly reduces.
The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention,
For those skilled in the art, the present invention can have various modifications and variations.It is all this
Within the spirit and principle of invention, any modification, equivalent substitution and improvements made etc. all should
Within protection scope of the present invention.
Claims (10)
1. a kind of generation circuit of pulse width modulation (PWM), it is characterised in that bag
Include：
Constant-current source circuit, for providing constant straight for the electric capacity C1 in sawtooth-wave circuit
Flow electric current；
The sawtooth-wave circuit, is connected with the constant-current source circuit, for controlling the electricity
Hold C1 voltage so that the electric capacity C1 exports sawtooth output signal；
Comparison circuit, is connected with the sawtooth-wave circuit, defeated for receiving the sawtooth waveforms
Go out signal, believed according to the direct current that the sawtooth output signal and controllable direct current power supply are inputted
Number, and according to comparative result output pwm signal.
2. generation circuit according to claim 1, it is characterised in that
The constant-current source circuit, including, current source, resistance R1, adjustable resistance RP1,
PNP triode Q1, the current source, resistance R1, adjustable resistance RP1, PNP tri-
Pole pipe Q1 two P poles are connected in series, the N poles of the PNP triode Q1, with
Current source and resistance the R1 connections.
3. generation circuit according to claim 2, it is characterised in that it is described can
Resistance RP1 is adjusted to adjust the cycle of the sawtooth waveforms by adjusting itself resistance.
4. generation circuit according to claim 1, it is characterised in that
The generation circuit, in addition to：Controllable direct current power supply, the controllable direct current power supply is used
In the control instruction for receiving controller, and export voltage corresponding with the control instruction.
5. generation circuit according to claim 1, it is characterised in that
The comparison circuit includes：LM2903 chips, divider resistance, for partial pressure institute
State the voltage signal of controllable current source input.
6. generation circuit according to claim 5, it is characterised in that described point
The magnitude of voltage for the direct current signal that the resistance of piezoresistance is inputted by the controllable direct current power supply
It is determined that.
7. generation circuit according to claim 5, it is characterised in that
The comparison circuit, be additionally operable to sawtooth output signal described in comparison with it is described controllable
Voltage division signal of the direct current signal of DC supply input after the divider resistance partial pressure.
8. generation circuit according to claim 7, it is characterised in that
The comparison circuit, is additionally operable to be more than the partial pressure in the sawtooth output signal
Signal, the comparison circuit exports low level, when the sawtooth output signal is less than institute
Voltage division signal is stated, high level is exported, wherein, the high level and the low level are made
For pwm signal.
9. generation circuit according to claim 1, it is characterised in that
The sawtooth-wave circuit includes：ICM7555 chips, the electric capacity C1.
10. the generation circuit according to claim any one of 1-9, it is characterised in that
The electric capacity C1 includes：COG ceramic condensers, NPO ceramic condensers.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610263832.1A CN107306126A (en) | 2016-04-25 | 2016-04-25 | PWM generation circuit |
| PCT/CN2017/081912 WO2017186104A1 (en) | 2016-04-25 | 2017-04-25 | Pwm generation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610263832.1A CN107306126A (en) | 2016-04-25 | 2016-04-25 | PWM generation circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107306126A true CN107306126A (en) | 2017-10-31 |
Family
ID=60150584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610263832.1A Withdrawn CN107306126A (en) | 2016-04-25 | 2016-04-25 | PWM generation circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN107306126A (en) |
| WO (1) | WO2017186104A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111490760A (en) * | 2020-05-19 | 2020-08-04 | 广东海悟科技有限公司 | High-precision analog quantity output method, device and equipment of single chip microcomputer based on PWM waveform |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104122924A (en) * | 2014-07-18 | 2014-10-29 | 苏州华兴源创电子科技有限公司 | Switch-type voltage stabilizing circuit and constant voltage constant current generation circuit with switch-type voltage stabilizing circuit |
| CN204090126U (en) * | 2014-08-18 | 2015-01-07 | Tcl通力电子（惠州）有限公司 | Audio frequency PWM circuit and stereo set |
| US8994309B2 (en) * | 2012-11-01 | 2015-03-31 | Samsung Electro-Mechanics Co., Ltd. | Pulse width modulation signal generating circuit and motor driving circuit |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007120001A1 (en) * | 2006-04-18 | 2007-10-25 | Lg Innotek Co., Ltd | Pulse width modulation apparatus and apparatus for driving light source having the same |
| CN101621288B (en) * | 2009-07-29 | 2011-08-31 | 南京航空航天大学 | Circuit for converting PWM output mode into PFM output mode |
| CN101984558A (en) * | 2010-09-25 | 2011-03-09 | 苏州华芯微电子股份有限公司 | High-performance saw-tooth wave generating circuit controlled by digital circuit and method thereof |
| CN102307044B (en) * | 2011-09-14 | 2013-11-13 | 深圳航天科技创新研究院 | Switching power supply PWM (pulse width modulation) controller with variable frequencies |
-
2016
- 2016-04-25 CN CN201610263832.1A patent/CN107306126A/en not_active Withdrawn
-
2017
- 2017-04-25 WO PCT/CN2017/081912 patent/WO2017186104A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8994309B2 (en) * | 2012-11-01 | 2015-03-31 | Samsung Electro-Mechanics Co., Ltd. | Pulse width modulation signal generating circuit and motor driving circuit |
| CN104122924A (en) * | 2014-07-18 | 2014-10-29 | 苏州华兴源创电子科技有限公司 | Switch-type voltage stabilizing circuit and constant voltage constant current generation circuit with switch-type voltage stabilizing circuit |
| CN204090126U (en) * | 2014-08-18 | 2015-01-07 | Tcl通力电子（惠州）有限公司 | Audio frequency PWM circuit and stereo set |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111490760A (en) * | 2020-05-19 | 2020-08-04 | 广东海悟科技有限公司 | High-precision analog quantity output method, device and equipment of single chip microcomputer based on PWM waveform |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017186104A1 (en) | 2017-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102882377B (en) | Synchronous rectifying control method and circuit | |
| CN107995736B (en) | LED drive circuit, power converter and control method | |
| CN104125692A (en) | Multiway LED constant current controller and control method | |
| CN104521326A (en) | Light emitting diode driving apparatus and semiconductor device | |
| CN106487225A (en) | Switching power unit | |
| CN101340150A (en) | Switching power supply apparatus | |
| CN103501112A (en) | Synchronous rectification control method, synchronous rectification control circuit and switch-type voltage regulator | |
| CN104917377B (en) | DC/DC converter | |
| CN105846681B (en) | Switching power unit | |
| CN104202874B (en) | The LED drive circuit of a kind of single inductance and driving method | |
| CN105592590B (en) | A kind of invariable power LED drive power circuit system | |
| CN107071985A (en) | One kind control circuit and light fixture | |
| CN102761274A (en) | System and method for controlling threshold jitter frequency of original-side feedback AC-DC switching power supply | |
| CN103701421B (en) | Volume regulating device, volume regulating method and electronic equipment | |
| TW201143265A (en) | A heterodyne dual slope frequency generation method for the load change of power supply | |
| CN101447638B (en) | Laser excitation power supply and excitation method thereof | |
| CN104578774A (en) | Step-down converter based on output voltage ripple control | |
| CN107306126A (en) | PWM generation circuit | |
| CN117353431A (en) | Circuit structure with adjustable duty ratio | |
| CN103580508B (en) | Ac/dc converter circuit | |
| CN105449995B (en) | Drive control circuit and drive control method and Switching Power Supply | |
| CN205647333U (en) | Motor speed regulating device and domestic appliance | |
| CN104682687B (en) | Soft start-based voltage regulating circuit and soft start method thereof | |
| CN107104594A (en) | Switching regulaor | |
| CN106061037A (en) | LED driving circuit with power factor correction and driver |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20171031 |