CN203072212U - A LED light-adjusting power supply - Google Patents

Abstract

Provided is a LED light-adjusting power supply which comprises a power converting circuit. The power converting circuit comprises a single-stage flyback switch control circuit. The LED light-adjusting power supply also comprises a phase detecting circuit used for detecting the phase-cut angle or the conduction angle of the waveform of a signal outputted from the power converting circuit. The phase detecting circuit comprises a diode, a capacitor, and a voltage-regulator tube. The anode of the diode is electrically connected with the output end of the power converting circuit, while the cathode of the diode is connected with the anode of the capacitor. In addition, the anode of the capacitor is electrically connected with anode of the voltage-regulator tube. The cathode of the diode, the cathode of the capacitor, and the cathode of the voltage-regulator tube are connected with ground. By the detection of the phase detecting circuit, the output current of a DC/DC converting circuit can be changed with the change of a light adjuster in order that the brightness of a LED lamp can be adjusted. In addition, filament lamps and halogen lamps can be directly replaced because of the presence of the LED light-adjusting power supply. Therefore, installing working time and cost are reduced and the presence of the LED light-adjusting power supply accords with the using habit of a user.

Description

A kind of LED light modulation power supply

Technical field

The utility model relates to a kind of LED power supply, particularly a kind of LED light modulation power supply.

Background technology

The LED illumination is progressively replacing conventional light source, as incandescent lamp, Halogen lamp LED etc., and these conventional light source can be used with a kind of dimmer, the brightness that makes incandescent lamp or Halogen lamp LED by secretly to bright or by bright to dark variation, if therefore the LED lamp also can be followed this dimmer compatibility, the user is replacing incandescent lamp with the LED lamp like this, during Halogen lamp LED, just needn't change simultaneously dimmer or and dimmer and LED lamp between connection line, thereby saving installation cost, the use habit that also more meets simultaneously the user, and traditional dimmers mainly contains following two types dimmer according to the difference of the electronic technology that adopts.A kind of is preceding phase shift dimmer, claims controllable silicon dimmer again, adopts bidirectional triode thyristor to control as electronic switch and opens or cut off the electricity supply to the power supply of load.Another kind is back phase shift dimmer, and it adopts field effect transistor or insulated gate bipolar triode to control as electronic switch and opens or cut off the electricity supply to the power supply of load.

Fig. 1 is the fundamental diagram that a kind of preceding phase shift dimmer is regulated incandescent lamp or Halogen lamp LED brightness, and it is a kind of circuit theory diagrams that controllable silicon is regulated incandescent lamp brightness in the prior art.In this circuit, power supply is carried out forward position copped wave.Its operation principle is when firm Closing Switch, the resistance value maximum of potentiometer RES3, charging interval to capacitor C is the longest, just can reach the cut-in voltage of the diac DB3 of bidirectional triode thyristor TRIAC, the ON time of bidirectional triode thyristor TRIAC is the shortest, the power that incandescent lamp obtains is also just minimum, and brightness is also just the darkest.Rotational potentiometer RES3 gradually, its resistance value diminishes, and the ON time of bidirectional triode thyristor TRIAC is elongated, and it is big that the power that incandescent lamp obtains becomes, and brightness has also just improved.So just can realize the stepless continuous light modulation simple and reliablely.

Owing to can directly under civil power, work than incandescent lamp/Halogen lamp LED, the LED lamp generally needs the constant current DC driven, therefore, if keep existing controllable silicon light modulation circuit or back phase shift light adjusting circuit constant and directly replace incandescent lamp/Halogen lamp LED with the LED lamp, a change-over circuit must be arranged, be the LED drive current of correspondence with the waveform transformation of controllable silicon or back phase shift light adjusting circuit output, make the drive current of LED along with the big or small corresponding change of the output waveform conducting angle of controllable silicon or back phase shift light adjusting circuit, the brightness of such LED lamp could corresponding change.

The utility model content

In view of this, be necessary to provide a kind of LED light adjusting circuit, to realize the step-less adjustment of LED lamp brightness.

A kind of LED light modulation power supply, it comprises a circuit for power conversion.This circuit for power conversion comprises an anti-energizing switch control circuit of single-stage.Described LED light modulation power supply also comprises one for detection of the cut angle of the signal output waveform of described circuit for power conversion or the phase detecting circuit of the angle of flow.Described phase detecting circuit comprises a diode, an electric capacity, and a voltage-stabiliser tube.The anode of described diode and the output of circuit for power conversion electrically connect, and negative electrode is connected with the positive pole of electric capacity, and the anodal while of electric capacity electrically connects the negative electrode of described diode, the negative pole of electric capacity, and the minus earth of voltage-stabiliser tube with the anode of voltage-stabiliser tube.

In sum, by the detection of described phase detecting circuit, the output current of DC/DC change-over circuit is changed along with the variation of dimmer, thereby the brightness of adjusting the LED lamp change.Because incandescent lamp, Halogen lamp LED etc. can be directly replaced in the existence of this LED light modulation power supply, reduce installation work-hour and expense simultaneously, meet user's use habit.

Description of drawings

Below in conjunction with accompanying drawing embodiment of the present utility model is described, wherein:

Fig. 1 is the circuit theory diagrams of a kind of LED lamp light modulation power supply of the prior art.

The circuit theory diagrams of a kind of LED light modulation power supply that Fig. 2 provides for the utility model.

Fig. 3 is the circuit diagram of first embodiment of the LED light modulation power supply of Fig. 1.

Fig. 4 is the comparison of wave shape figure that the circuit diagram of Fig. 3 is ordered at a point, b.

Fig. 5 is the waveform that the circuit diagram of Fig. 3 is ordered at a point, c.

Fig. 6 is the waveform that the circuit diagram of Fig. 3 is ordered at a point, d.

Fig. 7 is that the circuit diagram of Fig. 3 is at the comparison diagram of the output waveform of d point and arithmetic element.

Embodiment

Below based on accompanying drawing specific embodiment of the utility model is further elaborated.Should be appreciated that specific embodiment described herein only as embodiment, and be not used in restriction protection range of the present utility model.

See also Fig. 2, it is the circuit theory diagrams of a kind of LEDlight adjusting circuit 100 provided by the utility model.Described LEDlight adjusting circuit 100 comprises 10, one AC/DC change-over circuits 11 that electrically connect with this dimmer 10 of a dimmer, and a brightness adjustmentcontrol output circuit 12 that electrically connects with this AC/DC change-over circuit 11.What can expect certainly is, is to be electrically connected on the output of brightness adjustmentcontrol output circuit 12 as the LED lamp (not shown) of load.

Described dimmer 10 is electronic light modulator, and it mainly acts on and is controlled rectification, to adjust the different brightness of light, namely by reducing or increase the light output of the varying strength that light that RMS voltage impels average power produces.Described dimmer 10 can be a kind of of phase dimmer or back phase shift dimmer that move forward.The phase shift dimmer is called controllable silicon or thyristor again before described, especially, adopts bidirectional triode thyristor to come opening and the power supply of cutting off the electricity supply to load of control circuit.Described back transposition dimmer adopts field effect transistor or insulated gate bipolar triode to be used as electronic switch and controls and lead the power supply of can or cut off the electricity supply to load.In the present embodiment, described dimmer 10 is bidirectional triode thyristor, and it is prior art, repeats no more.

The effect of described AC/DC change-over circuit 11 is that it is that the LED lamp uses for load that alternating current is converted to direct current, because the employed electric current of LED lamp is necessary for direct current.This AC/DC change-over circuit 11 comprises a filter circuit 111 that electrically connects with this dimmer 10, a rectification circuit 112 that electrically connects with this filter circuit 11, a circuit of power factor correction 113 that is electrical connected with this rectification circuit 112, a circuit for power conversion 114 that is electrical connected with this circuit of power factor correction 113, and a feedback circuit 115 that is electrically connected between this circuit for power conversion 114 and the circuit of power factor correction 113.

Described filter circuit 111 is used for the impact of filtering clutter and antisurge, and to satisfy electromagnetic compatibility requirements, it generally is made up of reactance component, as at load resistance two ends shunt capacitor, or with the load series reactor, and by electric capacity, inductance is formed the various compound filter circuit that forms.As shown in Figure 3, be a kind of filter circuit 111 provided by the utility model, it is a kind of active filter circuit of the prior art.

Described rectification circuit 112 as shown in Figure 3, is a kind of bridge rectifier, and the circuit that it utilizes the unidirectional conduction of diode to carry out rectification is to change alternating current into direct current.Bridge rectifier utilizes four diodes, and butt joint in twos.When just half part of input sine wave, two conductings in described four diodes, thus export half positive sine wave.When negative half part of input sine wave, two conductings in addition in described four diodes.Because this two is reversal connection by all means, so output also will be sinusoidal wave just half part, thereby can reduce electric quantity loss.

The input signal that described circuit of power factor correction 113 is used for according to feedback circuit 115 is adjusted the output of circuit for power conversion 114.Power factor refers to the relation between effective power and the total power consumption (apparent power), and just effective power is divided by the ratio of total power consumption (apparent power).Basically power factor (PF) can be weighed the degree that electric power is used effectively, and when the power factor (PF) value is more big, it is more high to represent its electric power utilance.Therefore, in order to improve the capability correction factor of power supply, general all power supplys all installation power factor correcting circuit, repeat no more so it is prior art to improve the conversion efficiency of power supply.

Described circuit for power conversion 114 is used for high voltage direct current is converted into the low-voltage direct that is applicable to brightness adjustment control output circuit 12.For adapting with described brightness adjustmentcontrol output circuit 12, described circuit for power conversion 114 also comprises an anti-energizing switch control circuit 1141 of single-stage, and it can instead swash high pfc circuit for a single-stage.The anti-energizing switch control circuit 1141 of this single-stage is to provide energy at switch transistor T blocking interval transformer to output capacitor and load, and sense of current is single in the power supply process.Because the anti-energizing switch control circuit 1141 of described single-stage is single-stages, make that waveform that a in the entire circuit orders is identical with the output waveform of dimmer 10, what change may only be the size of amplitude, we can say that also waveform that a is ordered and the output waveform of dimmer 10 are equal proportion convergent-divergents.Described circuit for power conversion 114 comprises a transformer winding 1142, the input of this transformer winding 1142 is opposite with the phase place of output, the turn ratio of the corresponding line of amplitude and input and output resistance is proportional, thereby provides a suitable low-voltage for described brightness adjustmentcontrol output circuit 12.

Described feedback circuit 115 is electrically connected between circuit for power conversion 114 and the circuit of power factor correction 113, feeds back to circuit of power factor correction 113 with the output signal with circuit for power conversion 114.This circuit of power factor correction 113 is by adjusting the output signal of described circuit for power conversion 114 after relatively again with part or all of the output signal of circuit for power conversion 114, for example strengthens the output signal of circuit for power conversion 114 or weakens the output signal of circuit for power conversion 114.Through correction repeatedly, the output signal of circuit for power conversion 114 is just exported to brightness adjustmentcontrol output circuit 12.

Need to prove, the circuit diagram of being formed by actual electronic devices and components of described filter circuit 111, rectification circuit 112, circuit of power factor correction 113, circuit for power conversion 114, feedback circuit 115, as shown in Figure 2, be all prior art, this repeats no more again for its composition structure and operation principle.In addition, be understandable that above-mentioned each functional circuit all has input and output, each functional circuit all electrically connects the output of previous functional circuit and the input of a back functional circuit simultaneously.

Described brightness adjustmentcontrol output circuit 12 comprises a DC/DC change-over circuit 121 that is connected with the output electric property of described circuit for power conversion 114, a phase detecting circuit 122 that is connected with the output electric property of described circuit for power conversion 114,123, one arithmetic elements 124 that electrically connect with this shaping circuit 123 of shaping circuit that electrically connect with this phase detecting circuit 122.The input of the output of described arithmetic element 124 and DC/DC change-over circuit 121 electrically connects.

Described DC/DC change-over circuit 121 is a kind of switching power source chip, it utilizes the characteristic of the energy storage of electric capacity, inductance, (MOSFET etc.) carry out the action of HF switch by gate-controlled switch, with the input electrical power storage in electric capacity (sense) lining, when switch disconnects, electric energy discharges to load again, and energy is provided.The power of its output or the ability of voltage and duty ratio (by the ratio in cycle of switch conduction time and whole switch) are relevant.This DC/DC change-over circuit 121 can be used for boosting and step-down.In the utility model, described DC/DC change-over circuit 121 will be exported electric current that the constant and width of amplitude modulated by described impulse wave to drive load LED lamp.When 10 pairs of size of current of dimmer are adjusted, this DC/DC change-over circuit 121 directly detects the adjustment less than this dimmer 10, thereby also be difficult to the size of its output current of control, and then can not control the size of the input current of LED lamp, the feasible brightness that can not control the LED lamp.Therefore the described phase detecting circuit 122 of needs detects the output of dimmer 10, i.e. cut angle or the angle of flow of dimmer 10 outputs.

Whether described phase detecting circuit 122 is subjected to the influence that dimmer 10 is adjusted electric current for detection of the current waveform of described circuit for power conversion 114 outputs.When dimmer 10 reduces output voltage or increases output voltage, need this phase detecting circuit 122 to detect the lifting of this output voltage, and should detected signal after shaping circuit 123 arrangements, be input in the arithmetic element 124, after this arithmetic element 124 is handled, output pulse signal is modulating the output current of described DC/DC change-over circuit 121, thereby the brightness that drives load LED lamp changes.Described phase detecting circuit 122 comprises a diode D9,16, one voltage-stabiliser tube D11 of a capacitor C, and at least one impedance.The high level end of the output of the anode of described diode D9 and circuit for power conversion 114 electrically connects, and negative electrode is connected with the positive pole of capacitor C 16, and the anodal while of capacitor C 16 electrically connects with the anode of voltage-stabiliser tube D11.The negative pole of the negative electrode of described diode C16, capacitor C 16, and the low level end of the output of the negative electrode of voltage-stabiliser tube D11 and circuit for power conversion 114 electrically connects or ground connection.Described at least one impedance comprises four resistance R 23, R24, R25 and R26 in the present embodiment.Described resistance R 23 is connected between diode D9 and the capacitor C 16, resistance R 24 is connected in parallel between diode D9 and the capacitor C 16, resistance R 25 is connected between capacitor C 16 and the voltage-stabiliser tube D11, and resistance R 26 is connected between the high level output of voltage-stabiliser tube D11 and phase detecting circuit 122.The operation principle of this phase detecting circuit 122 is as described below.

As shown in Figure 4, oscillogram and the comparison of ordering at a point and b for circuit for power conversion 114, as can be seen after dimmer 10 is cut ripple, it still is 2 times of all-waves to the load rating frequency " steamed bun ripples " that a selects waveform, obviously, the waveform at this a point place can not directly be loaded on the load LED lamp, because LED lamp needs is constant-current supply.Because the Transformer Winding Lp1 of circuit for power conversion 114 is opposite with the Ls phase place, the input and output tie point of phase detecting circuit 122 and circuit for power conversion 114 is that b point waveform and a point waveform are with anti-phase.Simultaneously when the single-stage revertive control switching tube closed condition of circuit for power conversion 114, b point differs the high voltage of 0.7V for forward and with the output voltage of this phase detecting circuit 122.But, diode D9 isolates or has blocked the forward voltage that b is ordered, formed pulse when capacitor C 16 has played the switching tube Q1 switch of eliminating in the circuit for power conversion 114 simultaneously, thereby stablized the effect of c point voltage, thereby obtain the waveform that c is ordered, as shown in Figure 5, it is still with a point waveform similarity but anti-phase.Suppose that voltage-stabiliser tube D11 loop of living in is in when electrically disconnecting state, the voltage that R26, R25, the R23 voltage ratio by three resistance makes d order will be raised in proportion, i.e. Ud=Uc+Uout* (R23+R24)/(R23+R25+R26)

Wherein: Ud is the voltage at voltage-stabiliser tube two ends;

Uc is the voltage at electric capacity two ends when R25 disconnects;

Uout is the output voltage of described phase detecting circuit.

But because the existence of voltage-stabiliser tube D11, namely this voltage-stabiliser tube D7 loop of living in is in when electrically connecting, and this voltage-stabiliser tube D7 reverse-conducting makes that the voltage that surpasses voltage-stabiliser tube D11 is the voltage stabilizing value that voltage that d is ordered is limited in voltage-stabiliser tube D11.And the voltage of ordering as b is when being negative sense, and this voltage-stabiliser tube D7 forward conduction, the output voltage of this phase detecting circuit 122 are that the forward voltage drop that voltage that d is ordered then is limited in voltage-stabiliser tube D11 is about about 0.7V, thereby obtain the waveform that d is ordered, as shown in Figure 6.Here " pact " refers to that this forward voltage drop has fluctuating, rather than an absolute constant value owing to the characteristic of circuit existence itself.As can be seen from the figure 6, through the effect of this phase detecting circuit 122, the waveform of output becomes square wave, namely becomes arithmetic element 124 needed phase angle detection signals, thereby is beneficial to the adjustment conversion of subsequent conditioning circuit.Need to prove, because the anti-energizing switch control circuit 1141 of single-stage of circuit for power conversion 114 is circuit of reversed excitation, it only is that phase place is opposite that the waveform that b is ordered is compared with the waveform that a is ordered, thereby can be so that the output signal of this phase detecting circuit 122 correctly reflects input and the output of circuit for power conversion 114, and then can accurately be adjusted the output signal of DC/DC change-over circuit 121 by shaping circuit 123 and arithmetic element 124.

Described shaping circuit 123 is used for putting in order the signal waveform from phase detecting circuit 122, and the signal waveform after will putting in order is input to arithmetic element 124.As can be seen from Figure 6, also not strict square wave from described phase detecting circuit 122 resulting waveforms, this waveform is organized into the square wave of strictness through the shaping of this shaping circuit 123.

The negative electrode of described arithmetic element 124 and voltage-stabiliser tube D11 electrically connects to receive the output signal of voltage-stabiliser tube D11, behind the information decoding with the cut angle that comprises waveform of shaping circuit 123 or the angle of flow, export a series of impulse waves and pass in the DC/DC change-over circuit 121, the cut angle of the width of impulse wave and described waveform or the amplitude of the angle of flow are proportional, as shown in Figure 7.When DC/DC change-over circuit 121 receives and according to the pulse signal of this arithmetic element 124, adjusts the size of its output current, and then make the brightness of LED lamp change, reach the effect of light modulation.Described arithmetic element 124 can be single chip machine controlling circuit, also can other device, and as central processing unit, or the computing circuit of being formed by other electronic components such as operational amplifier.

The circuit diagram of being formed by actual electronic devices and components of described DC/DC change-over circuit 121, shaping circuit 123 and arithmetic element 124, as shown in Figure 2, it is all prior art, and it forms structure and operation principle, and this repeats no more again.

In sum, by the detection of described phase detecting circuit 122, the output current of DC/DC change-over circuit 121 is changed along with the variation of dimmer 10, thereby the brightness of adjusting the LED lamp change.Because incandescent lamp, Halogen lamp LED etc. can be directly replaced in the existence of this LED lightmodulation power supply 100, reduce installation work-hour and expense simultaneously, meet user's use habit.

The various parts that illustrated can encapsulate in any way.For example, comprise that the parts of single-chip microcomputer can be encapsulated in the single integrated circuit with other active and passive component, be encapsulated in one group of integrated circuit with other active and passive component that perhaps active and passive component is encapsulated in the upright circuit of a component with other.

The whole various circuit that illustrated can by arbitrarily or whole combinations interconnect use.

The parts of having discussed, step, benefit and advantage only are illustrative.They and relevant discussion thereof all are not intended to limit by any way protection range.Multiple other execution mode also can expect, comprise have still less, other and/or different parts, step, characteristic, benefit and and the execution mode of advantage.Described parts and step also can be arranged and sort by different modes.

Similar " be used for ... device " when comprising the structure and material that illustrated and their equivalent with in the claims the time.Similarly, phrase " be used for ... step " when comprising the behavior that has illustrated and be equal to behavior with in the claims the time.There are not these phrases to mean that then this claim is not limited to arbitrarily corresponding structure, material or behavior or its equivalents.

The content of having stated or having illustrated is not intended to make arbitrarily parts, step, characteristic, target, benefit, advantage or is proprietary for the content that the public is equal to, and whether this and they are mentioned irrelevant in the claims.

The above only is preferred embodiment of the present utility model; not in order to limit the utility model; all interior any modifications of doing in spirit of the present utility model and principle, be equal to and replace and improvement etc., all should be included in protection range of the present utility model in.

Claims (10)

1. LED light modulation power supply, it is characterized in that, this LED light modulation power supply comprises a circuit for power conversion, described circuit for power conversion comprises an anti-energizing switch control circuit of single-stage, described LED light modulation power supply also comprises one for detection of the phase detecting circuit of the signal output waveform of described circuit for power conversion, described phase detecting circuit comprises a diode, an electric capacity, and voltage-stabiliser tube, the anode of described diode and the output of circuit for power conversion electrically connect, and negative electrode is connected with the positive pole of electric capacity, and the anodal while of electric capacity electrically connects with the anode of voltage-stabiliser tube, the negative electrode of described diode, the negative pole of electric capacity, and the minus earth of voltage-stabiliser tube.

2. LED light modulation power supply as claimed in claim 1, it is characterized in that: described phase detecting circuit comprises four resistance, between resistance R 23 series diode and the electric capacity, a resistance R 24 is connected in parallel between diode and the electric capacity, a resistance R 25 is connected between electric capacity and the voltage-stabiliser tube, and a resistance R 26 is connected between voltage-stabiliser tube and the load.

3. LED light modulation power supply as claimed in claim 2 is characterized in that: when described voltage-stabiliser tube loop of living in is in when electrically disconnecting state, the relation of the magnitude of voltage at these voltage-stabiliser tube two ends and described four resistance is as follows:

Ud＝Uc+Uout*(R23+R24)/(R23+R25+R26)

Wherein: Ud is the voltage at voltage-stabiliser tube two ends;

Uc is the voltage at electric capacity two ends when disconnecting at resistance R 25 places;

Uout is the output voltage of described phase detecting circuit.

4. LED light modulation power supply as claimed in claim 1 is characterized in that: when described voltage-stabiliser tube loop of living in is in when electrically connecting, the forward voltage drop at this voltage-stabiliser tube reverse-conducting and two ends equals the specified voltage stabilizing value of this voltage-stabiliser tube.

5. LED light modulation power supply as claimed in claim 1 is characterized in that: when described voltage-stabiliser tube loop of living in is in when electrically connecting, the negative sense pressure drop at this voltage-stabiliser tube forward conduction and two ends is about 0.7V.

6. LED light modulation power supply as claimed in claim 1, it is characterized in that: described LED light modulation power supply comprises an arithmetic element.

7. LED light modulation power supply as claimed in claim 6, it is characterized in that: described arithmetic element is a single-chip microcomputer, its according to the output signal of described voltage-stabiliser tube to export specified impulse wave.

8. LED light modulation power supply as claimed in claim 7, it is characterized in that: described LED light modulation power supply also comprises a shaping circuit, this shaping circuit is arranged between described phase detecting circuit and the arithmetic element, and this shaping circuit is used for and will be input to single-chip microcomputer after the signal waveform arrangement from phase detecting circuit.

9. LED light modulation power supply as claimed in claim 1 is characterized in that: the anti-energizing switch control circuit of described single-stage is that single-stage instead swashs high pfc circuit.

10. LED light modulation power supply as claimed in claim 1, it is characterized in that: described circuit for power conversion comprises a transformer winding, and the input of this transformer winding is opposite with the phase place of output, and the turn ratio of the corresponding line resistance of amplitude and input and output is proportional.

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