CN204887557U - A digital dimming system for LED lamp - Google Patents
A digital dimming system for LED lamp Download PDFInfo
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- CN204887557U CN204887557U CN201520509607.2U CN201520509607U CN204887557U CN 204887557 U CN204887557 U CN 204887557U CN 201520509607 U CN201520509607 U CN 201520509607U CN 204887557 U CN204887557 U CN 204887557U
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Abstract
An embodiment of the utility model provides a digital dimming system for LED lamp, number of pass word light modulator will adjust luminance the message modulation and generate the modulated signal on the sine wave signal of alternating current power supply output, and digifax the control unit carries out the demodulation to the modulated signal after filtering, rectification and obtains the information of adjusting luminance, obtain the control information who corresponds with the information of adjusting luminance according to the control strategy who prestores, adjust luminance according to the LED lamp of control information in to the LED luminescence unit. Having realized using digital light modulator to come to adjust luminance to the LED lamp, basically not changed grid voltage's wave form, to the interference of electric wire netting is little, the noise is little, the degree of depth of just adjusting luminance and linearity effect are better.
Description
Technical Field
The utility model relates to a LED lighting technology field especially relates to a digital dimming system for LED lamp.
Background
An LED (light emitting diode) is a solid semiconductor device capable of converting electric energy into visible light, and directly converts electricity into light. The LED lamp has the advantages of energy conservation, environmental protection, light control, strong practicability, high stability, short response time, long service life and the like, and is widely applied to various illumination fields today advocating low-carbon life.
The dimmer that LED lamp that can adjust luminance at present adopted adopts the mode of phase cut mostly, and this kind of mode of adjusting luminance is disturbed the electric wire netting greatly, and the noise is big to because the electric current harmonic in the electric wire netting is big, power factor is low, and LED drive is relatively poor to the compatibility of phase cut electric wire netting signal, is adjusting luminance the in-process to the LED lamp, and the LED lamp is glimmering easily, and the degree of depth and the linearity of adjusting luminance are also not ideal.
SUMMERY OF THE UTILITY MODEL
The utility model provides a digital dimming system for LED lamp to solve the cut looks simulation dimming system among the prior art and disturb big to the electric wire netting, the LED drive is relatively poor to the compatibility of cut looks electric wire netting signal, in-process of adjusting luminance to the LED lamp, the LED lamp flickers easily, the unsatisfactory technical defect of degree of depth and linearity of adjusting luminance.
According to the utility model discloses a first aspect provides a digital dimming system for LED lamp, include: the LED light source comprises a digital light modulator, a filtering unit, a rectifying unit, a digital-analog control unit and an LED light-emitting unit, wherein the digital light modulator is connected with an alternating current power supply, the filtering unit is respectively connected with the digital light modulator and the rectifying unit, and the digital-analog control unit is respectively connected with the rectifying unit and the LED light-emitting unit; wherein,
the digital dimmer is used for modulating dimming information on a sine wave signal output by the alternating current power supply to generate a modulated signal;
the filtering unit is used for filtering the modulated signal;
the rectification unit is used for rectifying the filtered modulated signal;
the digital-analog control unit is used for demodulating the rectified modulated signal to obtain the dimming information, obtaining control information corresponding to the dimming information according to a pre-stored control strategy, and dimming the LED lamp in the LED light-emitting unit according to the control information.
The system as described above, the digital dimmer, is specifically configured to:
and phase cutting is carried out on each half cycle of the sine wave signal, if the dimming information is 0, the cut phase belongs to a preset first interval, and if the dimming information is 1, the cut phase belongs to a preset second interval, wherein the second interval is larger than the first interval.
The system as described above, the digital dimmer, is specifically configured to:
if the dimming information is 0, no level signal is added to the zero crossing point of the sine wave signal, and if the dimming information is 1, the level signal is added to the zero crossing point of the sine wave signal.
The system as described above, the digital dimmer, is specifically configured to:
dimming information is converted into Manchester code and added to the sine wave signal.
As the system described above, the digital-to-analog control unit includes:
a demodulation processing chip, a PWM chip and a main circuit, wherein the demodulation processing chip is respectively connected with the rectification unit and the PWM chip, the main circuit is respectively connected with the PWM chip and the LED light-emitting unit,
the demodulation processing chip is used for demodulating the rectified modulated signal to obtain the dimming information, obtaining control information corresponding to the dimming information according to a prestored control strategy, and adjusting the PWM signal output by the PWM chip according to the control information;
the main circuit is used for adjusting the input current of the LED light-emitting unit according to the PWM signal and dimming the LED lamp.
The system as described above is such that,
the demodulation processing chip is specifically used for increasing the duty ratio of the PWM signal according to the control information;
the main circuit is specifically configured to increase the input current of the LED lighting unit according to the duty ratio of the PWM signal, and turn on the LED lamp.
The system as described above is such that,
the demodulation processing chip is specifically used for reducing the duty ratio of the PWM signal according to the control information;
the main circuit is specifically configured to reduce the input current of the LED lighting unit according to the duty cycle reduction of the PWM signal, and dim the LED lamp.
The system as described above is such that,
the demodulation processing chip is specifically used for increasing the frequency of the PWM signal according to the control information;
the main circuit is specifically configured to increase the input current of the LED lighting unit according to the frequency increase of the PWM signal, and turn on the LED lamp.
The system as described above is such that,
the demodulation processing chip is specifically used for reducing the frequency of the PWM signal according to the control information;
the main circuit is specifically configured to reduce the input current of the LED lighting unit according to the decrease in the frequency of the PWM signal, and dim the LED lamp.
The embodiment of the utility model provides a digital dimming system for LED lamp generates modulated signal through digital light modulator with the information modulation of adjusting luminance on alternating current power supply output's sine wave signal, and digital analog control unit demodulates the modulated signal after filtering, rectification and acquires the information of adjusting luminance, acquires the control information that corresponds with the information of adjusting luminance according to the control strategy that prestores, adjusts luminance according to the LED lamp of control information in to the LED luminescence unit. The LED lamp dimming device has the advantages that the digital dimmer is used for dimming the LED lamp, the waveform of the voltage of a power grid is basically not changed, the interference to the power grid is small, the noise is low, and the dimming depth and the linearity effect are good.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic structural diagram of a digital dimming system for an LED lamp according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a modulation method of a digital light modulator according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a modulation scheme of another digital dimmer according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a modulation method of another digital dimmer according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another digital dimming system for an LED lamp according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Fig. 1 is a schematic structural diagram of a digital dimming system for an LED lamp according to an embodiment of the present invention, as shown in fig. 1, the system includes: a digital light modulator 1, a filtering unit 2, a rectifying unit 3, a digital-to-analog control unit 4 and an LED light-emitting unit 5,
the digital light modulator 1 is connected with an alternating current power supply 6, the filtering unit 2 is respectively connected with the digital light modulator 1 and the rectifying unit 3, and the digital-analog control unit 4 is respectively connected with the rectifying unit 3 and the LED light-emitting unit 5; wherein,
a digital dimmer 1 for modulating dimming information on a sine wave signal output from an ac power supply 6 to generate a modulated signal;
the filtering unit 2 is used for carrying out filtering processing on the modulated signals;
the rectifying unit 3 is used for rectifying the filtered modulated signal;
and the digital-analog control unit 4 is used for demodulating the rectified modulated signal to obtain dimming information, obtaining control information corresponding to the dimming information according to a pre-stored control strategy, and dimming the LED lamp in the LED light-emitting unit according to the control information.
Specifically, the digital dimmer 1 receives a sine wave signal from the ac power supply 6, modulates dimming information acquired in advance on the sine wave signal, and generates a modulated signal. The dimming information may be pre-stored in the digital dimmer 1, or the digital dimmer 1 may obtain the dimming information from the control center in real time. It should be noted that, the specific content of the dimming information is represented according to a well-agreed dimming specification in advance, and the dimming specification specifically includes: the number of bits of each group of digits can be set according to actual needs, for example: 5 bits, 8 bits or 16 bits.
The digital dimmer 1 can select a suitable modulation mode to modulate dimming information on the sine wave signal according to the actual application requirement to generate a modulated signal. The number of bits to modulate on each sine wave signal is set according to the selected modulation scheme. When the number of bits that can be modulated per sine wave signal is M, M is equal to or greater than 1, and when the number of bits of the dimming information is N in total, the number of sine wave signals that need to be modulated is [ N/M ]. For example, the following steps are carried out: a group of dimming information is preset to be a 16-bit digital signal, and a 2-bit digital signal is preset to be modulated on a sine wave signal sent in each power grid period, so that 8 sine wave signals sent in 8 power grid periods are required to be modulated respectively in total to complete one-time digital dimming.
The digital light modulator 1 sends the generated modulated signal to the filtering unit 2, the filtering unit 2 performs filtering processing on the modulated signal and sends the filtered signal to the rectifying unit 3, and the rectifying unit 3 performs rectifying processing on the filtered modulated signal and sends the rectified signal to the digital-to-analog control unit 4.
The digital-analog control unit 4 stores preset control strategies in advance, and the control strategies include: and correspondence between dimming information and control information. The information represented by the specific digital signal in the dimming information is pre-negotiated, for example: dimming information "1001" indicates that the LED lamp in the LED lighting unit 5 is turned on; dimming information "0110" indicates that the LED lamp in the LED lighting unit 5 is dimmed. The digital-analog control unit 4 demodulates the received modulated signal to obtain dimming information, queries a preset control strategy according to the obtained dimming information to obtain corresponding control information, and performs dimming on the LED lamp in the LED light-emitting unit 5.
The digital-analog control unit 4 stores preset control strategies in advance, and the control strategies include: and correspondence between dimming information and control information.
Specifically, when the digital-analog control unit 4 receives dimming information for turning on the LED lamp, the input current of the LED light-emitting unit 5 is controlled to be increased according to the acquired control information, so as to turn on the LED lamp; when dimming information for dimming the LED lamp is received, the input current of the LED lighting unit 5 is controlled to be reduced according to the acquired control information, thereby dimming the LED lamp.
The digital-to-analog control unit 4 increases or decreases the input current of the LED lighting unit 5 according to the dimming information in many ways, which can be selected according to the actual application requirement, and this embodiment does not limit this. Such as: the input current of the LED lighting unit 5 is regulated by a pulse width modulation method, the input current of the LED lighting unit 5 is regulated by a transformer method, and the like. Furthermore, for the same regulation and control mode, different device parameters may be regulated and controlled to regulate and control the input current of the LED lighting unit 5, for example, when the input current of the LED lighting unit 5 is regulated and controlled in a PWM mode, the input current of the LED lighting unit 5 may be regulated and controlled by controlling the frequency of the PWM signal, or the input current of the LED lighting unit 5 may be regulated and controlled by controlling the amplitude of the PWM signal. Therefore, in the control strategy, the control information corresponding to the dimming information includes, for the plurality of control methods: control modes and control parameters, for example: the control mode is as follows: the PWM control mode comprises the following control parameters: the frequency of the PWM signal.
It is noted that when the digital dimmer 1 modulates dimming information onto a plurality of sine wave signals, such as: a group of dimming information is 8-bit digital signals, and is modulated on 2 sine wave signals to be sent, control information preset in a control strategy in the digital-to-analog control unit 4 comprises control information corresponding to 4-bit dimming digital signals of each sine wave signal, and the digital-to-analog control unit 4 needs to regulate and control input current of the LED light-emitting unit 5 twice according to the control information corresponding to the dimming information on the two sine wave signals to complete dimming.
In the digital dimming system for the LED lamp provided in this embodiment, the digital dimmer modulates dimming information on a sine wave signal output by the ac power supply to generate a modulated signal, the digital-to-analog control unit demodulates the filtered and rectified modulated signal to obtain dimming information, obtains control information corresponding to the dimming information according to a pre-stored control strategy, and dims the LED lamp in the LED light emitting unit according to the control information. The LED lamp dimming device has the advantages that the digital dimmer is used for dimming the LED lamp, the waveform of the voltage of a power grid is basically not changed, the interference to the power grid is small, the noise is low, and the dimming depth and the linearity effect are good.
For the digital dimmer 1 in the embodiment shown in fig. 1, the dimming information may be modulated on the sine wave signal by selecting a suitable modulation method according to the actual application requirement to generate the modulated signal. For a more clear explanation of the modulation process, the modulation scheme of fig. 2-4 is illustrated as follows:
fig. 2 is a schematic diagram of a modulation method of a digital dimmer according to an embodiment of the present invention, in which the digital dimmer in this example modulates dimming information on a sine wave signal by applying a phase-cut modulation method to generate a modulated signal, see fig. 2, which is specifically described as follows:
the digital dimmer 1 phase-cuts each half cycle of a sine wave signal from an ac power supply 6 to transmit digital dimming information, and if the dimming information is 0, the phase cut out belongs to a preset first interval, and if the dimming information is 1, the phase cut out belongs to a preset second interval, where the second interval is greater than the first interval. It should be noted that the values of the preset cutting phases in the first interval and the second interval are small, so that the interference to the power grid is small. Referring to fig. 2, for example:
if the dimming information is 0, the first interval is 0 to 3 degrees, i.e. the cut-off phase is represented by 0 to 3 degrees; if the dimming information is 1, the second interval is 3 to 6 degrees, i.e., the phase cut is represented by 3 to 6 degrees. As can be seen from this, when the dimming information "1001" is to be modulated into the sine wave signal, as shown in fig. 2, the phase to be cut off is 3 when the digital signal to be modulated is "1" at the time of the 0.5 th cycle, the phase to be cut off is 0 when the digital signal to be modulated is "0" at the time of the 1 st cycle, the phase to be cut off is 0 when the digital signal to be modulated is "0" at the time of the 1.5 th cycle, and the phase to be cut off is 6 when the digital signal to be modulated is "1" at the time of the 2 nd cycle. Thereby modulating dimming information "1001" into the sine wave signal.
It should be noted that, in the embodiment shown in fig. 2, a 2-bit digital signal is modulated on a sine wave signal transmitted in each grid cycle as an example, and therefore, the dimming information "1001" needs to modulate 2 sine wave signals transmitted in 2 grid cycles respectively in total to complete one digital dimming.
Fig. 3 is a schematic diagram of another modulation method of the digital dimmer according to an embodiment of the present invention, in which the digital dimmer in this example modulates dimming information on a sine wave signal by applying a level modulation method to generate a modulated signal, see fig. 3, which is specifically described as follows:
the digital dimmer 1 adds a level signal to a zero-crossing point of a sine wave signal from an alternating-current power supply 6 to transmit digital dimming information, does not add the level signal to the zero-crossing point of the sine wave signal if the dimming information is 0, and adds the level signal to the zero-crossing point of the sine wave signal if the dimming information is 1. Or, if the dimming information is 1, adding no level signal to the zero crossing point of the sine wave signal, and if the dimming information is 0, adding a level signal to the zero crossing point of the sine wave signal. Because the harmonic wave influence generated by the level signal is small, the interference to the power grid is small. Referring to fig. 3, for example:
if the dimming information is 0, no level signal is added to the zero crossing point of the sine wave signal, and if the dimming information is 1, the level signal is added to the zero crossing point of the sine wave signal. As can be seen from this, when the dimming information "1001" is to be modulated into the sinusoidal signal, as shown in fig. 3, the digital signal to be modulated is "1" at the zero-crossing point of the 0.5 th cycle, the level signal is added, and when the digital signal to be modulated is "0" at the zero-crossing point of the 1 st cycle, the level signal is not added, and when the digital signal to be modulated is "0" at the zero-crossing point of the 1.5 th cycle, the level signal is not added, and when the digital signal to be modulated is "1" at the zero-crossing point of the 2 nd cycle, the level signal is added. Thereby modulating dimming information "1001" into the sine wave signal.
It should be noted that, in the embodiment shown in fig. 3, a 2-bit digital signal is modulated on a sine wave signal transmitted in each grid cycle as an example, and therefore, the dimming information "1001" needs to modulate 2 sine wave signals transmitted in 2 grid cycles respectively in total to complete one digital dimming.
Fig. 4 is a schematic diagram of a modulation method of another digital dimmer according to an embodiment of the present invention, in which the digital dimmer in this example modulates dimming information on a sine wave signal by applying a coded modulation method to generate a modulated signal, see fig. 4, which is specifically described as follows:
the digital dimmer 1 modulates a set of coded signals before the zero crossing point of the sine wave signal from the ac power supply 6 to deliver digital dimming information, and the content of the dimming information modulated by the zero crossing point of each half cycle in the sine wave signal generated for one grid cycle depends on the coding mode applied. Because the harmonic wave influence generated by the coded signal is small, the interference to the power grid is small. Referring to fig. 4, manchester code is illustrated as follows:
since the manchester code of zero-crossing modulation every half cycle represents 2-bit digital dimming information, if the dimming information "0110" is to be modulated into the sine wave signal, as shown in fig. 4, the manchester code signal is added when the digital signal to be modulated is "01" at the zero-crossing time of the 0.5 th cycle, and the manchester code signal is added when the digital signal to be modulated is "10" at the zero-crossing time of the 1 st cycle.
It should be noted that, in the embodiment shown in fig. 4, a 4-bit digital signal is modulated on the sine wave signal transmitted in each grid cycle as an example, and therefore, the dimming information "0110" needs to modulate 1 sine wave signal transmitted in 1 grid cycle in total, that is, one time of digital dimming is completed.
Fig. 5 is a schematic structural diagram of another digital dimming system for LED lamps provided in the embodiment of the present invention, and this embodiment provides a mode of regulating and controlling LED lamps by using control PWM signals. As shown in fig. 5, based on the embodiment shown in fig. 1, the digital-analog control unit 4 includes: a demodulation processing chip 41, a PWM chip 42, and a main circuit 43, where it should be noted that the specific circuit form of the main circuit 43 can be set according to the actual application requirement, the main circuit 43 shown in fig. 5 is only a preferred embodiment, and the main circuit 43 shown in fig. 5 specifically includes: a switch tube Q1, a transformer T1, and other components such as capacitors and resistors.
The demodulation processing chip 41 is connected to the rectifying unit 3 and the PWM chip 42, respectively, and the main circuit 43 is connected to the PWM chip 42 and the LED lighting unit 5, respectively, wherein,
the demodulation processing chip 41 is configured to demodulate the rectified modulated signal to obtain dimming information, obtain control information corresponding to the dimming information according to a pre-stored control strategy, and adjust the PWM signal output by the PWM chip 42 according to the control information;
the main circuit 43 is configured to adjust an input current of the LED lighting unit 5 according to the PWM signal, so as to adjust the light of the LED lamp.
Specifically, the control information corresponding to the dimming information in the control strategy includes: a control mode and control parameters, where the control mode in this embodiment is a PWM control mode, and the control parameters are: the frequency of the PWM signal or the duty ratio of the PWM signal, different control parameters, correspond to different embodiments, and are specifically described as follows:
the control parameter one: the duty ratio of the PWM signal is specified by the control parameter:
the first condition is as follows: LED lamp capable of being turned on according to duty ratio of PWM signal
When the demodulation processing chip 41 demodulates the received modulated signal to obtain dimming information, if it is known that the dimming information indicates dimming information for turning on the LED lamp, the corresponding control information is to increase the duty ratio of the PWM signal;
the demodulation processing chip 41 increases the duty ratio of the PWM signal output from the PWM chip 42 in accordance with the control information, and the main circuit 43 controls the switching tube Q1 in accordance with the increase in the duty ratio of the PWM signal. When the duty ratio of the PWM signal is increased, the on-time of the switching transistor Q1 is increased, and the output power of the switching transistor Q1, that is, the average current is increased, so that the input current of the transformer T1 is increased, the output current of the transformer T1 is increased, and the input current of the LED lighting unit 5 is increased, thereby turning on the LED lamp.
Case two: duty ratio dimming LED lamp according to PWM signal
When the demodulation processing chip 41 demodulates the received modulated signal to obtain the dimming information, if it is known that the dimming information indicates dimming of the LED lamp, the corresponding control information is to reduce the duty ratio of the PWM signal;
the demodulation processing chip 41 reduces the duty ratio of the PWM signal output from the PWM chip 42 according to the control information, and the main circuit 43 controls the switching tube Q1 according to the reduction of the duty ratio of the PWM signal. Due to the fact that the duty ratio of the PWM signal is reduced, the on-time of the switching tube Q1 is reduced, the output power of the switching tube Q1 is reduced, that is, the average current is reduced, so that the input current of the transformer T1 is reduced, the output current of the transformer T1 is reduced, the input current of the LED lighting unit 5 is reduced, and the LED lamp is dimmed.
And a second control parameter: the control parameter is specifically described as the frequency of the PWM signal:
the first condition is as follows: frequency-modulated LED lamp according to PWM signal
When the demodulation processing chip 41 demodulates the received modulated signal to obtain dimming information, if it is known that the dimming information indicates dimming information for turning on the LED lamp, the corresponding control information is to increase the frequency of the PWM signal;
the demodulation processing chip 41 increases the frequency of the PWM signal output from the PWM chip 42 in accordance with the control information, and the main circuit 43 controls the switching tube Q1 in accordance with the increase in the frequency of the PWM signal. When the frequency of the PWM signal is increased, the on-time of the switching transistor Q1 is increased, and the output power of the switching transistor Q1, that is, the average current, is increased, so that the input current of the transformer T1 is increased, the output current of the transformer T1 is increased, and the input current of the LED lighting unit 5 is increased, thereby turning on the LED lamp.
Case two: frequency dimming LED lamp according to PWM signal
When the demodulation processing chip 41 demodulates the received modulated signal to obtain the dimming information, if it is known that the dimming information indicates dimming of the LED lamp, the corresponding control information is to reduce the frequency of the PWM signal;
the demodulation processing chip 41 reduces the frequency of the PWM signal output from the PWM chip 42 according to the control information, and the main circuit 43 controls the switching tube Q1 according to the reduction of the frequency of the PWM signal. Due to the reduction of the frequency of the PWM signal, the on-time of the switching tube Q1 is reduced, and the output power of the switching tube Q1, i.e. the average current, is reduced, so that the input current of the transformer T1 is reduced, the output current of the transformer T1 is reduced, and the input current of the LED lighting unit 5 is reduced, thereby dimming the LED lamp.
It should be noted that the control information may further include information about how much the LED lamp is turned on or turned off, which depends on how many sets of the same modulated signals are received by the demodulation processing chip 41. For each group of modulated signals, how much duty ratio to increase or how much to decrease may be preset according to an application scenario and parameters of the LED lamp, for example, if the demodulation processing chip 41 receives 2 groups of digital dimming signals for turning on the LED lamp, the amplitude of duty ratio adjustment when receiving 2 groups of digital dimming signals for turning on the LED lamp may be determined according to a function relationship of preset duty ratios corresponding to the multiple groups of digital dimming signals.
In the digital dimming system for the LED lamp provided in this embodiment, dimming information is modulated on a sine wave signal output by an ac power supply by a digital dimmer to generate a modulated signal, a digital-analog control unit demodulates the filtered and rectified modulated signal to obtain dimming information, obtains control information of a PWM signal corresponding to the dimming information according to a pre-stored control strategy, and adjusts the PWM signal according to the control information, so as to change an input current of an LED light emitting unit to dim the LED lamp. The LED lamp dimming device has the advantages that the digital dimmer is used for dimming the LED lamp, the waveform of the voltage of a power grid is basically not changed, the interference to the power grid is small, the noise is low, and the dimming depth and the linearity effect are good.
Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (9)
1. A digital dimming system for an LED lamp, comprising: the LED light source comprises a digital light modulator, a filtering unit, a rectifying unit, a digital-analog control unit and an LED light-emitting unit, wherein the digital light modulator is connected with an alternating current power supply, the filtering unit is respectively connected with the digital light modulator and the rectifying unit, and the digital-analog control unit is respectively connected with the rectifying unit and the LED light-emitting unit; wherein,
the digital dimmer is used for modulating dimming information on a sine wave signal output by the alternating current power supply to generate a modulated signal;
the filtering unit is used for filtering the modulated signal;
the rectification unit is used for rectifying the filtered modulated signal;
the digital-analog control unit is used for demodulating the rectified modulated signal to obtain the dimming information, obtaining control information corresponding to the dimming information according to a pre-stored control strategy, and dimming the LED lamp in the LED light-emitting unit according to the control information.
2. The system of claim 1, wherein the digital dimmer is specifically configured to:
and phase cutting is carried out on each half cycle of the sine wave signal, if the dimming information is 0, the cut phase belongs to a preset first interval, and if the dimming information is 1, the cut phase belongs to a preset second interval, wherein the second interval is larger than the first interval.
3. The system of claim 1, wherein the digital dimmer is specifically configured to:
if the dimming information is 0, no level signal is added to the zero crossing point of the sine wave signal, and if the dimming information is 1, the level signal is added to the zero crossing point of the sine wave signal.
4. The system of claim 1, wherein the digital dimmer is specifically configured to:
dimming information is converted into Manchester code and added to the sine wave signal.
5. The system of claim 1, wherein the digital-to-analog control unit comprises: a demodulation processing chip, a PWM chip and a main circuit, wherein the demodulation processing chip is respectively connected with the rectification unit and the PWM chip, the main circuit is respectively connected with the PWM chip and the LED light-emitting unit,
the demodulation processing chip is used for demodulating the rectified modulated signal to obtain the dimming information, obtaining control information corresponding to the dimming information according to a prestored control strategy, and adjusting the PWM signal output by the PWM chip according to the control information;
the main circuit is used for adjusting the input current of the LED light-emitting unit according to the PWM signal and dimming the LED lamp.
6. The system of claim 5,
the demodulation processing chip is specifically used for increasing the duty ratio of the PWM signal according to the control information;
the main circuit is specifically configured to increase the input current of the LED lighting unit according to the duty ratio of the PWM signal, and turn on the LED lamp.
7. The system of claim 5,
the demodulation processing chip is specifically used for reducing the duty ratio of the PWM signal according to the control information;
the main circuit is specifically configured to reduce the input current of the LED lighting unit according to the duty cycle reduction of the PWM signal, and dim the LED lamp.
8. The system of claim 5,
the demodulation processing chip is specifically used for increasing the frequency of the PWM signal according to the control information;
the main circuit is specifically configured to increase the input current of the LED lighting unit according to the frequency increase of the PWM signal, and turn on the LED lamp.
9. The system of claim 5,
the demodulation processing chip is specifically used for reducing the frequency of the PWM signal according to the control information;
the main circuit is specifically configured to reduce the input current of the LED lighting unit according to the decrease in the frequency of the PWM signal, and dim the LED lamp.
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| CN201520509607.2U CN204887557U (en) | 2015-07-14 | 2015-07-14 | A digital dimming system for LED lamp |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105101540A (en) * | 2015-07-14 | 2015-11-25 | 浙江生辉照明有限公司 | Digital dimming system for light-emitting diode (LED) lamp |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105101540A (en) * | 2015-07-14 | 2015-11-25 | 浙江生辉照明有限公司 | Digital dimming system for light-emitting diode (LED) lamp |
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