TW201220937A - Power conversion and control systems and methods for solid-state lighting - Google Patents

Abstract

A solid-state lighting system comprises a plurality of light-emitting devices (e.g., light-emitting diodes) and an alternating current to direct current (AC-DC) converter that converts AC power to DC power for powering the plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly, without the need for or use of a bridge rectifier or step-down transformer. According to one aspect of the invention, the light-emitting devices of the solid-state lighting system are autonomous and individually powered by a plurality of DC power supplies generated from the DC power produced by the AC-DC converter. According to another aspect, a plurality of phase-offset dimmer control signals are generated based on waveform distortions in a dimming signal produced by a conventional dimmer switch. The phase-offset dimmer control signals are used to individually control the dimming of the light-emitting devices.

Description

201220937 VI. OBJECTS OF THE INVENTION: FIELD OF THE INVENTION The present invention relates generally to power conversion and control methods and systems, and in particular to solid state lighting, such as, for example, hair & Method and system for power conversion and control of body (LED) lighting. t] Background of the Invention Due to the high efficiency and durability of light-emitting diodes (LEDs), they are ideal candidates for general illumination in residential, office and other environments. The efficiency of an incandescent lamp is only about 3%, while the efficiency of an LED is 30% or higher. The life of led is also 2 times longer than incandescent lamps and more than 5 times longer than energy-saving lamps. Although the lighting performance of LEDs is better than the conventional lighting technology, {曰 is the widespread adoption of LED lighting has slowed down. The main reason for the delay is the high price of the foam. In fact, the current cost of LED bulbs is about 10-25 times more expensive than white-light bulbs like light output. The high price of LED bulbs is significantly affected by the cost involved in manufacturing, particularly the cost involved in manufacturing power conversion circuits required to power LED bulbs. Incandescent bulbs receive power directly from the AC mains. However, LED bulbs are powered by DC. Therefore, if power from the AC mains will be used, an LED bulb must be equipped with a power conversion circuit to convert the AC mains power to DC. Figure 1 is a diagram of a prior art LED bulb 100 showing how AC power from an AC mains is converted to DC in an existing LED bulb. 201220937 First, a bridge rectifier (ie, a diode bridge) 1〇2 rectifies the AC input voltage from the AC mains to DC. The rectified voltage is then chopped by a smoothing circuit, the simplest form of which includes a smoothing capacitor 1〇4 that is coupled to the output of the bridge rectifier 102. Finally, the current-to-DC converter 106 steps down the rectified and filtered voltage to the appropriate DC output voltage Vout required to power the LEDs in the LED string 108. The DC output voltage Vout is set based on the number of LEDs in the LED string 108, which is determined during design by the desired light output level (i.e., lumens) of the LED bulb 100. In contrast, the LEDs of the LED string 108 are arranged in a series and surrounded by a diffuser lens. The diffuser lenses spread the light emitted by the LEDs. A conventional problem with the power conversion circuit of the LED bulb 100 is that the bridge rectifier 102 and the smoothing capacitor 1 〇4 cause a non-linear load to the AC mains. This non-linearity causes the input current from the AC mains to be extracted in the form of a series of narrow current pulses, as shown in Figure 2. These narrow current pulses have many _ harmonics and are characteristic of a power converter having a low power factor. The power factor is a factor of no difference between 〇 and 1, describing how efficiently a power converter transfers actual power from the AC power source to the load. - Low power factor is highly undesirable due to reduced conversion efficiency, heat generation in the AC mains generator and distribution system, and noise that may interfere with the performance of other devices. In order to avoid the problems associated with a low power factor, the actual AC-to-DC power converter typically utilizes a power factor correction (pFC) between the output of the bridge rectifier 1G2 and the input of the DC-to-DC converter 106. Regulator 302, as shown in Figure 3. The PFC pre-regulator 3〇2 acts to force the wheel-in current to be more sinusoidal and to phase with the AC input voltage to increase the power factor. Unfortunately, the introduction of the PFC pre-regulator 3〇2 reduces the efficiency in the moon, increases the number of parts and manufacturing costs, and makes it difficult to package the LED bulb 300 with a small form factor. In addition, the pFC pre-regulator 3〇2 typically includes a boost converter that generates an A-voltage. These high voltages tend to stress the parts of the LED bulbs, resulting in reliability problems. This high voltage also creates safety issues. Another problem with existing LED bulbs is related to their own inability to be controlled by conventional dimmer switches. Many homes and offices have dimmer switches designed to control the dimming of incandescent bulbs. It is desirable to be able to use these pre-installed dimmer switches to control the dimming of the LED bulbs. Figure 4 is a circuit diagram showing a conventional dimmer switch 4A. The dimmer switch 400 includes a variable resistor 402, a capacitor 404, a DIAC (AC diode) 406, and a TRIAC (AC triode) 408. TRIAC 408 is triggered when the voltage across capacitor 404 exceeds the breakdown voltage of DIAC 406. The voltage is increased and decreased depending on the cycle of the AC input voltage' and the triggering of TRIAC 408 is delayed by each positive and negative half cycle depending on the RC delay caused by variable resistor 402 and capacitor 404. Thus, the turn-on delay 512 results in a distortion dimming waveform having a lower average power, as shown in Figure 5B. In terms of angle, the conduction delay 512 is referred to in the industry as a "trigger angle" (180°-θ), where Θ is referred to as a "conducting angle." The firing angle can be controlled by adjusting the variable resistor 402 so that the average power output to the incandescent bulb 410 can be controlled, and thus the dimming of the incandescent bulb 410 can be controlled. 5 201220937 The TRIACs illuminator switch 400 is suitable for controlling the dimming of incandescent bulbs. Unfortunately, it does not provide an acceptable solution for existing LED bulbs, such as the prior art LED bulbs 100 and 300s of the light in Figures 1-3. The white weave bulb exhibits a resistive load during all parts of the AC input waveform period. However, LEDs are non-linear devices and are significantly less current drawn by incandescent bulbs. Especially when the dimming is increased (ie, the low light output level), the current drawn by the LED of the existing LED bulb may be too small, so that the current is reduced below the holding current of D1,111,0408. Under these conditions, the squat 1 匸 4 〇 8 can be re-triggered or cut off 'causing an annoying LED flash, or the LED bulb is prematurely turned off before reaching the desired dimming level. There is an AC-to-DC power conversion circuit between the AC power source and the LED that may also interfere with the ability of the TRIAc dimmer switch 400 to control the dimming of the LED. Considering the above-mentioned shortcomings and limitations of existing LED bulbs, it is desirable to obtain power conversion and control methods and devices for energy saving, low cost, compact, safe and reliable LED bulbs, and to provide use in a large dimming range. The dimmer switch controls the dimming capability of the LEDs of the LED bulb. SUMMARY OF THE INVENTION Summary of the Invention A solid state lighting system and a power conversion and control method are disclosed. An exemplary solid state lighting system includes a plurality of light emitting devices (eg, light emitting diodes) and an alternating current to direct current (AC-DC) converter that converts alternating current into direct current to power the A plurality of light-emitting devices. The AC-DC converter is configured to perform AC-DC conversion directly without or without

S 6 201220937 uses a bridge rectifier or step-down transformer. In accordance with one aspect of the invention, the illumination device of the solid state lighting system is self-regulating and is separately powered by a plurality of DC power sources that generate direct current that is free of the AC to DC converter. According to another aspect, the complex phase shift dimmer control signal is based on waveform distortion of a dimming signal produced by a conventional dimmer switch. The phase shift dimmer control signals are used to control dimming of the plurality of illumination devices. The solid state lighting system and method of the present invention provides a number of advantages over prior art solid state lighting systems and methods. First, the solid state lighting system of the present invention has a lower part count and is less expensive to manufacture than prior art solid state lighting systems. The use of the disclosed AC-to-DC converter eliminates the need for bridge rectifiers, step-down transformers, and power factor correction pre-regulator circuits, even if not all solid-state lighting system components are suitable for forming one or more integrated circuits (1C) ) wafer. The reduced number of parts and the ability to form solid state lighting system components in one or more 1C wafers reduces manufacturing costs and has the ability to achieve economies of scale. Second, the possibility of AC-to-DC converters, reduced parts counts, and the formation of some or all of the power conversion and control components in one or more 1C wafers has resulted in a solid-state lighting system that is more energy efficient than prior art solid state lighting systems. The possibility. Third, the solid state lighting system of the present invention is more reliable and has a longer life than prior art solid state lighting systems. The use of a separate power source to power the illuminating devices of the solid state lighting system of the present invention results in increased reliability, and the illuminating devices are configured to be self-disciplined and individually dimmable to allow the solid state lighting system of the present invention to last longer, which is Because if only one or a few illuminators fail, the entire system will not completely lose 201220937. Finally, the solid state lighting system of the present invention provides the very advantageous advantage of being dimmable in response to conventional dimmer switches, even to very low brightness, and without flicker or premature light cutoff. Other features and advantages of the present invention, including the above summary of the present invention and the description of the structure and operation of the exemplary embodiments, will now be described in detail with reference to the accompanying drawings Similar components. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a prior art LED bulb; FIG. 2 is an input line voltage W« applied to the prior art LED of FIG. 1 and an input line current extracted from the AC mains. Signal diagram; Figure 3 is a diagram of a prior art LED bulb equipped with a power factor correction (pFC) pre-regulator; Figure 4 is a conventional phase control (ie TRI ac (AC Triode)) modulation Circuit diagram of the optical switch; FIGS. 5A and 5B are line voltage Fk and dimming waveform associated with the TRIAC dimmer switch of FIG. 4; FIG. 6 is a diagram of a led bulb according to an embodiment of the present invention Figure 7 is a diagram of the LED bulb of Figure 6, showing how the LED of the LED bulb is enclosed in a transparent or translucent housing and how the electrical components of the LED bulb are coupled to a standard Edison threaded socket; Figure 8 is a circuit diagram of an AC-DC converter for implementing the AC-DC converter of the LED bulb of Figure 6; 201220937 Figure 9 is the eighth supply The AC input voltage of the AC-DC converter in the figure, and its input to the AC-DC converter A signal diagram of the relationship between the generated DC voltage Vdc and its inverse-Vdc; FIG. 10 is a diagram showing how the switching of the AC-DC converter in FIG. 8 depends on the instantaneous value of the AC input voltage and FIG. A table for switching and driving the comparison of the DC voltage Vdc and its inversion-Vdc generated by the output of the AC-DC converter; FIG. 11A is a diagram showing the positive half of the AC input waveform at F/«> Vdc During the week, how does the AC-DC converter in Figure 8 become and act as a circuit diagram of a buck converter; Figure 11B shows the negative half-cycle time of the AC input waveform at Fz > 2 < -Vdc How the AC-DC converter in Figure 8 is implemented as a circuit diagram of an inverting buck converter; Figure 12 is a charge that can be used to implement the voltage divider in the LED bulb of Figure 6. A circuit diagram of the pump divider; Figure 13A is a simplified equivalent circuit diagram of the charge pump voltage divider when the charge pump voltage divider of Figure 12 is configured to be in a "charged" state; Figure 13B is When the charge pump voltage divider of Figure 12 is configured to be in a "load" state, one of the charge pump voltage dividers Simplified equivalent circuit diagram; Fig. 14 is a diagram showing how the dimming of the LED of the LED bulb in Fig. 6 can be controlled by a conventional TRIAC dimmer switch; Fig. 15A-D is when Fig. 14 The signal diagram associated with the operation of the LED bulb in Figure 6 when the TRIAC dimmer switch is inactive; Figure 16A-D is when the TRIAC dimmer switch in Figure 14 is in effect 201220937 and 6 is a signal diagram associated with the operation of the LED bulb; Figure 17 is a comparison circuit comparing the dimmer waveform of the TRIAC dimmer switch of FIG. 14 with the DC voltage output by the AC-DC converter; Figure 18 is a circuit diagram of a frequency converter that can be used to convert duty cycle information in the logic signal S from the comparison circuit in Figure 17 to a higher frequency; Figures 19A and 19B are diagrams shown in Figure 18 How the DIM signal generated by the inverter has a high duty cycle of minimum dimming (Fig. 19A) and a low duty cycle of the maximum dimming (Fig. 19B); Fig. 20 is available to generate complex numbers Phase dimming control signal to control the plurality of LEDs of the LED bulb in FIG. a circuit diagram of a phase generator of the dimming; FIG. 21 is a circuit diagram of one of the synchronous phase frequency detectors (S-PFD) used in the phase generator of FIG. 20; and FIG. 22 is based on A diagram of an LED light bulb in accordance with an alternative embodiment of the present invention, wherein the LEDs of the LED bulb are connected in parallel. I: Embodiment 3 Detailed Description The exemplary embodiments of the present invention described below are described and illustrated in the context of solid state lighting, particularly power conversion and control methods and systems for LED lighting. However, it should be emphasized and understood that the power conversion and control methods of the present invention are not limited to LED lighting applications; they are suitable for other lighting and non-lighting applications that utilize other types of loads, including solid state (or non-solid) other than LEDs. Illumination device, and device that does not emit light but performs some other useful work 10 201220937. Referring to Figure 6, a light emitting diode (LED) bulb 600 in accordance with one embodiment of the present invention is illustrated. The LED bulb 600 includes a power conversion and control circuit 601. The power conversion and control circuit 6.1 includes an AC-to-DC converter (AC_DC) converter 602, a voltage divider 604, and an LED controller 60A; and an LED 608-1, 608-2,·.., 608-η, where "is an integer, indicating that [ED can include one or a plurality of LEDs. As will be explained in detail below, the AC_DC converter 6〇2 directly converts alternating current, such as that may be provided by an AC mains, to direct current. The voltage divider 604 divides the DC voltage Vdc of the DC power generated by the AC-DC converter 602 by a factor m, thereby generating one or a plurality of w separate power sources for supplying "LED 608-1, 608-2, _ .., 608-η. The factor m is an integer, and in one embodiment 'is an integer equal to the value of ". LED controller 606 includes one or more controlled current sources for controlling current through LEDs 608-1, 608-2, .., 608-n, and optionally, further including the use of a conventional A dimmer switch to control the dimming circuitry of LEDs 608-1, 608-2, ..., 608-n. In one embodiment of the invention, some or all of the various components of power conversion and control circuit 601 include a single integrated circuit (1C) wafer. In another embodiment, some or all of the various components of power conversion and control circuit 601 are included and distributed among two or more 1C wafers. However, it will be readily apparent to those skilled in the art that any number of 1C wafers, hybrid or discrete devices, and combinations thereof, can be used to implement the power conversion and control circuit 601 of the LED light bulb 600. The LEDs 608-1, 608-2, ..., 608-n of the LED bulb 600 are disposed in a transparent or translucent housing of 201220937, and the AC-DC converter 602, the voltage divider 604 and the LED controller 606 are integrated. At or connected to a socket that is compatible with a standardized receptacle or socket. For example, in one embodiment, the transparent or translucent outer casing includes a glass bulb 702, and the AC-DC converter 602, voltage divider 604, and LED controller 606 are coupled or integrated into an Edison threaded socket 704. Inside, as shown in Figure 7. It will be appreciated by those skilled in the art that other types of transparent or translucent outer casings (standardized or non-standardized) and other lampholder types (normalized or non-standardized) can be used. Thus, for the purposes of this disclosure, the term "LED bulb" means and encompasses an LED illumination device having either a housing of any type and a socket of either type. Figure 8 is a circuit diagram of an AC-DC converter 800 for implementing an AC-DC converter 602 of the LED bulb 600 of Figure 6 in accordance with an embodiment of the present invention. AC-DC converter 800 is similar to the AC-DC converter disclosed in U.S. Patent Application Serial No. 12/841,608, the disclosure of which is incorporated herein by reference in its entirety in Incorporate this disclosure. As shown in FIG. 8, the AC-DC converter 800 includes first, second, third, and fourth switches 802, 804, 806, and 808, an inductor 810, a smoothing capacitor 812, and a switch control. 814. The first switch 802 is coupled between one of the terminals of the AC input and the first terminal of the inductor 810; the second switch 804 is coupled between the first terminal of the inductor 810 and the opposite polarity terminal of the AC input; 806 is coupled between the AC input and the second terminal of the inductor 810; and the fourth switch 808 is coupled to the second of the inductor 810

S 12 201220937 Between the terminal and the positive DC output terminal. Depending on the comparison of the instantaneous AC input voltage version to the DC output voltage, the switch controller 814 generates a switch drive signal that controls the switching of the first, first, second and fourth switches 802, 804, 806 and 808 since use. More detailed instructions. In the embodiment of the present invention, the first, second, third, and fourth switches 802, 8G4, 8%, and 8G8 comprise an integrated circuit (1C) wafer based on a standard semiconductor process. A crystal (such as a metal oxide semiconductor % effect transistor (MOSFET) or a bipolar junction transistor (bjt)). Inductor 810 and capacitor 812 may also be integrated into one or more wafers, or either or both of these devices may be discrete devices coupled to external pins of the one or more IC wafers. Of course, other types of switching devices and semiconductor processes can be used. For example, conventional switches, diodes, repeaters or other semiconductor-based or non-semiconductor-based switching devices can be used, or compound semiconductor-based transistor devices, such as high electron mobility transistors (HEMT) or heterojunctions. A bipolar transistor (HBT) can be used to implement the first, second, third, and fourth switches 802, 8〇4, 8〇6, and 808 switches instead of the germanium MOSFET or BJT. For the purposes of this disclosure, the term "switch j" is used in its broadest sense to include all of these types of switches and any other suitable switching device. AC-DC converter 800 operates to convert an AC input voltage W« , such as can be provided by an AC mains, converted to a DC output voltage Vdc, without a bridge rectifier (ie, a diode bridge). Direct AC-to-DC conversion uses the switch controller 814 to control the first, second, and third The on-off states of the fourth switches 802, 804, 806, and 808 are completed. The switches 802, 804, 806, and 808 13 201220937 are turned on (closed), turned off (off) by a duty cycle of one of the D switch drive signals. Or driven by a complementary switch drive signal with a duty cycle of (丨-D), depending on the instantaneous AC input voltage W« compared to the DC output voltage Vdc. The switch drive signal and the complementary switch drive signal are switched by Controller 814 generates, and in one embodiment, has a common, fixed switching (i.e., "chopper") frequency / = 1 / T, where T is the switching period. In order to avoid the need for a large and expensive capacitor, the cutoff frequency of the switch controller is set to a high frequency of about 1 MHz or higher. As shown in the signal diagram in FIG. 9 and the switching table in FIG. 1 , when Vdc, the first switch 802 is driven by the switch drive signal with a duty cycle tON/T=D, and second. Switch 804 is driven by a complementary switch drive signal for one duty cycle (T-t0N) / T = (1D), third switch 806 is turned off, and fourth switch 808 is turned "on". When < -Vdc, the first switch 802 is turned off, the 'second switch 804 is turned on', the third switch 806 is driven by the switch drive signal by one duty cycle D, and the fourth switch is driven by the complementary switch by a duty cycle ( 1-D) is driven. Finally, when "greater than -Vdc but less than Vdc", that is, when < Vdc, the first, second, third, and fourth switches 802, 804, 8〇6, and 808 are all turned off. It can be appreciated by observing that the AC-DC converter 800 actually includes an integrated (i.e., coupled) buck converter and an inverting buck converter that the AC-DC converter 800 produces a DC output voltage vdc = D. When % > Vdc is in the positive half cycle of the AC input waveform, the third switch 806 is turned off, the fourth switch 8〇8 is turned on 'and the AC-DC converter 800 is turned into and acts as a buck converter 800A ' The one shown in Fig. 11A. In this configuration, the first and second open

14 201220937 The switches 802 and 804 act as high-side and low-side switches of the buck converter, respectively, and are driven by the switch drive signal with a duty cycle D and a complementary switch drive signal at a duty cycle (1-D). Therefore, the first and second switches 802 and 804 alternately configure the inductor 810 to store energy or supply current during the positive half cycle of the AC input voltage of > Vdc, and the DC output voltage Vdc = DFi > i. In the negative half cycle of the AC input waveform at W«<-Vdc, the first switch 802 is turned off, the second switch 8〇4 is turned on, and the AC_DC converter 8 is degenerated and acts as the so-called "reverse". The buck converter 8〇〇B is as shown in Figure iiB. In this configuration, the third and fourth switches 806 and 808 are respectively driven by the switch drive signal D and the complementary switch drive signal (1_D). In the negative half cycle of the AC input voltage at Kk<_Vdc, the inverting buck converter 8〇〇B converts the negative input voltage ^^, and the inductor 810 is switched by the switching action of the third and fourth switches 806 and 808. Alternately configured to store energy or supply current to produce an output voltage Vdc equal to Dh_»|. Therefore, in terms of positive and negative half cycles, the AC-DC converter 800 generates a DC output voltage vdc = D | In the above non-limiting embodiment, switch control circuit 814 controls the opening and closing of switches 8〇2, 804, 806, and 808 under all load conditions in accordance with the switching table in FIG. In another embodiment, the switch controller 814 is configured to cause the switch 808 to remain on under light load conditions, and the remaining switches 802, 804, and 806 are configured to operate in accordance with the switching table in FIG. Or configured to not switch at all. Thus, in this alternative embodiment, capacitor 812 acts as a DC power source under light load conditions. An important advantage of using AC-DC converter 8 is that it directly performs AC-DC conversion' With or without the use of a bridge rectifier or step-down transformer 15 201220937. This eliminates the need for a power factor correction pre-regulator circuit to compensate for the nonlinearity caused by the bridge rectifier. This advantage results in a lower An LED bulb 600 of the number of parts is relatively inexpensive to manufacture and can be designed to have a physical size (ie, a smaller form factor) that is much smaller than prior art LED bulbs. It also results in a more energy efficient, more reliable, and safer one. LED Bulb 600. In accordance with an embodiment of the present invention, each of the LEDs of the LED bulb of the present invention is self-disciplined and individually powered by a separate power source. The demonstration shown in Figure 6 In an embodiment, the layer of the present invention supplies LED bulbs 608-1, 608-2 by powering LEDs 600 by configuring voltage dividers 6〇4 to generate and provide a plurality of m separate Vdc/m voltages. ,.·.,608-η. The self-disciplined and independently powered LEDs 608-1, 608-2, .., 608-η allow the LED bulb 600 to be softly degraded, as if the LED 608-1, 608-2 One of the 608-n failures 'other LEDs still illuminate. Figure 12 is a circuit diagram of a charge pump voltage divider 1200 that can be used to generate a power supply provided by voltage divider 604. For the purposes of this description, assume that LED bulb 600 contains four LEDs (ie, "=4"' and four charge-based voltage dividers 1200 are correspondingly used to generate w=w=4 separate power supplies, each having A voltage Vdc/4. Of course, it will be understood by those skilled in the art that this is merely an example and that the LED bulb 600 is not limited to having four LEDs, and the charge pump voltage divider 1200 can be modified to produce other numbers w a power supply. As shown in Fig. 12, the charge pump voltage divider 12A includes a first set of switches 1202-b 1202-2, 1202-3, 1202-4; capacitors 1204-1, 1 204-2, 1204-3, 1204-4; a second set of switches 1206-1, 1206_2, 12〇6-3, 1206-4; and an oscillator 1208. The charge pump voltage divider 12〇〇 is configured to

16 201220937 LED 608-1 Power Supply 'LED 608-1 is driven by a controlled current source 1210. The controlled current source 1210 is energized and de-energized according to a dimmer signal DIM, which will be discussed in more detail below. . Substantially the same charge pump divider is utilized to generate electricity and supply power to the remaining LEDs 608-2, _.., 608-«. The first set of switches 1202-1, 1202-2, 1202-3' 1202-4 and the second set of switches 1206-1, 1206-2, 1206-3, 1206-4 are responsive to the periodic switching provided by the oscillator 1208 (i.e., state of charge) control signals CS and 交替 alternately configure capacitors 1204-1, 1204-2, 1204-3, and 1204-4 to be in a "charged" state and a "loaded" state. When in the charging state, the switches of the first group of switches 1202-b 1202-2, 1202-3, 1202-4 are all closed and the switches of the second group of switches are all disconnected, resulting in capacitors 1204-1, 12〇4_2, 1204 -3, 1204-4 are coupled in series, as shown in the charge state equivalent circuit in Figure 13A. Capacitors 1204-1, 1204-2, 1204-3, 1204-4 all have the same capacitance. Therefore, the DC voltage Vdc is evenly divided and distributed (Vdc/4) between the capacitors 1204-1, 1204-2, 1204-3, and 1204-4 connected in series. After the capacitors 1204-1, 1204-2, 1204-3, 1204-4 have been charged, the switch control signal CS and the laser cause the first group of switches 丨2〇2·Bu 1202-2, 12〇2_3, 1202-4 The second set of switches 1206-1' 1206-2, 1206-3, 1206-4 are closed, and the charge pump voltage divider 1200 is configured to be in a loaded state, as shown in the load state equivalent circuit of Figure 13B. By. In the load state, the charged, parallel-connected capacitors 1204-1, 1204-2, 1204-3, 1204-4 collectively supply power to the LED 608-1. In accordance with an embodiment of the invention illustrated in Figure 14, the LED bulb 600 of the present invention can be dimmed using a conventional TRIAC dimmer dimmer 17 201220937. The TRIAC dimmer switch 1402 is illustrated by a dashed box to emphasize that it is separate from the LED bulb 600 in this exemplary embodiment. However, in another embodiment, the TRIAC dimmer switch 14〇2 (or other similar dimmer switch) includes a portion of the LED light bulb 600. As explained above with reference to Figures 4 and 5 above, a triac dimmer distorts the AC input waveform' so that the average power output to the bulb is reduced. The TRIAC s illuminator switch itself does not provide an acceptable solution for controlling the dimming of the LED bulb of the present invention. However, the resulting distorted voltage waveform (i.e., the modified input voltage Kk) contains information that can be used to control dimming. As shown in Figure 15A, the modified input voltage provided by the TRIAC dimmer switch 1402 is substantially the same as the AC input voltage provided by the AC mains when dimming is not active. Under this condition, the 15B and 15C plots show a significant portion of the AC cycle period greater than Vdc or less than -Vdc, and the 15D plot shows that the fineness is less than Vdc only for a short period of time t1. However, when dimming is active and the TRIAC dimmer switch 1402 is acting and the waveform is distorted (see Figure 16A), the modified input voltage 'is still greater than Vdc or less than the shorter part of the -Vdc AC cycle (see Figures 16B and 16C) and |FW| remain less than Vdc for a longer duration t2, i.e., t2 > tl (see Figure 16D). In order to utilize this pulse-width versus dimming level dependence on the dimming of LEDs 608-1, 608-2, ..., 608-« controlling LED bulb 600, LED controller 606 of LED bulb 600 includes One of the comparison circuits 1700 shown in Figure 17 produces a logic signal 51 representing the time of < Vdc. The comparison circuit 1700 includes first and second comparators 1702 and 1704, an inverting amplifier 1706, 8 18 201220937, a first voltage divider including resistors 1708 and 1710 (or, optionally, a capacitor), and a resistor including A second voltage divider of transistors 1712 and 1714 (or, optionally, a capacitor), and a logic NOR gate 1716. The first and second voltage division writes may not necessarily depend on the acceptable input voltage range of the various amplifiers. However, if the modified AC input voltage KiV is not within the acceptable input range, then the first and second voltage dividers are used to reduce. Specifically, the first voltage divider reduces the modified input voltage to an adjusted, modified AC input voltage '' such that the voltage is within an acceptable input voltage range of the first and second comparators 1702 and 1704, And the second voltage divider adjusts the DC output voltage Vdc of the AC-DC converter 602 by the same amount to generate an adjusted DC output voltage aVdc. The first comparator 1702 compares the scaled, modified AC input voltage αΚ»' with the adjusted DC output voltage aVdc, generates a high output voltage when '>Vdc, and generates a low output voltage when Vdc . Inverting amplifier 1706 inverts the adjusted DC output voltage aVdc to produce an adjusted, inverted DC output voltage -aVdc. The second comparator 1704 compares the adjusted, inverted DC output voltage -aVdc with the adjusted, modified AC input voltage aPV, generates a high output voltage when Wn'<-Vdc, and when ***>_Vdc Produces a low output voltage. Finally, the NOR gate produces the desired logic signal 51' which has a logic high ("1") whenever it is '| < Vdc and has a logic low ("〇") at other times.

Logic signal 51 has a variable duty cycle that is dictated by the dimming setting of TRIAC dimmer switch 1402. According to an embodiment of the invention, the dependency is used to control the dimming of the LEDs 608-1, 608-2, ..., 608-n of the LED bulb 600, in particular by the pair of LEDs 19 201220937 608- The on-off ratio of l, 608-2, ..., 6〇8-n is compared to duty cycle control. However, because the logic signal has a low frequency that is only equal to the line frequency (6 Hz in the US), it is first upconverted to avoid any perceived discretion of the LEDs, as will be explained in more detail below. Although the logic signal 51 is generated in this exemplary embodiment based on the comparison circuit 1700 |f called <vdc, it should be noted that the logic signal ^ can be selectively based on the distortion waveform, other signals. Features such as, for example, a distorted waveform, a firing angle or a conductive angle are produced. Figure 18 is a circuit diagram of an exemplary frequency converter 1800 for converting duty cycle information in a logic signal s to a higher frequency. In an embodiment, it is included in the LED controller 606 of the LED bulb 600 and includes first and second digit counters 1802 and 1804, a latch 18〇6, and a digit size comparator 1808 «from the comparison circuit The 17-inch logic signal is coupled to the enable (εν) input of the first digital counter 1802. When the logic signal is a logic high, that is, when |F~|<Vdc, the first digital counter 18〇 2 starts counting from zero at a rate of 27 X 60 Hz. The first digit counter 18〇2 counts until the logic signal *S falls to a logic low, at which point the digit count is latched into the latch 1806 and coupled to the input Ββ second digit counter of the digital size comparator 18〇8 1804 is a free counter configured to continuously and repeatedly count from 〇 to 127, but at a rate much higher than the line rate of 6 Hz, allowing duty cycle information in the logic signal to be converted to a higher frequency fLED<> The fLED is set during design and is equal to 10 MHz in one embodiment. When the second digit counter 1804 counts, the digit comparator 1808 compares its count with the count of the latch 18〇6. Eventually, the count exceeds the count of latch 1806, causing the A>B output of digit 20 201220937 comparator 1808 to change to a logic high. The A>B output is maintained at a logic south until the second digit counter 18〇4 counts to its limit (27 -1 = 127). It then decreases and the second digit counter 18〇4 is reset to zero to restart counting. The A> B output signal of the digital comparator 1808 has a fixed high frequency fLED and a variable duty cycle that is dependent on the dimming level setting of the DIRAC dimmer switch 14〇2. For a minimum dimming setting, the duty cycle (t0N/t0FF) of the a>b signal is high, as shown in Figure 19A, and for a maximum dimming setting, the duty cycle is low, as in 19B The one shown in the figure. Therefore, the A>B signal can be used to control the adjustment of the LED bulb 600 in a large dimming range by simply controlling the on-off ratio of the LEDs 608-1, 608-2, . . ., 608-«. Light. According to an embodiment, the a > B signal is used as a "DIM (dimming)" signal to enable and disable one or more controlled currents of the LEDs 608-1, 608-2, ..., 608-« The source, similar to that shown in Figure 12, wherein the controlled current source 1210 of LED 608-1 is enabled and deactivated in response to the DIM signal and in accordance with the duty cycle of the DIM signal. Depending on the number of LEDs used in the LED bulb 600, switching the LEDs 608-1, 608-2, ..., 608-« simultaneously to on and off by the same DIM signal can result in an excessive load. In order to avoid this problem, in one embodiment of the present invention, "a dimming control signal having a different phase from each other is generated and used to individually control the conduction of π LEDs 608-1, 608-2, ..., 608-". - Cut-off ratio duty cycle control. Figure 20 is a circuit diagram of an exemplary phase generator 2000 that can be used to generate a dimming control signal. In one embodiment of the invention, 'phase generator 2000 includes a portion of LED control 21 201220937 controller 606 of LED bulb 600' and includes master-slave ring oscillators 2〇〇2 and 2〇〇4 (or other types of Multiphase oscillators and „Synchronous phase-frequency detectors (S-PFD) 2006-1, 2006-2,...,2006-«. A more detailed circuit diagram of the first-S-PFD 2006-1 is painted As shown in Fig. 21, the remaining s pFD 2006-2,...,2〇06-« are substantially the same. The main ring oscillator: the device 2002 is configured in a phase-locked loop 2008, which operates The output frequency of the main ring oscillator 2〇〇2 is locked to the print and the main phase reference is provided for phase comparison with the slave ring oscillator 2〇〇4. The digit size from the inverter 1800 (Fig. 18) The A>8 signal of the comparator 808 is used as a phase rotation command for shifting the phase of the slave ring oscillator 2004 with respect to the phase of the main ring oscillator 2〇〇2. s_pFE) 2006], 2006-2, ..., 2006-«Generate „dimming control signals privately” ice, wherein each dimming control signal has a phase with the phase of the master-slave ring oscillator 2〇〇2 The difference is proportional to the pulse width. An XOR gate 2〇1〇 compares the pulse width of one of the S-PFDs (S-PFD 2006-1 in this example) with the pulse width of the A> B signal. When the width fails to match, the X〇r gate 2〇1〇 generates a disturbance pulse. Over time, these disturbance pulses are averaged by the filter and the waver 2 to generate a disturbance signal for changing the slave oscillator 2电力4 power supply. Modifying the slave oscillator power supply affects the delay of the inverter in the slave ring oscillator 2004, and thus affects the phase of the slave ring oscillator 2〇〇4 relative to the main ring oscillator The phase relationship of the phase of 2002. In this way, the output of the S-PFD 2006-1, 2006-2, ..., 2006-« „dimming control signals 九&,... the pulse width in the ice responds to The modified power supply is changed, forcing "the dimming control signal H·., each of the working weeks 22 201220937 to adapt to and track the change in the duty cycle of the A > B signal. In an exemplary embodiment, the LEDs 680-1, 608-2, ..., 608-« of the LED bulb 600 are comprised of The w separate power supplies provided by voltage divider 604 are separately powered. In an alternate embodiment, LEDs 608-1, 608-2, ..., 608-« are connected in parallel and powered by a single power supply, as in the first 22 is generally shown in the LED bulb 2200. The AC-DC converter 602 operates similarly to the above described 'LED 608-1, 608-2, _.., 608-« parallel connection to allow for flexible degradation, similar For LED bulbs 600. A DC-DC converter 2202 converts the DC output voltage Vdcl into a lower DC voltage vdc2 for LEDs 608-1, 608-2, ..., 608-". Alternatively, if the AC-DC converter 602 is low The output voltage is not limited by the duty cycle, which may be configured to convert the AC input voltage Fm directly to Vdc2, ie without the aid of an intermediate DC-DC converter 2202. Similar to the LED controller 6〇6 above, the LED controller 22〇4 includes circuitry for collectively or individually controlling dimming of LEDs 608-1, 608-2, . . . , 608-«, including support circuitry for controlling dimming in response to conventional TRIAC dimmer switches Although various embodiments of the invention have been described, the invention has been described by way of example and not limitation. The scope of the present invention should not be limited by the details of the exemplary embodiments of the present invention. Including such (four) = patent scope The equal scope of the rights is determined. [Simplified illustration] 23 201220937 Figure 1 is a diagram of a prior art LED bulb; Figure 2 is an input line voltage applied to the prior art LED of Figure 1. F/« and a signal diagram of the input line current /ί>ζ extracted from the AC mains; Figure 3 is a diagram of a prior art LED bulb equipped with a power factor correction (PFC) pre-regulator; Figure 4 A circuit diagram of a conventional phase control (ie, a TRIac dimmer switch); FIGS. 5A and 5B are line voltage and dimming waveforms associated with the TRIAC dimmer switch of FIG. 4; Figure 6 is a diagram of an LED bulb according to an embodiment of the present invention; Figure 7 is a diagram of the LED bulb of Figure 6, showing how the LED of the LED bulb is surrounded by a transparent or a half How the electrical components of the LED bulb are coupled to a standard Edison threaded socket in a transparent housing; Figure 8 is an AC-to-DC (AC-) for implementing the AC-DC converter of the LED bulb of Figure 6. a circuit diagram of the DC converter; Figure 9 is the supply of the AC-DC conversion in Figure 8. The AC input voltage «, and a signal diagram of its relationship with the DC voltage VdcA generated by the output of the AC-DC converter, inverting -Vdc; Figure 10 is a diagram showing the AC-DC conversion in Figure 8. A table of how the switch of the device switches and drives depending on the instantaneous value of the AC input voltage W« and the DC voltage Vdc generated by the output of the AC-DC converter in FIG. 8 and its inversion-Vdc; The figure is a circuit diagram showing how the AC-DC converter in Figure 8 is converted to a buck converter in the positive half cycle of the AC input waveform at Κζ·«> Vdc 24 201220937 time; The figure shows a circuit diagram of how the AC-DC converter in Fig. 8 is turned into and acts as an inverting buck converter in the negative half cycle time of the AC input waveform at < - Vdc; A circuit diagram of a charge pump voltage divider that can be used to implement a voltage divider in the LED bulb of FIG. 6; FIG. 13A is a diagram of the charge pump voltage divider of FIG. 12 being configured to be in a "charged" state A simplified equivalent circuit diagram of the charge pump voltage divider; Figure 13B is the charge pump of Figure 12 A simplified equivalent circuit diagram of the charge pump divider when configured in a "load" state; Figure 14 is a diagram showing how the dimming of the LED of the LED bulb in Figure 6 can be adjusted by a conventional TRIAC A diagram of the light switch control; Figure 15A-D is a signal diagram associated with the operation of the LED bulb of Figure 6 when the TRIAC dimmer switch of Figure 14 is inactive; 16A-D Figure is a signal diagram associated with the operation of the LED bulb in Figure 6 when the TRIAC dimmer switch in Figure 14 is active; Figure 17 is a comparison of the dimming of the trjac dimmer switch in Figure 14 a comparison circuit between the waveform and the DC voltage output by the AC-DC converter; Figure 18 is a frequency converter that can be used to convert the duty cycle information in the logic signal from the comparison circuit in FIG. 17 to a higher frequency. A circuit diagram; 19A and 19B are diagrams showing how a DIM signal generated by the frequency converter of Fig. 18 has a minimum duty cycle (Fig. 19A) and 25 201220937 a minimum duty cycle of maximum dimming (Fig. 19B) signal diagram; Fig. 20 is available to generate complex numbers A circuit diagram of a phase generator of the same phase dimming control signal for controlling the dimming of the plurality of LEDs of the LED bulb in FIG. 6; FIG. 21 is a synchronous phase frequency used in the phase generator of FIG. A circuit diagram of one of the detectors (S-PFD); and FIG. 22 is a diagram of an LED bulb in accordance with an alternative embodiment of the present invention, wherein the LEDs of the LED bulb are connected in parallel. [Main component symbol description] 100.. . Prior art LED bulb / LED bulb 102.. Bridge rectifier 104... Straddle capacitor 106.. DC to DC converter 108...LED string 3 00..丄ED bulb/previous Technical LED Bulb 302.. Power Factor Correction (PFC) Pre-Regulator / PFC Pre-Regulator 400.. Known Dimmer Switch / TRIAC Dimmer Switch 402.. Variable Resistor 404.. . Capacitor 406.. .DIAC (AC Diode) 408.. .TRIAC (AC Triode) 410.. . Incandescent Bulb 512.. . Conduction Delay 600...Light Emitting Diode (LED) Bulb / LED Bulb 26 201220937 601.. Power conversion and control circuit 602.. AC to DC converter (AC-DC) converter / AC-DC converter 604.. . Voltage divider

606.. 丄 ED controller 608-1 ~ 608-n. " LED 702.. . glass bulb 704.. Edison threaded socket 800.. . AC-DC converter 800A... buck converter 800B ... "reverse" buck converter 802... first switch / switch 804.. second switch / switch 806.. third switch / switch 808 ... fourth switch / switch 810.. inductor 812 .. . Straddle capacitor / capacitor 814.. Switch controller / switch control circuit 1200.. Charge pump divider 1202-1 ~ 1202-4... The first group of switches 1204-1 ~ 1204-4.. Capacitors 1206-1~1206-4...Second Group Switch 1208.. Oscillator 1210.. Controlled Current Source 1402.. Known TRIAC (AC Triode) Dimmer Switch / TRIAC Dimmer switch 27 201220937 1700... comparison circuit 1702... first comparator 1704... second comparator 1706.. reverse amplifier 1708, 1710, 1712, 1714 ... resistor 1716.. logical NOR gate 1800. . Exemplary Inverter/Inverter 1802.. First Digit Counter 1804... Second Digit Counter 1806.. Latch 1808.. Digit Size Comparator/Digital Comparator 2000.. Exemplary Phase Generation 2002... master-slave ring vibration Device

2004.. Subordinate Ring Oscillator/Slave Oscillator 2006-1~2006-n...Synchronous Phase Frequency Detector (S-PFD) 2006-1...Synchronous Phase Frequency Detector (S-PFD)/First S-PFD 2008.. . phase-locked loop 2010.. .XOR gate 2012.. filter 2200.. 丄ED bulb 2202.. DC-DC converter 2204...LED controller 28

Claims (1)

201220937 VII. Patent application scope: 1. An illumination system comprising: one or more illumination devices; and an AC-to-DC converter configured to directly use a bridge rectifier The alternating current of the alternating current source is converted to direct current, which is used to power the one or more lighting devices. 2. The illumination system of claim 1, wherein the AC-DC converter comprises a plurality of switches. 3. The illumination system of claim 1 or 2, wherein the AC-DC converter is configured to directly convert the alternating current to direct current using a step-down transformer. 4. The illumination system of claim 1-3, further comprising circuitry configured to generate a plurality of DC power sources from the DC power, the plurality of DC power sources configured to supply power to the one or more illumination devices. 5. The illumination system of claim 1, further comprising a control circuit configured to generate one or more dimming control signals for controlling dimming of the one or more illumination devices. The illumination system of claim 5, wherein the control circuit is configured to change a duty cycle of the one or more dimming control signals while controlling dimming of the one or more illumination devices. 7. The illumination system of claim 6, wherein the control circuit is configured to change the operation of the one or more dimming control signals in response to a dimming signal provided by an external dimmer switch cycle. 8. The illumination system of claim 7, wherein the control circuit 29 201220937 includes a channel configured to compare a voltage of the dimming signal with the DC current when the one or more dimming control signals are generated One of the voltage comparison circuits. 9. The illumination system of claim 5, wherein the one or more illumination devices comprise a plurality of illumination devices and the control circuit is configured to generate a plurality of dimming controls for controlling dimming of the plurality of illumination devices signal. 10. A power conversion and control system for an electrical load, comprising: an alternating current to direct current (AC-DC) converter configured to convert alternating current from an alternating current source to direct current; A device in which a direct current of an AC-DC converter is supplied to an electrical load; and a device for duty cycle control of a current passing through the electrical load. 11. The power conversion and control system of claim 10, wherein the AC-DC converter is configured to directly convert an alternating current from the alternating current source to a direct current using a bridge rectifier or a step-down transformer. . 12. The power conversion and control system of claim 10, wherein the electrical load comprises one or more illumination devices, and wherein the means for duty cycle control comprises responding to an external dimming A dimming signal provided by the switch is used to control the current through the one or more illumination devices. 13. The power conversion and control system of claim 12, wherein the one or more illuminating devices in the 201220937 comprise a plurality of illuminating devices, and the device for controlling the current duty cycle comprises generating Means for controlling the dimming of the plurality of dimming control signals of the plurality of illumination devices. 14. A method of illumination comprising the steps of: using a plurality of switches without the need to directly convert alternating current (AC) electricity into direct current (DC) power using a bridge rectifier or step-down transformer; and using the directly converted direct current to supply power to One or more light emitting devices. 15. The illumination method of claim 14, wherein the direct conversion of the direct current power to the one or more illumination devices comprises the steps of: generating a plurality of separate DC power sources from the directly converted direct current; and using The plurality of separate DC power sources supply power to the one or more lighting devices. 16. The method of illumination of claim 14, further comprising controlling dimming of the one or more illumination devices. 17. The illumination method of claim 16, wherein the one or more illumination devices comprise a plurality of illumination devices, and controlling dimming of the plurality of illumination devices comprises generating dimming for controlling the plurality of illumination devices. Complex dimming control signals. 18. The illumination method of claim 17, wherein generating the complex dimming control signal comprises generating a complex phase offset dimming control signal. 19. The illumination method of claim 16, wherein the dimming controlling the one of the 31 201220937 or the plurality of illumination devices is performed in response to a dimming signal provided by an external dimmer switch. 20. An illumination system comprising: a plurality of illumination devices; an alternating current to direct current (AC-DC) converter configured to generate direct current from an alternating current supplied by an alternating current source; and a voltage divider configured to The direct current generated by the AC-DC converter generates a plurality of direct current power sources configured to supply power to the plurality of light emitting devices. 21. The illumination system of claim 20, wherein the AC-DC converter is configured to directly convert alternating current to direct current using a bridge rectifier. 22. The illumination system of claim 20, wherein the AC-DC converter comprises: an inductor; a capacitor; and a plurality of switches configured to selectively convert the alternating current to direct current The capacitor is coupled and decoupled from the inductor. 23. The illumination system of claim 22, wherein the inductor, capacitor, and switch are configured as a buck converter when one of the AC power sources has a voltage greater than the DC voltage Vdc. 24. The illumination system of claim 23, wherein the inductor, capacitor, and switch are configured as a reverse buck converter when one of the AC power sources has a voltage less than -Vdc. The illumination system of claim 20, further comprising a control circuit configured to generate one or more dimming control signals for controlling dimming of the plurality of illumination devices. 26. The illumination system of claim 25, wherein the control circuit is configured to change a duty cycle of the one or more dimming control signals while controlling dimming of the plurality of illumination devices. 27. The illumination system of claim 26, wherein the control circuit is configured to change the one or more dimming control signals in response to a dimming signal provided by an external dimmer switch Working period. 28. The illumination system of claim 27, wherein the control circuit comprises: configured to compare a voltage of the dimming signal with a DC of the direct current when the one or more dimming control signals are generated Voltage comparison circuit. 29. The illumination system of claim 25, wherein the one or more dimming control signals comprise a plurality of dimming control signals, and the control circuit is configured to control the plurality of dimming control signals using the plurality of dimming control signals Dimming of the illuminating device. 30. A power conversion and control system for a lighting load having a plurality of lighting devices, comprising: an alternating current to direct current (AC-DC) converter configured to generate direct current from an alternating current provided by an alternating current source And a voltage divider configured to generate a plurality of direct current power sources by the direct current generated by the AC-DC converter, the plurality of direct current power sources being configured to supply power to the plurality of light emitting devices. The power conversion and control system of claim 30, wherein the AC-DC converter is configured to directly convert the alternating current into direct current using a bridge rectifier. 32. The power conversion and control system of claim 30, wherein the AC-DC converter comprises: an inductor; a capacitor; and a plurality of switches configured to convert alternating current to direct current The capacitor is coupled and decoupled from the inductor. 33. The power conversion and control system of claim 32, wherein the inductor, the capacitor Is', and the switch are configured as a buck converter when a voltage of the AC power source is greater than the DC voltage Vdc. 34. The power conversion and control system of claim 33, wherein the inductor, capacitor, and switch are configured as a reverse buck converter when one of the AC power sources has a voltage less than -Vdc. 35. The power conversion and control system of claim 30, further comprising a control circuit configured to generate a plurality of dimming control signals for controlling dimming of the plurality of illumination devices. 36. The power conversion and control system of claim 35, wherein the control circuit is configured to change a duty cycle of the dimming control signals while controlling dimming of the plurality of illumination devices. 37. The power conversion and control system of claim 36, wherein the control circuit is configured to change the dimming control signal in response to a dimming signal provided by an external dimmer switch Work week 34 201220937 period. 38. The power conversion and control system of claim 37, wherein the control circuit comprises: configured to compare a voltage of the dimming signal with a DC of the direct current when the complex dimming control signal is generated Voltage comparison circuit. 39. The power conversion and control system of claim 35, wherein the control circuit is further configured to generate the plurality of dimming control signals such that the dimming control signals have different phases from each other. 40. A method of illumination comprising the steps of: converting alternating current (AC) power to direct current (DC) power; generating a plurality of direct current power sources from the direct current; and supplying power to the plurality of light emitting devices from the plurality of direct current power sources. 41. The method of illumination of claim 40, wherein converting the alternating current to direct current comprises using a plurality of switches and directly converting the alternating current to direct current using a bridge rectifier or step-down transformer. 42. The illumination method of claim 40, further comprising generating a plurality of dimming control signals for controlling dimming of the plurality of illumination devices. 43. The method of illumination of claim 42, further comprising changing a duty cycle of the dimming control signals in response to a dimming signal provided by an external dimmer switch. 44. The illumination method of claim 42, further comprising comparing a voltage of the dimming signal with a DC of the DC generated by the AC-DC conversion when the complex dimming control signal is generated Voltage. The illumination method of claim 42, wherein the generating the plurality of dimming control signals is performed such that the dimming control signals have different phases from each other. 46. An illumination system comprising: a plurality of illumination devices; an alternating current to direct current (AC-DC) converter configured to generate direct current from an alternating current provided by an alternating current source; and a voltage divider configured to The DC power generated from the AC-DC converter generates a plurality of DC power sources configured to supply power to the plurality of light emitting devices. 47. The illumination system of claim 46, wherein the AC-DC converter is configured to directly convert alternating current to direct current using a bridge rectifier. 48. The illumination system of claim 46, wherein the AC-DC converter comprises: an inductor; a capacitor; and a plurality of switches configured to selectively convert the alternating current to direct current The capacitor is coupled and decoupled from the inductor. 49. The illumination system of claim 48, wherein the inductor, capacitor, and switch are configured as a buck converter when one of the AC power sources has a voltage greater than the DC voltage Vdc. 50. The illumination system of claim 49, wherein the inductor, capacitor, and switch are configured as an inverting buck converter when one of the alternating current sources has a voltage less than -Vdc 36 201220937. 51. The illumination system of claim 46, further comprising a control circuit configured to generate one or more dimming control signals for controlling dimming of the plurality of illumination devices. The illumination system of claim 51, wherein the control circuit is configured to change a duty cycle of the one or more dimming control signals while controlling dimming of the plurality of illumination devices. 53. The illumination system of claim 52, wherein the control circuit is configured to change the one or more dimming control signals in response to a dimming signal provided by an external dimmer switch Working period. 5. The illumination system of claim 5, wherein the control circuit comprises: configured to compare a voltage of the dimming signal with the DC current when the one or more dimming control signals are generated A DC voltage comparison circuit. 5. The illumination system of claim 51, wherein the one or more dimming control signals comprise a plurality of dimming control signals, and the control circuit is configured to control the using the plurality of dimming control signals Dimming of a plurality of illuminating devices. 56. A power conversion and control system for an illumination load having a plurality of illumination devices, comprising: an alternating current to direct current (AC-DC) converter configured to generate direct current from an alternating current provided by an alternating current source And a voltage divider configured to generate a plurality of DC power sources from the DC power generated by the AC-DC converter, the plurality of DC power sources being configured to supply power to the plurality of illumination devices at 201220937. 57. The power conversion and control system of claim 56, wherein the AC-DC converter is configured to directly convert alternating current to direct current using a bridge rectifier. 58. The power conversion and control system of claim 56, wherein the AC-DC converter comprises: an inductor; a capacitor; and a plurality of switches configured to convert alternating current to direct current The capacitor is coupled and decoupled from the inductor. 59. The power conversion and control system of claim 58 wherein the inductor, capacitor, and switch are configured as a buck converter when one of the AC power sources is greater than the DC voltage Vdc. 60. The power conversion and control system of claim 59, wherein the inductor, capacitor, and switch are configured as a reverse buck converter when one of the AC power sources has a voltage less than -Vdc. 61. The power conversion and control system of claim 56, further comprising a control circuit configured to generate a plurality of dimming control signals for controlling dimming of the plurality of illumination devices. 62. The power conversion and control system of claim 61, wherein the control circuit is configured to change a duty cycle of the dimming control signals while controlling dimming of the plurality of illumination devices. 63. The power conversion and control system of claim 62, wherein the control circuit is configured to change the dimming control in response to a dimming signal provided by an external dimmer switch 38 201220937 The duty cycle of the signal. 64. The power conversion and control system of claim 63, wherein the control circuit comprises: configured to compare a voltage of the dimming signal with a DC of the direct current when the complex dimming control signal is generated Voltage comparison circuit. 65. The power conversion and control system of claim 61, wherein the control circuit is further configured to generate the plurality of dimming control signals such that the dimming control signals have different phases from each other. 66. A method of illumination comprising the steps of: converting alternating current (AC) power to direct current (DC) power; generating a plurality of direct current power sources from the direct current; and supplying power to the plurality of light emitting devices from the plurality of direct current power sources. 67. The method of illumination of claim 66, wherein converting the alternating current to direct current comprises converting the alternating current to direct current using a plurality of switches and using a bridge rectifier or step-down transformer. 68. The illumination method of claim 66, further comprising generating a plurality of dimming control signals for controlling dimming of the plurality of illumination devices. 69. The illumination method of claim 23, further comprising changing a duty cycle of the dimming control signals in response to a dimming signal provided by an external dimmer switch. 70. The illumination method of claim 68, further comprising comparing one of the dimming signals to a voltage when the complex dimming control signal is generated 39 201220937 and the DC generated by the AC-DC conversion One of the DC voltages. The illumination method of claim 68, wherein generating the complex dimming control signal is performed such that the dimming control signals have different phases from each other. 40