Apparatus and method for simultaneously adjusting brightness and color temperature, and LED lamp

An apparatus and method for simultaneously adjusting brightness and color temperature, and an LED lamp. The apparatus includes a phase control dimmer, a rectification module, a phase detection module, a current control module and an LED module. Cutting the phase of an input alternating current by the phase control dimmer changes the effective voltage of the alternating current, then the cut alternating current is rectified by the rectification module and output to the LED module, thus adjusting the brightness of the LED module; information about the cut phase is detected by the phase detection module and a current control signal is output to a current control module according to the cut phase information, and the current control module controls change in the brightness ratio of mixed colors of the LED module according to the current control signal and adjusts the color temperature of the LED module.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a national stage application of PCT Patent Application No. PCT/CN2018/088365, filed on 25 May 2018, which claims priority to Chinese Patent Application No. 201710795203.8, filed on 6 Sep. 2017, the content of all of which is incorporated herein by reference.

FIELD

The present invention relates to the field of LED lightning, and more particularly, to an apparatus and a method for simultaneously adjusting brightness and color temperature, and a led lamp.

BACKGROUND

Although brightness and a color temperature are two irrelevant physical characters, a human eye will have different perceptions when receiving brightness and color temperatures of different LED lights, thus matching different brightness and color temperatures will obtain a plurality of different visual effects. However, in the prior art, when it is needed to achieve adjusting the brightness and the color temperature of an LED at a same time, there are still a plurality of aspects to be improved. For example, a method mentioned in CN201410729730.5 requires a key switch to select the color temperature, a triac dimmer to adjust the brightness, and only two types of the color temperature can be selected; also in a method described in CN201410240336.5, although the color temperature can be changed continuously, an adjustment depth is limited, and a bypass circuit has greatly increased a system power consumption.

Therefore, the current technology needs to be improved and developed.

SUMMARY

According to the above described defects, the purpose of the present invention is providing an apparatus and a method for simultaneously adjusting the brightness and the color temperature, and a led lamp, which changes the brightness of an LED module by a phase controlled dimmer cutting a phase of an input alternating current (AC), while at a same time, outputting a current control signal according to a phase cutting information before controlling a mixed brightness ratio of the LED module and achieving a synchronous adjustment for the color temperature, having a control circuit simple and a range wide of adjusting the color temperature, achieving a synchronous adjustment of the brightness and the color temperature without increasing an additional power consumption.

A technical solution of the present invention to solve the technical problems is as follows:

an apparatus for simultaneously adjusting brightness and a color temperature, wherein comprising a phase control dimmer, a rectification module, a phase detection module, a current control module and an LED module; changing an effective voltage of an alternating current by the phase control dimmer cutting a phase of an input alternating current, and rectifying the alternating current after being cut before outputting to the LED module by the rectification module, to adjust a brightness of the LED module; detecting a phase information after being cut through the phase detection module, and outputting a current control signal to the current control module according to the phase information after being cut, the current control module controls a change of a mixed color brightness proportion of the LED module according to the current control signal, to adjust a color temperature of the LED module.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the phase detection module comprises a voltage sampling unit, a comparison unit, a timer, an arithmetic logic unit and a control signal converter; sampling an output voltage of the rectification module by the voltage sampling unit and setting a voltage detection threshold; comparing an output voltage of the rectification module to the voltage detection threshold by the comparison unit, before outputting an level signal correspondingly; counting and outputting a timing value by the timer, according to the level output by the comparison unit; calculating a current value of the LED module by the arithmetic logic unit according to the timing value; outputting a current control signal correspondingly to the LED module by the control signal converter according to the current value.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the current control module comprises a first current control unit and a second current control unit; the LED module comprises a first LED lamps string and a second LED lamps string having the color temperature different; the arithmetic logic unit calculates respectively a current of the first LED lamps string and a current of the second LED lamps string according to the timing value, before converting into a first current control signal and a second current control signal by the control signal converter; the first current control unit and the second current control unit controls respectively a current in the first LED lamps string and a current in the second LED lamps string according to the first current control signal and the second current control signal, and controls the mixed color brightness proportion of the first LED lamp string and the second LED lamps string, to adjust the color temperature of the LED module.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the comparison unit outputs a first level, when the output voltage of the rectification module is less than the voltage detection threshold; the comparison unit outputs a second level, when the output voltage of the rectification module is greater than the voltage detection threshold; the comparison unit outputs a second level; when an output level of the comparison unit changes from the second level to the first level, the timer is cleared before starting to count, and when the output level of the comparison unit changes from the first level to the second level, the timer stops counting and outputs the timing value.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the voltage sampling unit comprises a first resistor, a second resistor and a first power source, one end of the first resistor connects to an input terminal of the rectification module, another end of the first resistor connects to one end of the second resistor and the comparison unit; another end of the second resistor connects to a negative electrode of the first power source and ground; a positive electrode of the first power source connects to the comparison unit; a voltage output from the first power source is the voltage detection threshold.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the comparison unit comprises a comparator, a non-inverting input terminal of the comparator connects to another end of the first resistor, an inverting input terminal of the comparator connects to the positive electrode of the first power source, and an output terminal of the comparator connects to an input terminal of the timer.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the first current control unit comprises a first operational amplifier, a first MOS transistor, and a third resistor; the second current control unit comprises a second operational amplifier, a second MOS transistor, and a fourth resistor; a first input terminal of the first operational amplifier connects to a first output terminal of the control signal converter, a second input terminal of the first operational amplifier connects to a source of the first MOS transistor, and gets grounded through the third resistor; an output terminal of the first operational amplifier connects to a gate of the first MOS transistor; a drain of the first MOS transistor connects to a negative electrode of the first LED lamps string;

a first input terminal of the second operational amplifier connects to a second output terminal of the control signal converter, a second input terminal of the second operational amplifier connects to a source of the second MOS transistor and gets grounded through the fourth resistor, an output terminal of the second operational amplifier connects to a gate of the second MOS transistor; a drain of the second MOS transistor connects to a negative electrode of the second LED string.

The apparatus for simultaneously adjusting the brightness and the color temperature, wherein the first current control unit comprises a third MOS transistor; the second current control unit comprises a fourth MOS transistor; a gate of the third MOS transistor connects to a first output terminal of the control signal converter, and a source of the third MOS transistor gets grounded, a drain of the third MOS transistor connects to the negative electrode of the first LED lamps string; a gate of the fourth MOS transistor connects to a second output terminal of the control signal converter, a source of the fourth MOS transistor gets grounded, and a drain of the fourth MOS transistor connects to the negative electrode of the second LED lamps string.

A method for simultaneously adjusting brightness and color temperature, wherein comprising following steps:

A, the phase control dimmer cuts the phase of the input alternating current and changes the effective voltage of the alternating current;

B, the rectification module rectifies the AC after being cut and outputs to the LED module, to adjust the brightness of the LED module;

C, the phase detection module detects the phase information after being cut, and outputs the current control signal according to the phase information after being cut;

D, the current control module controls a change of the mixed color brightness proportion of the LED module, according to the current control signal, to adjust the color temperature of the LED module.

An LED lamp, wherein comprising the apparatus for simultaneously adjusting the brightness and the color temperature as described above.

Comparing to the prior art, the present invention provides an apparatus and method for simultaneously adjusting the brightness and the color temperature and the LED lamp, wherein the apparatus for simultaneously adjusting the brightness and the color temperature comprises a phase control dimmer, a rectification module, a phase detection module, a current control module and a LED module. Changing an effective voltage of an alternating current by the phase control dimmer cutting a phase of an input alternating current, and rectifying the alternating current after being cut before outputting to the LED module by the rectification module, to adjust a brightness of the LED module; detecting a phase information after being cut through the phase detection module, and outputting a current control signal to the current control module according to the phase information after being cut, the current control module controls a change of a mixed color brightness proportion of the LED module according to the current control signal, to adjust a color temperature of the LED module; changing the brightness of the LED module by the phase control dimmer cutting the phase of the input alternating current, while outputting the current control signal to control the mixed color brightness proportion of the LED module according to the phase cutting information, to achieve a simultaneous adjustment of the color temperature, having a control circuit simple and a range of adjusting the color temperature wide, achieving a simultaneously adjustment for the brightness and the color temperature without increasing any additional power consumptions.

DETAILED DESCRIPTION OF EMBODIMENTS

According to a plurality of defects in the prior art, that it is impossible to achieve a simultaneous adjustment for the brightness and the color temperature in a convenient and fast way, with a low power consumption, the purpose of the present invention is providing an apparatus and a method for simultaneously adjusting the brightness and the color temperature, and a led lamp, which changes the brightness of an LED module by a phase controlled dimmer cutting a phase of an input AC, while at a same time, outputting a current control signal according to a phase cutting information before controlling a mixed brightness ratio of the LED module and achieving a synchronous adjustment for the color temperature, having a control circuit simple and a range wide of adjusting the color temperature, achieving a synchronous adjustment of the brightness and the color temperature without increasing an additional power consumption.

In order to make the purpose, technical solution and the advantages of the present invention clearer and more explicit, further detailed descriptions of the present invention are stated herein, referencing to the attached drawings and some preferred embodiments of the present invention. It should be understood that the detailed embodiments of the invention described here are used to explain the present invention only, instead of limiting the present invention.

Referencing toFIG. 1, the apparatus for simultaneously adjusting the brightness and the color temperature comprises a phase control dimmer10, a rectification module20, a phase detection module30, a current control module40and an LED module50, an input terminal of the phase control dimmer10connects to an alternative current (AC) supplied, an output terminal of the phase control dimmer10connects to an input terminal of the rectification module20, an output terminal of the rectification module20connects to an input terminal of the phase detection module30and the LED module50, an output terminal of the phase detection module30further connects to the LED module50through the current control module40.

Further referencing toFIG. 2, the present disclosure uses the phase control dimmer10to cut a phase of the input AC, and changes an effective voltage of the AC (shown as (a) (b) inFIG. 2, line voltage stands for the input voltage of the phase control dimmer), and the rectification module20makes a rectification process to the AC after being cut (as the (c) inFIG. 2) and outputs to the LED module50, before driving an on-off state of the LED module50(as the (d) inFIG. 2), in the present embodiment, the rectification module20adopts a bridge rectifier, when a current of the LED module50is constant, by the phase control dimmer10cuts a phase of a sine wave, and changes an effective voltage of the LED module50, it is possible to adjust a brightness of the LED module50directly, having a current structure simple, and achieving a brightness adjustment without requiring a power converter.

Also, the present disclosure further detects a phase information after being cut by the phase detection module30, and outputs a current control signal to the current control module40according to a phase information after being cut, the current control module40controls a change of a mixed color brightness proportion of the LED module50according to the current control signal, to adjust the color temperature of the LED module50. Thus a simultaneous adjustment of both the brightness and the color temperature can be achieved through a phase control dimmer10.

In a real implementation, the current control module40comprises a first current control unit401and a second current control unit402; the LED module50comprises a first LED lamps string501and a second LED lamps string502, such as adopting a cold light LED lamps string and a warm light LED lamps string respectively, a first output terminal of the phase detection module30connects to the first LED lamps string501through the first current control unit401, a second output terminal of the phase detection module30connects to the second LED lamps string502through the second current control unit402, Comparing with a technique in the prior art that shunting one light string therein through a bypass circuit, wherein the bypass circuit will generate an additional power consumption, which may reach 50% in a worst case (only one light string is lit), while in the present disclosure, it is adopting a current source connected in serial with the LED lamps string to control the brightness, even only one lamp string is lit on, there is still no additional power consumption generated, thus realizing the brightness adjustment while achieving a purpose of saving energy as much as possible.

Further, referencing toFIG. 3, the phase detection module30comprises a voltage sampling unit301, a comparison unit302, a timer303, an arithmetic logic unit304and a control signal converter305, an input terminal of the voltage sampling unit301connects to an output terminal of the rectification module20, an output terminal of the voltage sampling unit301connects to an input end of the comparison unit302, an output terminal of the comparison unit302connects to an input terminal of the control signal converter305through the timer303and the arithmetic logic unit304, an output terminal of the control signal converter305connects to the current control module40.

Sampling an output voltage of the rectification module20by the voltage sampling unit301and setting a voltage detection threshold, before the comparison unit302comparing the output voltage of the rectification module20to the voltage detection threshold, and outputting a level signal correspondingly according to a comparison result. The timer303starts counting according to the level signal before outputting a timing value to the arithmetic logic unit304, followed by calculating a current value of the LED module50by the arithmetic logic unit304according to the timing value; and converting the current value into the current control signal correspondingly by the control signal converter305, to control the change of the mixed color brightness proportion of the LED module50, so as to realizing an adjustment for the color temperature of the LED module50.

Specifically, a first output terminal of the current control module40connects to the first current control unit401, and a second output terminal of the current control module40connects to the second current control unit402. During a logic operation, the arithmetic logic unit304calculates respectively the current of the first LED light string501and the current of the second LED light string502, according to the timing value, before being converted respectively into a first current control signal and a second current control signal by the control signal converter305, and notifies the current control module40to change the current of the LED lamps string, the first current control unit401and the second current control unit402controls respectively the current in the first LED lamps string501and the current in the second LED lamps string502according to the first current control signal and the second current control signal, thus controlling the mixed color brightness proportion of the first LED lamps string501and the second LED light string502according to any requirements, so as to achieve an effect of adjusting the color temperature.

Preferably, the voltage sampling unit301comprises a first resistor R1, a second resistor R2and a first power source U1, one end of the first resistor R1connects to an input terminal of the rectification module20, another end of the first resistor R1connects to one end of the second resistor R2and the comparison unit302; another end of the second resistor R2connects to a negative electrode of the first power source U1and ground; a positive electrode of the first power source U1connects to the comparison unit302; a voltage output from the first power source U1is the voltage detection threshold; the comparison unit302comprises a comparator A1, a non-inverting input terminal of the comparator A1connects to another end of the first resistor R1, an inverting input terminal of the comparator A1connects to the positive electrode of the first power source U1, and an output terminal of the comparator A1connects to an Input terminal of the timer303.

Referencing toFIG. 4together, when the phase detection module30is working, sampling an output voltage VAC of the rectification module20by configuring the first resistor R1and the second resistor R2, before outputting to the non-inverting input terminal of the comparator A1, while a voltage detection threshold Vth is output to the inverting input terminal of the comparator A1, and the comparator A1compares the output voltage VAC of the rectification module20to the voltage detection threshold Vth, when the output voltage of the rectification module20is less than the voltage detection threshold, that is, VAC<Vth, the comparator A1outputs a first level V1; when the output voltage of the rectification module20is greater than the voltage detection threshold, that is, VAC>Vth, the comparator A1outputs a second level V2; in some embodiments, the comparator A1compares the VAC*R2/(R1+R2) to the voltage detection threshold Vth, when the VAC*R2/(R1+R2) is less than the voltage detection threshold, that is, VAC*R2/(R1+R2)<Vth, the comparator A1outputs a first level V1; when the VAC*R2/(R1+R2) is greater than the voltage detection threshold, that is, VAC*R2/(R1+R2)>Vth, the comparator A1outputs a second level V2; when an output level of the comparator A1changes from the second level V2to the first level V1, the timer303is cleared before starting to count; and when the output level of the comparator A1changes from the first level V1to the second level V2, the timer303stops counting and outputs the timing value, and the timing value is Tcalc at the time, the arithmetic logic unit304calculates respectively each current of both LED lamps strings Iled1, Iled2, by a preset algorithm according to the Tcalc, before generating respectively a first current control signal and a second current control signal by the control signal converter305, and outputting to the first current control unit401and the second current control unit402to control respectively the currents in both LED lamps strings, and realizing a color temperature adjustment by matching a brightness of both lamps strings having two color temperatures. Due to the lamps strings having different brightness and color temperatures can be controlled independently, thus all color temperatures between the color temperature1and the color temperature2may be achieved. Comparing to the prior art of CN201410240336.5, wherein a lamps string has current flowing through all the time, making a maximum adjustment range of the color temperature be between the color temperature1and (color temperature1+color temperature2)/2. Thus the color temperature in the present disclosure has a wide adjustment range, and a more applicable occasion.

In a real implementation, the preset algorithm of the arithmetic logic unit304may be designed different according to a different requirement, for example, when a first algorithm is designed to achieve a continuous change of the color temperature following the brightness, then the preset algorithm is: Iled1=Iint*Tcut/T; Iled2=Iint*(T−Tcut)/T. wherein lint is a sum of the currents of both lamps strings when the input power source has no cutting, T is a period after an AC rectification, Tcut=Tcalc−Toffset; Toffset may be calculated by a trigonometric formula with the Vth and a Vmax.

A second algorithm is designed to keep a color temperature in a specific brightness range, then the preset algorithm is: if Tcalc<t1, then Iled1=I11, Iled2=I21, if t1<Tcalc<t2, then Iled1=I12, Iled2=I22; if t2<Tcalc<t3, then Iled1=I13, Iled2=I23; . . . , and so on.

A third is designed to keep the brightness unchanged, and the color temperature changing only, then the preset algorithm is: making a sum of the currents of both lamps strings Icut increase according to a decrease of the effective voltage, before adjusting a proportional relationship between the Iled1and the Iled2as needed. A formula of the Icut is as below:

0≤Tcut<T, and let Iled1=Icut*Tcut/T; Iled2=Icut*(T−Tcut)/T, then it is possible to achieve adjusting the color temperature only, without adjusting the brightness. Of course, three algorithms listed above are for examples only, and a user may design other algorithms according to an actual requirement, which is not limited in the present disclosure.

Further, the control signal converter305converts into a control signal for the current control module40, according to the current values of the Iled1and Iled2calculated. In a real implementation, the control signal converter305may be a D/A (digital-to-analog) convertor, converting into a signal of an analog voltage or a signal of an analog current to control a current controller according to a calculated value of the Iled1and the Iled2, or may be a PWM (pulse-width-modulation) convertor, converting into a PWM signal to control the current controller according to the calculated values of the Iled1and the Iled2.

Accordingly, the current control module40in the present disclosure provides two embodiments, shown asFIG. 5, in a first embodiment, the first current control unit401comprises a first operational amplifier Q1, a first MOS transistor M1, and a third resistor R3; the second current control unit402comprises a second operational amplifier Q2, a second MOS transistor M2, and a fourth resistor R4; a first input terminal of the first operational amplifier Q1connects to a first output terminal of the control signal converter305, a second input terminal of the first operational amplifier Q1connects to a source of the first MOS transistor M1, and gets grounded through a third resistor R3; an output terminal of the first operational amplifier Q1connects to a gate of the first MOS transistor M1; a drain of the first MOS transistor M1connects to a negative electrode of the first LED lamps string501;

a first input terminal of the second operational amplifier Q2connects to a second output terminal of the control signal converter305, a second input terminal of the second operational amplifier Q2connects to a source of the second MOS transistor M2and gets grounded through the fourth resistor R4, an output terminal of the second operational amplifier Q2connects to a gate of the second MOS transistor M2; a drain of the second MOS transistor M2connects to a negative electrode of the second LED string502. That is, the control signal converter305herein is a D/A converter, converting the current value into the signal of the analog voltage before outputting to the first current control unit401and the second current control unit402, then the first operational amplifier Q1and the second operational amplifier Q2control the currents of the first MOS transistor M1and the second MOS transistor M2according to the analog voltage input and the reference voltage input, so as to achieve a control to the current in the LED lamps string.

Shown asFIG. 6, in a second embodiment, the first current control unit401comprises a third MOS transistor M3; the second current control unit402comprises a fourth MOS transistor M4; a gate of the third MOS transistor M3connects to a first output terminal of the control signal converter305, and a source of the third MOS transistor M3gets grounded, a drain of the third MOS transistor M3connects to the negative electrode of the first LED lamps string501; a gate of the fourth MOS transistor M4connects to a second output terminal of the control signal converter305, and a source of the fourth MOS transistor M4gets grounded, and a drain of the fourth MOS transistor M4connects to the negative electrode of the second LED lamps string502. That is, the control signal converter305herein is a PWM converter, converting the current value into a PWM signal before outputting to the current control module40, controlling a switch of the third MOS transistor M3and the fourth MOS transistor M4by a duty cycle of the PWM signal, so as to control an average current in LED lamps strings.

The present disclosure further provides a method for simultaneously adjusting brightness and color temperature, shown asFIG. 7, the method for simultaneously adjusting brightness and color temperature comprises following steps:

S100, the phase control dimmer cuts the phase of the input alternating current and changes the effective voltage of the alternating current;

S200, the rectification module rectifies the AC after being cut and outputs to the LED module, to adjust the brightness of the LED module;

S300, the phase detection module detects the phase information after being cut, and outputs the current control signal according to the phase information after being cut;

S400, the current control module controls a change of the mixed color brightness proportion of the LED module, according to the current control signal, to adjust the color temperature of the LED module.

Details may reference to the embodiments of the apparatus above.

The present disclosure further provides an LED lamp, being able to simultaneously adjusting the brightness and the color temperature, wherein comprising the apparatus for simultaneously adjusting the brightness and the color temperature as described above. Since the apparatus for simultaneously adjusting the brightness and the color temperature has been described in details above, no more details will be described herein.

All above, the present disclosure provides an apparatus and method for simultaneously adjusting the brightness and the color temperature and the LED lamp, wherein the apparatus for simultaneously adjusting the brightness and the color temperature comprises a phase control dimmer, a rectification module, a phase detection module, a current control module and a LED module. Changing an effective voltage of an alternating current by the phase control dimmer cutting a phase of an input alternating current, and rectifying the alternating current after being cut before outputting to the LED module by the rectification module, to adjust a brightness of the LED module; detecting a phase information after being cut through the phase detection module, and outputting a current control signal to the current control module according to the phase information after being cut, the current control module controls a change of a mixed color brightness proportion of the LED module according to the current control signal, to adjust a color temperature of the LED module; changing the brightness of the LED module by the phase control dimmer cutting the phase of the input alternating current, while outputting the current control signal to control the mixed color brightness proportion of the LED module according to the phase cutting information, to achieve a simultaneous adjustment of the color temperature, having a control circuit simple and a range of adjusting the color temperature wide, achieving a simultaneously adjustment for the brightness and the color temperature without increasing any additional power consumptions.

It should be understood that, the application of the present invention is not limited to the above examples listed. Ordinary technical personnel in this field can improve or change the applications according to the above descriptions, all of these improvements and transforms should belong to the scope of protection in the appended claims of the present invention.