CN204559947U - City network alarm is with starting LED drive circuit fast - Google Patents
City network alarm is with starting LED drive circuit fast Download PDFInfo
- Publication number
- CN204559947U CN204559947U CN201520178378.0U CN201520178378U CN204559947U CN 204559947 U CN204559947 U CN 204559947U CN 201520178378 U CN201520178378 U CN 201520178378U CN 204559947 U CN204559947 U CN 204559947U
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- China
- Prior art keywords
- drive circuit
- led drive
- output
- input
- network alarm
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Abstract
City network alarm is with starting LED drive circuit fast, comprise feedback control loop and power tube, it is characterized in that, also comprise the start detection resistance joined with load LED strip, and to the start detection amplifier that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described start detection amplifier and power on detection circuit is connected with the input of trigger and reset terminal respectively; The output of described alternative gating switch is connected with the input of PWM comparator.Adopt city described in the utility model network alarm with starting LED drive circuit fast, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Description
Technical field
The utility model belongs to integrated circuit (IC) design field, relates to Switching Power Supply, and particularly a kind of city network alarm is with starting LED drive circuit fast.
Background technology
The one of semiconductor diode, can become luminous energy electric energy conversion.Light-emitting diode is the same with general-purpose diode to be made up of a PN junction, also has unilateral conduction.After adding forward voltage to light-emitting diode, be injected into the hole in N district from P district and be injected into the electronics in P district by N district.
LED can only toward a direction conducting (energising), be called forward bias (forward bias), when the current flows, electronics and hole compound and send monochromatic light within it, this is electroluminescent effect, compare with neon lamp with incandescent lamp bulb, the feature of light-emitting diode is: operating voltage very low (more several volts had); Operating current very little (the only zero point several milliamperes had can be luminous); Shock resistance and anti-seismic performance good, reliability is high, and the life-span is long; Can the power of modulated luminescence easily by modulating that the electric current that passes through is strong and weak.Owing to there being these features, utilizing and emitting ledly carry out illumination and be applied in more and more widely among scope.
In existing single-stage high-power rate factor LED illumination drive scheme, bulky capacitor in parallel (usual hundreds of microfarad) is needed to reduce the ripple of LED at LED output.This electric capacity initial voltage is 0V, needs the operating voltage tens volts of stable states charging to LED.If the soft start not adding chip internal controls, then easily there is output voltage overshoot when startup and cause LED to have startup Transient Currents.And chip internal increases soft start control, then can increase start-up time entirely bright from switch opens to LED, be difficult to needs start-up time meeting <0.5S.
Utility model content
For improving the toggle speed of LED drive circuit, the utility model discloses a kind of city network alarm with starting LED drive circuit fast.
City described in the utility model network alarm is with starting LED drive circuit fast, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output voltage of LED drive circuit;
Also comprise the start detection resistance joined with load LED strip, and to the start detection amplifier that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described start detection amplifier and power on detection circuit is connected with the input of trigger and reset terminal respectively;
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output of described alternative gating switch is connected with the input of PWM comparator;
The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier.
Preferably, described high position reference voltage is the described city network alarm supply voltage starting LED drive circuit fast.
Preferably, also comprise sample circuit, described sample circuit is the divider resistance string be connected between output voltage terminal and ground, and the divider node of divider resistance string is connected to the input of error amplifier.
Preferably, also building-out capacitor is connected with between described error amplifier and ground.
Preferably, described trigger is rest-set flip-flop.
Preferably, described power on detection circuit is the start-up capacitance being connected to flipflop input terminal, and described start-up capacitance is connected between power input and ground.
Adopt city described in the utility model network alarm with starting LED drive circuit fast, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Accompanying drawing explanation
Fig. 1 illustrates a kind of embodiment structural representation of the present utility model.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described in further detail.
City described in the utility model network alarm is with starting LED drive circuit fast, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output voltage of LED drive circuit.
Also comprise the start detection resistance joined with load LED strip, and to the start detection amplifier that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described start detection amplifier and power on detection circuit is connected with the input of trigger and reset terminal respectively.
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output of described alternative gating switch is connected with the input of PWM comparator; The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier.
Embodiment as shown in Figure 1, power on detection circuit is the start-up capacitance being connected to flipflop input terminal, described start-up capacitance is connected between power input and ground, start-up capacitance charging when powering on, voltage rises gradually, and in uphill process, trigger exports high level signal, and trigger can select the simplest rest-set flip-flop formed with door by two, flipflop output signal, to single-pole double-throw switch (SPDT), controls single-pole double-throw switch (SPDT) and is connected between PWM input and high position reference voltage.
Startup stage, as shown in Figure 1, two inputs of PWM comparator are connected between high position reference voltage and triangular-wave generator, high position reference voltage is higher than the supply voltage of error amplifier, PWM is made to compare the output voltage maximum being necessarily greater than error amplifier by comparative voltage of input, PWM comparator runs with maximum duty cycle, and the maximum duty cycle exporting square wave is determined by triangular-wave generator.After logic drive circuit, the square wave driving power pipe MN1 of this maximum duty cycle runs with maximum duty cycle, and output voltage rises fast, and in FIG, high position reference voltage directly can select the supply voltage VIN inputted, and need not redesign internal module.
Startup stage, because output voltage is not enough, the load LED of cascade cannot conducting, start detection resistance RCS does not have electric current to flow through, two ends pressure reduction is zero, when output voltage VO UT rises to certain value, such as each load LED conducting needs 3V voltage, then 10 LED strip connection need 30V to get final product conducting, now load LED conducting, generation current on RCS, RCS two ends produce pressure drop, start detection amplifier output level reverses, flipflop output signal is reset, control alternative gating switch error amplifier output is connected with PWM comparator input terminal, thus realize normal FEEDBACK CONTROL, startup stage big space rate promote output voltage VO UT process and terminate.
Also sample circuit is comprised in embodiment shown in Fig. 1, described sample circuit is the divider resistance string be connected between output voltage terminal and ground, the divider node of divider resistance string is connected to the input of error amplifier, such as be made up of R1 and R2 two divider resistances, sample circuit output is divider node.Sampling end voltage in proportion can be reduced to error amplifier by which can in detection range.
Preferably, between the output of described error amplifier and ground, be connected with building-out capacitor C2, a dominant pole can be provided for control loop, the stability that reinforcing feedback controls.Switching Power Supply topology in Fig. 1 can be the various Switching Power Supply structures comprising power tube, such as BUCK, BUCK-BOOST etc.
Adopt city described in the utility model network alarm with starting LED drive circuit fast, by detecting the on off state of output voltage control power tube, startup stage with big space rate continuous service until meet the turn-on condition of load LED, improve the rate of climb of output voltage, shorten start-up time.
Previously described is each preferred embodiment of the present utility model, preferred implementation in each preferred embodiment is if not obviously contradictory or premised on a certain preferred implementation, each preferred implementation can stack combinations use arbitrarily, design parameter in described embodiment and embodiment is only the utility model proof procedure in order to clear statement utility model people, and be not used to limit scope of patent protection of the present utility model, scope of patent protection of the present utility model is still as the criterion with its claims, the equivalent structure change that every utilization specification of the present utility model and accompanying drawing content are done, in like manner all should be included in protection range of the present utility model.
Claims (6)
1. city network alarm is with starting LED drive circuit fast, comprise feedback control loop and power tube, described feedback control loop comprises error amplifier, PWM comparator, logic drive circuit, the output of described logic drive circuit is connected with the control end of power tube, and described error amplifier is for detecting the output voltage of LED drive circuit;
It is characterized in that, also comprise the start detection resistance joined with load LED strip, and to the start detection amplifier that the ohmically pressure drop of start detection detects, and for the power on detection circuit that testing circuit powers on, the output of described start detection amplifier and power on detection circuit is connected with the input of trigger and reset terminal respectively;
The output of described error amplifier connects the first input end connection of alternative gating switch, and the second input of described alternative gating switch is connected with high position reference voltage; The described control end of alternative gating switch is connected with the output of trigger, and the output of described alternative gating switch is connected with the input of PWM comparator;
The reference voltage value of described high position reference voltage is not less than the supply voltage of error amplifier.
2. city network alarm, with starting LED drive circuit fast, is characterized in that as claimed in claim 1, and described high position reference voltage is the described city network alarm supply voltage starting LED drive circuit fast.
3. as claimed in claim 1 city network alarm with starting LED drive circuit fast, it is characterized in that, also comprise sample circuit, described sample circuit is the divider resistance string be connected between output voltage terminal and ground, and the divider node of divider resistance string is connected to the input of error amplifier.
4. city as claimed in claim 1 network alarm is with starting LED drive circuit fast, it is characterized in that, is also connected with building-out capacitor between described error amplifier and ground.
5. city network alarm, with starting LED drive circuit fast, is characterized in that as claimed in claim 1, and described trigger is rest-set flip-flop.
6. city network alarm, with starting LED drive circuit fast, is characterized in that as claimed in claim 1, and described power on detection circuit is the start-up capacitance being connected to flipflop input terminal, and described start-up capacitance is connected between power input and ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520178378.0U CN204559947U (en) | 2015-03-27 | 2015-03-27 | City network alarm is with starting LED drive circuit fast |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520178378.0U CN204559947U (en) | 2015-03-27 | 2015-03-27 | City network alarm is with starting LED drive circuit fast |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204559947U true CN204559947U (en) | 2015-08-12 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520178378.0U Expired - Fee Related CN204559947U (en) | 2015-03-27 | 2015-03-27 | City network alarm is with starting LED drive circuit fast |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204559947U (en) |
-
2015
- 2015-03-27 CN CN201520178378.0U patent/CN204559947U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150812 Termination date: 20170327 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |