CN204335105U - The noninductive high frequency switch power of transless that a kind of LED illumination drives - Google Patents

Abstract

The utility model discloses the noninductive high frequency switch power of transless that a kind of LED illumination drives; comprise seven circuit; Part I is current rectifying and wave filtering circuit; Part II is adjustment executive circuit; Part III is reference voltage circuit, and Part IV is sample circuit, and Part V is error amplifying circuit; Part VI is that upper and lower limit detects and ON-OFF control circuit, and Part VII is overcurrent, overvoltage, overheating protection circuit.The utility model energy-conserving and environment-protective, small volume, facilitate integrated, can meet and apply widely, eliminate the devices such as bulky transformer, inductance, the especially employing of duplicate supply, operating circuit uses 3 ~ 5V voltage, the LED drive power of different output voltage only need adjust a small amount of resistance (external or loong shunt), makes internal pull-up circuit curable, thus can realize integrated (IC) change more easily, suitable for mass production, Electro Magnetic Compatibility is good.

Description

The noninductive high frequency switch power of transless that a kind of LED illumination drives

Technical field

The utility model relates to the noninductive high frequency switch power of transless that a kind of LED illumination drives.

Background technology

1. LED is different from traditional illuminating lamp, and its application process has embedded, lamp.Various Embedded application is mainly different with the difference of electronics, power equipment, designs greatly variable.Lamp from initial independent Novel LED light till now with the LED of conventional electric power illuminating lamp compatibility, screw lamp bubble, socket bulb formula, cast lamp-based, template lamp-based etc. can be had.Although the exploitation of LED light be brand-new, restriction is few, because the restriction promotion conference by existing social resources system is difficult; Obviously the restriction do not promoted with the LED of traditional lighting lamp compatibility, on the contrary because the advantages such as safety, low consumption, longevity, low temperature, insulation, use are flexible are more easily promoted, therefore should put forth effort to develop the LED with tradition compatibility.

Compatible requirement brings larger challenge to the design of LED driving power.The position uniquely can hidden oneself because of its driving power only has the two ends of the screw socket of various light fixture, socket or tube lamp, the size of these positions is only had an appointment the diameter (about 100 ~ 1200mm2 cross section) of 10 ~ 40mm, space that 30 ~ 50mm is high usually, in small size like this, to hide oneself driving power, must adopt modularization integrated device to solve, design is containing isolating transformer, without inductance, contain electrochemical capacitor and high efficiency circuit less.

2. traditional high-frequency switch DC power makes Correctional tube be operated in HF switch state, regulation output voltage is carried out by the duty cycle of switching changing Correctional tube, not only significantly can reduce the power consumption of Correctional tube, also because high frequency makes transformer volume of transformer greatly reduce, thus significantly reduce circuit volume, make efficiency significantly bring up to about 90%; But owing to still needing high-frequency isolation transformer, inductance component, electrochemical capacitor etc., for LED lamp, circuit volume is still aobvious large, and the energy consumption of control circuit even arrives a watt level in hundreds of milliwatt, compare with the LED illumination lamp of own power only watt level or hundreds of milliwatt, the energy consumption of control circuit is obviously excessive, so traditional high-frequency switch DC power is not obviously the driving power that optimum is used as LED.

3. conventional highfrequency Switching Power Supply, owing to being operated on off state, add the energy conversion of transformer, inductance etc., its electromagnetic interference is higher, and the difficulty that EMC solves is larger.

Summary of the invention

Technical problem to be solved in the utility model is to provide one directly can connect AC power circuit, transless, without inductance part, few electromagnetic compatibility disturbs, volume is little, the LED driver that efficiency is high, the noninductive high frequency switch power of transless that the LED illumination with voltage stabilizing function drives.

The utility model is achieved through the following technical solutions: the noninductive high frequency switch power of transless that a kind of LED illumination drives; it is characterized in that: comprise seven circuit; Part I is current rectifying and wave filtering circuit; Part II is adjustment executive circuit; Part III is reference voltage circuit; Part IV is sample circuit; Part V is error amplifying circuit; Part VI is that upper and lower limit detects and ON-OFF control circuit; Part VII is overcurrent, overvoltage, overheating protection circuit, and described current rectifying and wave filtering circuit is piled by V1 ~ V4 bridge and filter capacitor C1 forms.

As preferred technical scheme, described adjustment executive circuit is installed between current rectifying and wave filtering circuit and ON-OFF control circuit.

As preferred technical scheme, one end and the current rectifying and wave filtering circuit of described ON-OFF control circuit electrically connect.

As preferred technical scheme, the output of described reference voltage circuit and the input of sample circuit electrically connect.

As preferred technical scheme, the two ends of described current rectifying and wave filtering circuit are provided with load, and described adjustment executive circuit is installed on load one end.

As preferred technical scheme, the output of described error amplifying circuit detects with upper and lower limit and the input of ON-OFF control circuit is connected.

As preferred technical scheme, the output of described sample circuit is connected with the input of error amplifying circuit.

As preferred technical scheme, the working power of described reference voltage circuit is 3-5V.

The beneficial effects of the utility model are:

1. simplified control circuit and reduction control electric current

Typical high frequency switch power has oscillating circuit, reference power supply and circuit, duty cycle adjustment control circuit and overvoltage protection, overtemperature protection, current foldback circuit, and circuit is more complicated.The design will based on features such as LED low consumption, electric current and voltage are non-linear, and on the basis of common high frequency switch power, the mode that design utilizes high frequency ripple resonance to control high frequency adjustment switch builds high frequency switch power; Basic scheme is: when energized, high frequency adjustment switch " is opened ", output voltage rises, prescribe a time limit when output voltage rises to the upper of setting, control adjustment switch " passs ", output voltage by electric capacity to load discharge, when voltage drop to set lower prescribe a time limit, again control adjustment switch " to open ", move in circles like this, Correctional tube realizes resonant mode " switch " work, thus simplified control circuit, reduction control electric current, reduce the wastage.

2. adopt the drive power mode of non-isolated LED

LED oneself power consumption is low, it is little to generate heat, easy employing plastic material carries out product encapsulation, can easily reach good insulation, therefore the design adopts the mode saving high-frequency isolation transformer, and the least possible electric capacity (if desired adopt small size electrochemical capacitor), do not adopt inductance, operating circuit will directly be connected with load (usually in parallel with load), thus volume can be reduced, realize integrated.For few employing electric capacity, also make circuit design should adopt high-frequency and high voltage, small area analysis (to improve load equivalent impedance) as far as possible.

3. reduce volume, obtain more many application

Owing to there is no transformer and inductance component, volume can be accomplished very little, add the components and parts of main body, be all resistance, diode, triode etc., facilitate circuit integration (burning till IC), as required electric capacity, can make stacked plate, then be rolled into hollow cylinder, place IC integration slice in the middle of hollow cylinder, the installation question of electric capacity and chip can be solved like this.Or also it is contemplated that face of being made by electric capacity is cylindrical, get connecting pin in both ends of the surface, as button cell shape, form the layout of C1, IC sheet, C2 serial connection.Also paster multi-layer ceramic capacitance can directly be adopted, specifically depending on power output.

4. series connection is main LED cascade mode (realizing primarily of LED lamp designer)

Because LED operating voltage is lying prostrate level, operating current at about ten milliamperes, therefore will obtain high-power LED lamp needs some LEDs serial or parallel connections.For reducing circuit loss, LED should adopt series system to be that main acquisition is high-power, only when serial number makes operating voltage reach alternating supply voltage lower limit too much and is not easy to control circui, then considers to adopt in parallel, namely first after string and instead of first and after go here and there.Such as: under alternating current 220V voltage (after rectifying and wave-filtering about more than 300V direct current), the LED of single operating voltage 2.7V, rated current 12mA connects at most no more than about 100 (gross power is about 3.2W); Namely above-mentioned LED only adopts the maximum LED realized more than about 3 watts of series connection, and power will significantly increase again just needs parallel connection again on the basis of series connection.Specifically how to go here and there also, should according to LED design power (illumination), easily manufactured, be convenient to design on control circuit, be convenient to application etc. consider.

Accompanying drawing explanation

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiments more of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is principle assumption diagram of the present utility model;

Fig. 2 is the circuit diagram of current rectifying and wave filtering circuit;

Fig. 3 is circuit diagram of the present utility model;

Fig. 4 is another circuit diagram of the present utility model.

Embodiment

All features disclosed in this specification, or the step in disclosed all methods or process, except mutually exclusive feature and/or step, all can combine by any way.

Arbitrary feature disclosed in this specification (comprising any accessory claim, summary and accompanying drawing), unless specifically stated otherwise, all can be replaced by other equivalences or the alternative features with similar object.That is, unless specifically stated otherwise, each feature is an example in a series of equivalence or similar characteristics.

As shown in Figure 1, Figure 2, Figure 3 and Figure 4; the noninductive high frequency switch power of transless that a kind of LED illumination of the present utility model drives; it is characterized in that: comprise seven circuit; Part I is current rectifying and wave filtering circuit; Part II is adjustment executive circuit; Part III is reference voltage circuit; Part IV is sample circuit; Part V is error amplifying circuit; Part VI is that upper and lower limit detects and ON-OFF control circuit; Part VII is overcurrent, overvoltage, overheating protection circuit, and described current rectifying and wave filtering circuit is piled by V1 ~ V4 bridge and filter capacitor C1 forms.

Adjustment executive circuit is installed between current rectifying and wave filtering circuit and ON-OFF control circuit.One end and the current rectifying and wave filtering circuit of ON-OFF control circuit electrically connect.The output of reference voltage circuit and the input of sample circuit electrically connect.The two ends of current rectifying and wave filtering circuit are provided with load, and described adjustment executive circuit is installed on load one end.The output of error amplifying circuit detects with upper and lower limit and the input of ON-OFF control circuit is connected.The output of sample circuit is connected with the input of error amplifying circuit.The working power of reference voltage circuit is 3-5V.

Part I current rectifying and wave filtering circuit, is shown in accompanying drawing two, and this part is piled by V1 ~ V4 bridge and filter capacitor C1 forms.The capacity of electric capacity is estimated according to=RC=(3-5) T, if U0=72V, then R=72V/12mA=6k Ω, C=(3 ~ 5) T/R=(3 ~ 5)/(50*6) * 10-3=10 ~ 16uF, under same power, the operating voltage of LED is lower, electric current is larger, and capacitance requirements is larger.Forward conduction voltage, on the contrary withstand voltage, maximum operating currenbt are mainly considered in the selection of rectifier diode (bridge heap), forward conduction voltage be generally 0.7 volt, on the contrary requirement of withstand voltage be greater than 400 ~ 450V, maximum operating currenbt should consider electric capacity impulse current, desirable 15 ~ 20 times of operating currents (250mA), and these parameters should be easy to meet; Or adopt Schottky diode forward voltage drop can decline to a great extent 0.2 ~ 0.3 volt, thus the pipe consumption of rectifying tube can be reduced.

Part II is adjustment execution (HF switch) circuit, and V5 performs pipe for adjusting, and it on off state, needs the pipe selecting applicable high voltage (400V ~ 450V), high-frequency (hundred more than kHz) works with high-frequency operation.Basic functional principle: pile rectification through V1 ~ V4 bridge be filtered into more than 300V direct current through C1 again when 220V after energising exchanges, during owing to being just energized, output voltage is zero, I4 leg open, electric current is zero (namely control circuit is not operating); By the loading of 300V voltage, this voltage is loaded into the grid of V5 igbt through R1 and makes Correctional tube saturation conduction and "ON", the supply load while that C1 charging rapidly to C2, and output voltage rises at once; Upper prescribing a time limit is allowed when output voltage rises to, control circuit is by cut out Correctional tube, namely carry out "Off" control---and-I4 branch road is shorted to negative, flowing through resistance R1 electric current I 1 all enters negative, under output voltage effect, reverse-biased and end through R2, R3 dividing potential drop by output voltage between the grid source of V5 insulated gate bipolar field effect transistor, Correctional tube turns off, C2 slowly declines by electric discharge index to load discharge, output voltage, when output voltage drops to permission lower limit (minimum), control circuit controls again Correctional tube "ON", is formed toward complex resonance.

Circuit work frequency depends on that C1 is to the charging interval of C2 and C2 sum discharge time (it is reciprocal is resonance frequency) to load; Because C1 is extremely short to the charging interval of C2, frequency will depend primarily on load impedance and output loop meets electric capacity C2, discharge time constant=RL*C2, T=1/f=(0.01-0.001); If f gets 100KHz, then=(1-10) 10-3s.Be 13mA, RL=80/13=6K, C2=(1 ~ 10) 10-3/6K=0.17 ~ 1.7uF when U0 is 80V, I0, should more than 1uF be got; Be 4mA, RL=4/4=1K, C2=(1 ~ 10) 10-3/1K=1 ~ 10uF when U0 is 4V, I0, should more than 6uF be got;

V5 Correctional tube, igbt should be adopted, this pipe only needs voltage without the need to grid operating current, event drive current I3 is zero, but be biased in normal allowed band in order to what ensure gated transistor, need to add R1, R2 dividing potential drop control gate voltage at about 10 ~ 15V, the optional hundred megaohm resistance values of R1, make electric current be less than 0.003mA, power consumption is less than 1mW; R2 selects about 5 megaohms.If export 80V, R3 should select 17M Ω, the key of the design is to minimum by the power consumption control of Correctional tube.

Part III is reference voltage circuit (subscript 7X sequence number represents benchmark).Reference voltage both compares (subtracting each other) for output voltage and extracts error with it, again for partial circuit structure constant pressure source, constant-current source need to provide benchmark.The accuracy of reference voltage, stability are that whole circuit working is stable and crucial accurately.Poor in order to overcome conventional voltage stabilizing circuit temperature characterisitic, the high voltage precision of voltage regulation is not good, and power consumption is large, and reduce operating current and cause the problems such as poor stability, the design adopts constant-current source to control operating current, this not only makes voltage-stabiliser tube current stabilization, and then stablize its AC resistance, and be bordering on infinity because of the AC resistance of constant-current circuit, the mains fluctuations dividing potential drop that voltage-stabiliser tube obtains will be very little, the impact making reference voltage fluctuated by total voltage is very micro-: thus the operating current that significantly can reduce voltage-stabiliser tube to 1mA even below (now its internal resistance is still much smaller than constant-current source AC impedance), and utilize the characteristic that constant current flows through resistance generation constant voltage can obtain various different reference voltage easily, be more convenient for using voltage-stabiliser tube temperature performance preferably about 6V voltage.

The stable mechanism of circuit: when burst reason makes I72 ↑ → I73, I74 ↑ → UR74 ↑ → I71 ↑ → reference voltage slightly rise, but its ascensional range is much smaller than the rising level of I72*R72=UR72, make V72eb ↓, cause I72 ↓, circuit recovers stable.

Part IV is sampling (error extraction) circuit, this voltage regulation way adopts the voltage sampling in parallel with output voltage, get output voltage to compare with reference voltage, remove base value, extract error: the design by output voltage fluctuation be limited in rated voltage 1% ~ 3%, the conventional 10mA ~ 12mA of the current fluctuation of LED considers, in order to make control circui sensitivity reach preferable states, sampling should get whole amount.Namely sample with whole output voltage, but not dividing potential drop.

It is sample value and fiducial value are compared (subtracting each other) that error is extracted, and takes out difference and delivers to next stage circuit, produce the voltage that one is beneficial to the out-of-limit judgement of bound.Wherein type voltage regulation circuit output voltage and voltage-stabiliser tube or constant-current source is flow through the stable reference voltage that resistance produces to compare (subtracting each other), take out difference.

Part V is error amplifying circuit, and because error is direct current signal, its amplifying circuit will be unable to do without typical DC amplification circuit.The design to the control errors of LED voltage regulation type driving power with rated voltage 1% for basic consideration, namely the upper limit of 3V voltage is 3V, the upper limit of lower limit 2.97V, 10V voltage is 10V, lower limit is 9.9V; The upper limit that the upper limit of 80V voltage is 80V, lower limit is 79.2V, 100V voltage is 100V, lower limit is 99V; If low-voltage is difficult to control can be up to 3% control; Output voltage 1% fluctuation that prime detects by error amplifying circuit zooms into the voltage that next stage circuit can be monitored.For 3 ~ 10V circuit, one is limited by the restriction of supply voltage, multiplication factor, and two is that voltage regulation type bound difference is very little, and single-stage is amplified and is difficult to reach requirement (bound is difficult to obvious separation, judges), needs to arrange secondary and amplifies; The greatest problem of this part is, because whole control circuit working point is very low, very easily produces null offset, and when particularly having multistage amplification, the drift of prime can cause maximum error after rear class is amplified, and affects the precision even success or not of control circui.For head it off, adopt and compare amplifying circuit, to overcome the impact of null offset (common mode disturbances).

Part VI is upper and lower limit measuring and adjustation pipe (HF switch) control circuit.The voltage comparator that the overtension of the design or too low (bound) monitoring adopt comparison circuit to form.

The upper limit of corresponding output voltage or lower limit, after prime extracts error, error amplifying circuit can export a high voltage and a low voltage value, low voltage value lower control limit observation circuit saturation conduction, high-voltage value upper control limit observation circuit saturation conduction after amplifying.

The bound observation circuit that this comparison circuit is formed, essence is that one end of this circuit is set to reference edge, imposes self adaptation reference potential by the design relatively to the two-state circuit that pipe is formed, and the circuit other end is used for error voltage monitoring.When output voltage (error monitoring end) do not reach in limited time, reference edge is high potential, forms upper limit monitoring door; Once output voltage exceedes the upper limit, comparison circuit upset, reference edge is adjusted to electronegative potential at once, and comparison circuit becomes lower limit monitoring door; After this, after comparison circuit will wait until that output voltage drops in limited time, monitoring comparison circuit overturns again, reference edge is adjusted to high potential again, thus realizes the self adaptation of monitoring door.V10, V11 are relatively to pipe, V73 provides constant current benchmark for comparison circuit, V10 is made to obtain a reference voltage, when output voltage lower (monitoring perform pipe V6 do not have saturation conduction), this voltage is a high level, relatively to managing as left saturated (V10 is saturated), right cut-off (V11 cut-off), V6 remain off state, state that Correctional tube is in " open-minded ", output voltage is only had to rise, be added to after relatively this high level reference voltage being greater than to the rear voltage of error amplification of (V11) on the right side of pipe, relatively left cut-off (V10 cut-off), right saturated (V11 is saturated) are turned into tubulose state, V6 transfers saturation conduction state to, state that Correctional tube is in " shutoff ", C2 is to load discharge, and output voltage declines by electric discharge exponential curve, simultaneously, monitoring performs the saturation conduction of pipe V6, make relatively to drop to a low value to reference voltage on the left of pipe by V7 clamper, even if output voltage declines (more than lower limit), relatively left cut-off is still kept to pipe, right saturation condition is constant, until output voltage drops to the lower limit of permission, deliver to after relatively this low value reference voltage being less than to the rear voltage of error amplification of (V11) on the right side of pipe, relatively tubulose state is turned into again left saturated, right cut-off, V6 transfers cut-off to again, state that Correctional tube is in again " open-minded ", C1 charges rapidly to C2 and to load supplying, output voltage rises fast.So, circuit realiration circulation-----resonant mode work.

Part VII is overcurrent, overvoltage, overtemperature protection (subscript 8 start sequence number represent protection).For preventing output circuit short circuit or power supply overvoltage out of control or temperature overheating, design has arranged short circuit (overcurrent) and overvoltage, overheating protection circuit.Simply, power loss is little for the overvoltage be made up of comparison circuit and overheating protection circuit.The short-circuit protection circuit be made up of constant-current source is connected in output loop and limits output current; during for ensureing normal, this loop power consumption is low as far as possible; be provided with bypass and access control (the monitoring output voltage of this circuit; when output reaches 50%U0, this circuit is bypassed; when output is lower than this circuit access during 50%U0), this technology also achieves circuit self-recoverage after short circuit Failure elimination simultaneously.

V801 ~ V805 be overvoltage protection, be made up of comparison circuit.V801, V804 constant-current source produces on R801, R807 stablizes pressure drop, when output voltage is less than overpressure value, V802, V803 relatively to pipe for the right cut-off of left conducting, when output voltage is greater than overvoltage limit value, V802, V803 are relatively to managing as the left cut-off of right conducting, and V803 collector electrode exports high potential;

V806 ~ V810 is overtemperature protection, is also made up of comparison circuit.V807, V810 constant-current source produces on R809, R814 stablizes pressure drop, when temperature is lower than (negative tempperature coefficient thermistor R814 and R815 presents higher resistance value) during limit value, V808, V809 are relatively to managing as the right cut-off of left conducting, when temperature is higher than limit value (R814 and R815 resistance step-down, the upper voltage of R815 reduces, I813 reduces, R814 power on be pressed into doubly reduce, V810 collection penetrates a voltage and significantly rises), V808, V809 relatively transfer the left cut-off of right conducting to pipe, and V809 collector electrode exports high potential; V800 is that overvoltage and overtemperature protection perform pipe, and its collector electrode is connected to Correctional tube base stage, when V803 overvoltage or V809 overtemperature protection action (saturated), will control V800 saturation conduction, and it directly controls Correctional tube stopping again, thus output voltage is declined.

V811 ~ V817 is short circuit overcurrent protection.V811 and V812 and R817, R818 form output current limiting, when output short-circuit, circuit by current limliting in the value that V812 and R817 determines (if V811=0.5V, R817=17, electric current will be limited in 0.25/17 ≈ 15mA), V812 both end voltage be circuit output voltage, thus operating circuit has normal voltage supply and be not shorted when guaranteeing load short circuits, circuital current does not transfinite; V813 ~ V817 forms output monitoring and current-limiting circuit access, exits control, when output voltage is greater than definite value (as 80%U0), and V816, V815, V814, V813 saturation conduction, V811, V812 and R817, R818 are bypassed short circuit; When output voltage is less than definite value (as 70%U0), V816 ends and control V815, V814, V813 cut-off, and V811, V812, R817 are connected in series into output loop, output current is limited, for reducing power consumption, V813, V814 adopt multiple tube, to reduce driving (flowing through R819's) power consumption.

Overvoltage overheating protection circuit is connected in parallel on and exports positive and negative; Short circuit overcurrent limit circuit is connected in series with load, its voltage monitoring is in parallel with load.

2. duplicate supply technical descriptioon, consider that each branch power consumption should control at 0.2 ~ 0.5mW, so, 3V output voltage operating circuit should control 0.1 ~ 0.2mA, 10V output voltage operating current should control 0.02 ~ 0.05mA, 50V output voltage operating current should 0.004 ~ 0.01mA, 100V output voltage operating current should control 0.002 ~ 0.005mA, the work of 200V output voltage should at 0.001 ~ 0.003mA, 300V output voltage operating current should at 0.0004 ~ 0.002mA.Clearly, for below 10V voltage, such operating current circuit still can steady operation, select also impact little on device; But for high output voltage, the operating current of each branch road is too little and can make that circuit working is unstable, device is selected also can be restricted.Solution to this problem adopts the design of duplicate supply-i.e. inner low-voltage arranging a 3-5V of driving power, control circuit is operated in 3 ~ 5V, does not contact with output voltage except voltage sampling, the LED drive power that any high voltage exports obtains reference power supply by this working power, powers to operating circuit, thus the reference voltage power consumption of whole driving power and whole circuit power consumption are declined to a great extent, the total operating current of circuit controls at 3 ~ 2mA, and overall power can be controlled in below 10mW, even reaches the target of 5mW.

And output voltage can be selected arbitrarily as required, except sampling, (power consumption of this branch road should be limited in about 1mW) output circuit is without work branch, specifically see the working power part of schematic diagram, i.e. and the latter half except load of schematic diagram.This voltage should be selected according to output voltage height, exports highly should select near 5V working power to more than 100V, and output voltage is optional near 3V working power lower than 30V.

If output voltage is lower, can circuit be simplified, cancel working power, directly replace with voltage-stabiliser tube, please refer to accompanying drawing 3.In figure, schematic diagram does not indicate overvoltage, overcurrent, overtemperature protection.

If export in, low voltage range, please refer to the simplification circuit of accompanying drawing 4.

The beneficial effects of the utility model are:

1. energy-conserving and environment-protective, this power supply conversion efficiency is high, because bridge heap adopts Schottky diode, two to be adopt adjust pipe, the topological structure of duplicate supply, reference power supply of insulated gate bipolar field effect transistor to adopt that constant-current source and constant voltage power supply circuit build, bound detection control circuit adopts comparator, error amplifying circuit to adopt the designs of comparison circuit, resonant mode high frequency switch power, regulation output voltage is carried out with duty ratio and frequency co-variation, as above etc. the employing of scheme, make the power consumption of circuit self extremely low, efficiency is very high, and temperature drift is little, stability is high.

2. small volume, facilitate integrated, can meet and apply widely, eliminate the devices such as bulky transformer, inductance, the especially employing of duplicate supply, operating circuit uses 3 ~ 5V voltage, the LED drive power of different output voltage only need adjust a small amount of resistance (external or loong shunt), make internal pull-up circuit curable, thus integrated (IC) change can be realized more easily, suitable for mass production.

3. Electro Magnetic Compatibility is good, owing to not having frequency-conversion circuit, does not have high tension apparatus, does not have the inductive load etc. of inductance, and its High-frequency Interference is little, conveniently applies for the Safety Approvals such as EMC, FCC.

The above, be only embodiment of the present utility model, but protection range of the present utility model is not limited thereto, and any change of expecting without creative work or replacement, all should be encompassed within protection range of the present utility model.Therefore, the protection range that protection range of the present utility model should limit with claims is as the criterion.

Claims (8)

1. the noninductive high frequency switch power of transless of a LED illumination driving; it is characterized in that: comprise seven circuit; Part I is current rectifying and wave filtering circuit; Part II is adjustment executive circuit; Part III is reference voltage circuit; Part IV is sample circuit; Part V is error amplifying circuit; Part VI is that upper and lower limit detects and ON-OFF control circuit; Part VII is overcurrent, overvoltage, overheating protection circuit, and described current rectifying and wave filtering circuit is piled by V1 ~ V4 bridge and filter capacitor C1 forms.

2. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: described adjustment executive circuit is installed between current rectifying and wave filtering circuit and ON-OFF control circuit.

3. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: one end and the current rectifying and wave filtering circuit of described ON-OFF control circuit electrically connect.

4. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: the output of described reference voltage circuit and the input of sample circuit electrically connect.

5. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, it is characterized in that: the two ends of described current rectifying and wave filtering circuit are provided with load, described adjustment executive circuit is installed on load one end.

6. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: the output of described error amplifying circuit detects with upper and lower limit and the input of ON-OFF control circuit is connected.

7. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: the output of described sample circuit is connected with the input of error amplifying circuit.

8. the noninductive high frequency switch power of transless of LED illumination driving according to claim 1, is characterized in that: the working power of described reference voltage circuit is 3-5V.