Showing papers on "Inductor published in 2010"

A New Feedback Method for PR Current Control of LCL-Filter-Based Grid-Connected Inverter

Abstract: For a grid-connected converter with an LCL filter, the harmonic compensators of a proportional-resonant (PR) controller are usually limited to several low-order current harmonics due to system instability when the compensated frequency is out of the bandwidth of the system control loop. In this paper, a new current feedback method for PR current control is proposed. The weighted average value of the currents flowing through the two inductors of the LCL filter is used as the feedback to the current PR regulator. Consequently, the control system with the LCL filter is degraded from a third-order function to a first-order one. A large proportional control-loop gain can be chosen to obtain a wide control-loop bandwidth, and the system can be optimized easily for minimum current harmonic distortions, as well as system stability. The inverter system with the proposed controller is investigated and compared with those using traditional control methods. Experimental results on a 5-kW fuel-cell inverter are provided, and the new current control strategy has been verified.

Simplest chaotic circuit

Abstract: A chaotic attractor has been observed with an autonomous circuit that uses only two energy-storage elements: a linear passive inductor and a linear passive capacitor. The other element is a nonlinear active memristor. Hence, the circuit has only three circuit elements in series. We discuss this circuit topology, show several attractors and illustrate local activity via the memristor's DC vM - iM characteristic.

Circuits and methods for driving light sources

Abstract: A driving circuit includes a first inductor coupled in series with a light source for providing power to the light source. A controller coupled to the first inductor can control a switch coupled to the first inductor, thereby controlling a current flowing through the first inductor. A current sensor coupled to the first inductor can provide a first signal indicative of the current flowing through the first inductor, regardless of whether the switch is on or off. The switch is controlled according to the first signal. A second inductor magnetically coupled to the first inductor is also electrically coupled to the first inductor via a common node between the switch and the first inductor for providing a reference ground for the controller. The reference ground is different from the ground of the driving circuit.

A high power density single phase PWM rectifier with active ripple energy storage

Abstract: It is well known that there exist second-order harmonic current and corresponding ripple voltage on dc bus for single phase PWM rectifiers. The low frequency harmonic current is normally filtered using a bulk capacitor in the bus which results in low power density. This paper proposed an active ripple energy storage method that can effectively reduce the energy storage capacitance. The feed-forward control method and design considerations are provided. Simulation and 15kW experimental results are provided for verification purposes.

Parameter design principle of the arm inductor in modular multilevel converter based HVDC

Abstract: This paper describes two distinctive functions of the arm inductor in the modular multilevel converters (MMC): suppressing the circulating current and limiting the fault current rise rate. Based on the equality of the instantaneous power, the characteristics of the circulating current are analyzed and demonstrated that it flows through the three phase of the converter in negative sequence at double-fundamental frequency. The relationship between the amplitude of the circulating current and the value of the arm inductor is discussed, and the first principle to design the parameters is proposed. The second principle to design the parameters is based on the calculation of the fault current rise rates, with different values of the arm inductors. A detailed PSCAD/EMTDC model of MMC is developed. Steady state simulation proves the existence of the circulating current at double fundamental frequency. Simulation results show a close agreement with the calculation of the circulating current, with different arm inductor parameters. The fault between the DC terminals of the converter is investigated; the results verify the above parameter design principles of the arm inductor.

LLC Resonant Converter With Adaptive Link-Voltage Variation for a High-Power-Density Adapter

Abstract: The output voltage of an adapter for a laptop computer should vary according to the load current in order to supply power to the computer To satisfy this requirement, an LLC resonant converter with an adaptive link-voltage-variation (ALVV) scheme is proposed in this letter The proposed ALVV scheme helps the LLC resonant converter to operate at a nearly constant resonant frequency and also allows for the optimal design of the converter High power density and high efficiency can therefore be obtained The proposed LLC resonant converter with the ALVV scheme is analyzed theoretically and verified experimentally

Revisit of series-SSHI with comparisons to other interfacing circuits in piezoelectric energy harvesting

Abstract: SSHI (synchronized switch harvesting on inductor) techniques have been demonstrated to be capable of boosting power in vibration-based piezoelectric energy harvesters. However, the effect of frequency deviation from resonance on the electrical response of an SSHI system has not been taken into account from the original analysis. Here an improved analysis accounting for such an effect is proposed to investigate the electrical behavior of a series-SSHI system. The analytic expression of harvested power is proposed and validated numerically. Its performance evaluation is carried out and compared with the piezoelectric systems using either the standard or parallel-SSHI electronic interfaces. The result shows that the electrical response of an ideal series-SSHI system is in sharp contrast to that of an ideal parallel-SSHI system. The former is similar to a strongly coupled electromechanical standard system operated at the open circuit resonance, while the latter is analogous to that operated at the short circuit resonance with different magnitudes of matching impedance. In addition, the performance degradation due to non-ideal voltage inversion is also discussed. It shows that a series-SSHI system avails against the standard technique in the case of medium coupling, since its peak power is close to the ideal optimal power and the reduction in power is less sensitive to frequency deviation. However, the consideration of inevitable diode loss in practical devices favors the parallel-SSHI technique, since the frequency-insensitive feature is much more pronounced in parallel-SSHI systems than in series-SSHI systems.

Generalized multi-cell switched-inductor and switched-capacitor Z-source inverters

Abstract: High performance voltage and current-source inverters (VSI and CSI) are widely required in various industrial applications such as servo-motor drives, special power supplies, distributed power systems and hybrid electric vehicles. However, the traditional VSI and CSI have been seriously restricted due to their narrow obtainable output voltage range, short-through problems caused by misgating and some other theoretical difficulties due to their bridge-type structures. The Z-source inverter was proposed to overcome the problems associated with the traditional inverters, in which the functions of the traditional dc-dc boost converter and the bridge-type inverter have been successfully combined. To further widen the operational range or gain of the Z-source inverter in both the voltage and current type configurations, the generalized switched-inductor and switched-capacitor impedance networks are proposed hereon. Both simulation and experimental testing have been conducted for validating the extra boosting introduced with some representative results captured and presented near the end of the paper.

Highly Efficient High Step-Up Converter for Fuel-Cell Power Processing Based on Three-State Commutation Cell

Abstract: The interest toward the application of fuel cells is increasing in the last years mainly due to the possibility of highly efficient decentralized clean energy generation. The output voltage of fuel-cell stacks is generally below 50 V. Consequently, low-power applications with high output voltage require a high gain for proper operation. Several solutions were so far proposed in the literature, ranging from the use of high-frequency transformers to capacitive multipliers. This paper proposes the modification of a boost converter operating with a three-state commutation cell that is already well suited for high current stress in the input due to the current sharing between the active switches. Here, an additional winding is added to the autotransformer to provide not only the required high gain but also to significantly reduce the voltage stress across the active switches. Moreover, by employing the three-state switching cell, the size of the inductor is reduced because the operating frequency is double of the switching frequency. A prototype for the verification of the circuit was built for a 30-45-V input-voltage range, 400-V output voltage, and 250-W output power. The operation is evaluated, and the experimental waveforms and efficiency curves are presented.

Zero-Current-Switching Multilevel Modular Switched-Capacitor DC–DC Converter

Abstract: This paper presents a quasi-resonant technique for multilevel modular switched-capacitor dc-dc converter (MMSCC) to achieve zero-current switching (ZCS) without increasing cost and sacrificing reliability. This ZCS-MMSCC employs stray inductance distributed in the circuit as the resonant inductor to resonate with the capacitor and provide low dv /dt and di /dt switching transition for the device. The ZCS-MMSCC does not utilize any additional components to achieve ZCS and meanwhile solves the current and voltage spike problem during the switching transition, thus leading to reliable and high-efficiency advantages over traditional MMSCC. Furthermore, the ZCS-MMSCC reduces the capacitance needed in the circuit to attain high efficiency. In this case, the bulky capacitor bank with high capacitance in a traditional MMSCC to reduce voltage difference and achieve high efficiency is no longer necessary. A 150-W four-level ZCS-MMSCC prototype has been built. Simulation and experimental results are given to demonstrate the validity and features of the proposed soft-switching switched-capacitor circuit.

Modeling of ${\rm V}^{2}$ Current-Mode Control

Abstract: Recently, V2 constant on-time control has been widely used to improve light-load efficiency. In the V2 implementation, the nonlinear PWM modulator is much more complicated than usual, since not only is the inductor current information fed back to the modulator but also the capacitor voltage ripple information. Generally speaking, there is no subharmonic oscillation in constant on-time control. However, the delay due to the capacitor ripple results in subharmonic oscillation in V2 constant on-time control. So far, there has been no accurate model to predict the instability issue due to the capacitor ripple. This paper presents a new modeling approach for the V2 constant on-time control. The power stage, the switches, and the PWM modulator are treated as a single entity and modeled based on the describing function method. The model for the V2 constant on-time control achieved by the new approach can accurately predict subharmonic oscillations. Two solutions are discussed to solve the instability issue. The extension of the model to other types of V2 current-mode control and multiphase application is also shown in this paper. Simulation and experimental results verify the proposed model.

1.05-GHz CMOS oscillator based on lateral- field-excited piezoelectric AlN contour- mode MEMS resonators

Abstract: This paper reports on the first demonstration of a 1.05-GHz microelectromechanical (MEMS) oscillator based on lateral-field-excited (LFE) piezoelectric AlN contourmode resonators. The oscillator shows a phase noise level of -81 dBc/Hz at 1-kHz offset frequency and a phase noise floor of -146 dBc/Hz, which satisfies the global system for mobile communications (GSM) requirements for ultra-high frequency (UHF) local oscillators (LO). The circuit was fabricated in the AMI semiconductor (AMIS) 0.5-?m complementary metaloxide- semiconductor (CMOS) process, with the oscillator core consuming only 3.5 mW DC power. The device overall performance has the best figure-of-merit (FoM) when compared with other gigahertz oscillators that are based on film bulk acoustic resonator (FBAR), surface acoustic wave (SAW), and CMOS on-chip inductor and capacitor (CMOS LC) technologies. A simple 2-mask process was used to fabricate the LFE AlN resonators operating between 843 MHz and 1.64 GHz with simultaneously high Q (up to 2,200) and kt 2 (up to 1.2%). This process further relaxes manufacturing tolerances and improves yield. All these advantages make these devices suitable for post-CMOS integrated on-chip direct gigahertz frequency synthesis in reconfigurable multiband wireless communications.

Digital Average Current-Mode Control of PWM DC–DC Converters Without Current Sensors

Abstract: This paper introduces a digital average current-mode control technique for pulsewidth modulation dc-dc converters which only rely on voltage sampling. The proposed approach is to estimate inductor current using first-order discrete-time low-pass filter; therefore, the controller can calculate average inductor current in every switching cycle. As a novel technique of predictive average current control, it has been investigated by choosing an appropriate duty ratio to regulate valley inductor current first and then eliminating error between the estimated average inductor current and a reference current in succedent switching cycle. The algorithm is based on a two-loop control structure to achieve an accurate voltage regulation and is derived for three basic converters: buck, boost, and buck-boost. The validity of the proposed approach has been demonstrated by simulation and experimental results on a dc-dc boost converter.

Interleaved Triangular Current Mode (TCM) resonant transition, single phase PFC rectifier with high efficiency and high power density

Abstract: This paper presents a new topology for a highly compact and highly efficient single-phase Power Factor Corrected (PFC) rectifier system. The new topology consists of several interleaved boost stages which operate in a mode called Triangular Current Mode (TCM) in order to simultaneously achieve a high power density as well as a high efficiency. Applying TCM, ZVS is achieved over the full mains period by proper control of the power MOSFETs. The high TCM inductor current ripple is not transferred to the mains as the superposition of all boost cell input currents results in a smooth mains current waveform. Furthermore, one bridge leg operates synchronously to the mains frequency and connects the mains directly to an output rail. This results in very low common mode noise and only a small common mode filter has to be considered. The excellent behavior of this topology also applies to inverter operation.

Series-Resonant Multiinverter for Multiple Induction Heaters

Abstract: Multiple-load and multiple-source systems are widely present in the current technology. These systems require controlling either the supplied voltage or power to several loads with different requirements simultaneously. As a consequence, the cost and size of the power stage may increase beyond the admissible limits for certain applications. Considering multiple-inductor loads, a novel series-resonant multiinverter topology is proposed to obtain a cost-effective and high-power density solution. The converter is based on a common inverter block and a resonant-load block. The performed analysis includes the description of the operation modes and the control strategy analysis. Domestic induction heating has been considered for application due to its special cost and size requirements, and the extensive inductor use. The proposed converter has been designed and validated experimentally through a prototype, which includes the power converter and the field-programmable gate array-based control architecture.

Analysis and Design of a Nonisolated Bidirectional ZVS-PWM DC–DC Converter With Coupled Inductors

Abstract: A new zero-voltage-switched bidirectional dc-dc converter with coupled inductors is proposed in the paper. The proposed converter can operate with a steep conversion ratio, soft switching, a continuous inductor current, and fixed switching frequency. It can also operate with the switch stresses of a conventional pulsewidth-modulation-tapped/coupled-inductor converter regardless of the direction of power flow and without any voltage spikes across the switches during turn-OFF. These features are due to a very simple auxiliary circuit that is operational regardless of the direction of power flow and absorbs energy from the leakage inductance of the coupled inductors during switch turn-OFF. In the paper, the operation and design of the converter are discussed and its feasibility is confirmed with experimental results obtained from a prototype.

Design and Application for PV Generation System Using a Soft-Switching Boost Converter With SARC

Abstract: In order to improve the efficiency of energy conversion for a photovoltaic (PV) system, a soft-switching boost converter using a simple auxiliary resonant circuit, which is composed of an auxiliary switch, a diode, a resonant inductor, and a resonant capacitor, is adopted in this paper. The conventional boost converter decreases the efficiency because of hard switching, which generates losses when the switches are turned on/off. During this interval, all switches in the adopted circuit perform zero-current switching by the resonant inductor at turn-on, and zero-voltage switching by the resonant capacitor at turn-off. This switching pattern can reduce the switching losses, voltage and current stress of the switching device. Moreover, it is very easy to control. In this paper, we have analyzed the operational principles of the adopted soft-switching boost converter, and it is designed for PV generation system. Simulation and experimental results are presented to confirm the theoretical analysis.

Power factor correction circuit and driving method thereof

Abstract: The present invention relates to a power factor correction circuit and a driving method thereof. The power factor correction circuit refers to an inductor receiving an input voltage and supplying output power, a power switch connected to the inductor and controlling an inductor current flowing in the inductor, and an auxiliary coil coupled with the inductor with a predetermined turn ratio. The power factor correction circuit controls the output power by controlling a switching operation of the power switch, and counts the number of times that the inductor current reaches a predetermined maximum current to turn off the power switch when the count result reaches a predetermined short circuit threshold count.

Variable speed drive

Abstract: Systems and methods for improved Variable Speed Drives are provided. One embodiment relates to apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with Variable Speed Drives, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an Active Converter to the AC mains voltage during complete line dropout. Another embodiment relates to an Active Converter-based Variable Speed Drive system with Improved Full Speed Efficiency. Another embodiment relates to a liquid- or refrigerant-cooled inductor. The liquid- or refrigerant-cooled inductor may be used in any application where liquid or refrigerant cooling is available and a reduction in size and weight of a magnetic component is desired.

Broadband, Efficient, Electrically Small Metamaterial-Inspired Antennas Facilitated by Active Near-Field Resonant Parasitic Elements

Abstract: The possibility of using an active internal matching element in several types of metamaterial-inspired, electrically small antennas (ESAs) to overcome their inherent narrow bandwidths is demonstrated. Beginning with the Z antenna, which is frequency tunable through its internal lumped element inductor, a circuit model is developed to determine an internal matching network, i.e., a frequency dependent inductor, which leads to the desired enhanced bandwidth performance. An analytical relation between the resonant frequency and the inductor value is determined via curve fitting of the associated HFSS simulation results. With this inductance-frequency relation defining the inductor values, a broad bandwidth, electrically small Z antenna is established. This internal matching network paradigm is then confirmed by applying it to the electrically small stub and canopy antennas. An electrically small canopy antenna with k? = 0.0467 that has over a 10% bandwidth is finally demonstrated. The potential implementation of the required frequency dependent inductor is also explored with a well-defined active negative impedance converter circuit that reproduces the requisite inductance-frequency relations.

Predictive Current Controlled 5-kW Single-Phase Bidirectional Inverter With Wide Inductance Variation for DC-Microgrid Applications

Abstract: This paper presents design and implementation of a 5-kW single-phase bidirectional inverter with wide inductance variation. For dc-microgrid applications, the bidirectional inverter has to fulfill grid connection and rectification with power factor correction to regulate the dc bus to a certain range of voltages. In the inverter operation, inductor current can vary from 0 to 32 A in one line cycle. This will result in wide inductance variation, around seven times for an inductor constructed with a molybdenum permalloy powder core, and thus, high current ripple and fluctuation. In this paper, we take into account this variation while designing controller and selecting key components to ensure inverter normal operation. Additionally, to adopt a cost-effective microcontroller for the inverter, the sensitivities of the control to various parameters are investigated and presented in this paper. Experimental results measured from a 5-kW single-phase prototype have verified the feasibility of the designed inverter.

A comparative analysis of Switched-Capacitor and inductor-based DC-DC conversion technologies

Abstract: This paper compares the performance of Switched-Capacitor (SC) and inductor-based DC-DC conversion technologies. A metric to compare between the two topologies is discussed, and is used to compare switch utilization. Fundamental limits on utilization of reactive elements developed in the literature for all DC-DC converters are also reviewed and discussed, and this analysis shows that popular SC and inductor-based converters achieve the limits of utilization for reactive components. These limits are stated in terms of the ratio of output power to required stored energy in reactive elements. A detailed analysis of available surface mount discrete components and on-die devices reveals that capacitors have substantially higher energy and power density than their magnetic counterparts. The challenging regulation task for SC converters is also discussed, with a promising strategy outlined. The SC converter is evidently a promising candidate for future high power density integrated DC-DC converters.

Power Optimization of Vibration Energy Harvesters Utilizing Passive and Active Circuits

Abstract: This article presents the maximum power operating conditions for piezoelectric energy harvesters when connected to several different circuit topologies. Four circuits are studied herein for comparison: a simple resistive load, the standard rectifier circuit, and parallel and series synchronized switch harvesting on inductor. A single-mode model of a vibration-based energy harvester under base excitation is developed to capture the important dynamics near its fundamental resonance while providing a simple basis for performing design optimization. Relevant dimensionless parameters are given to provide a scale-free context for discussing the optimal operating points. For a prescribed vibration energy harvester, the base excitation frequency and load impedance for maximum power generation are provided by the results of this study. Furthermore, the effects of mechanical damping, electromechanical coupling, circuit quality factor, and rectifier forward voltage are presented. These effects are discussed in order to cite the salient parameters in the design of these energy harvesting systems.

An Improved Zero-Voltage Switching Inverter Using Two Coupled Magnetics in One Resonant Pole

Abstract: A novel soft-switching inverter using two small coupled magnetics in one resonant pole is proposed to ensure the main switches operating at zero-voltage switching from zero load to full load and the auxiliary switches at zero-current switching with load adaptability and small current stress. Since independent coupled magnetics structure avoids the unwanted magnetizing current freewheeling loop, the size of the coupled magnetics can be minimized with low magnetizing inductance, and the saturable inductor can be eliminated. Detailed circuit operation is described, and voltage-second balance condition of the magnetics is expressed mathematically. A 4-kW hardware prototype has been designed, fabricated, and tested to verify the validity of the novel circuit and the improved performance of the proposed soft-switching inverter. Experimental results show an excellent agreement with analytical results. Since the measured efficiency from 20% to 100% load consistently shows above 97.8% and peaks at 98.2%, the proposed inverter is very attractive for high-efficiency applications where energy saving is a major concern.

A family of zero current switching switched-capacitor dc-dc converters

Abstract: This paper presents a new zero current switching (ZCS) technique for a family of switched-capacitor dc-dc converters. Compared to the traditional ZCS switched-capacitor dc-dc converters by inserting a magnetic core in the circuit, these new ZCS switched-capacitor dc-dc converters employ the stray inductance present in the circuit as the resonant inductor and provide soft switching for the devices. These ZCS switched-capacitor dc-dc converters do not utilize any additional components to minimize switching loss and reduce the current and voltage spike, thus leading to high efficiency and reliable benefit over traditional switched-capacitor dc-dc converters. Moreover, the bulky capacitor bank existing in traditional switched-capacitor circuits for high power high current application to achieve high efficiency was reduced significantly. Small size, low capacitance, low ESR, high current rating and high temperature rating ceramic capacitors can be employed. Therefore, by using proposed ZCS technique, small size, high power density, high efficiency, high temperature rating, and high current rating switched-capacitor dc-dc converter could be built. Simulation and experimental results are given to demonstrate the validity and features of the soft switching switched-capacitor dc-dc converters.

A Resonant Gate-Drive Circuit Capable of High-Frequency and High-Efficiency Operation

Abstract: This paper deals with a new resonant gate-drive circuit for power MOSFETs. The proposed gate-drive circuit is characterized by a resonant inductor connected in series with the gate terminal of the driven MOSFET. The inductor and the input capacitance of the MOSFET form a series resonant circuit, which enables to charge or discharge the gate-to-source input capacitance of the MOSFET without any electric power consumption in theory. Experimental results are shown to verify the viability of the resonant gate-drive circuit. As a result, the proposed resonant gate-drive circuit reduces its power consumption by a factor of ten, compared with a conventional one. A 360-kHz and 1-kW MOSFET inverter driven by the proposed gate-drive circuits exhibits a high efficiency more than 99%, considering the losses in the two main MOSFETs and the two resonant gate-drive circuits.

Inductor winding loss owing to skin and proximity effects including harmonics in non-isolated pulse-width modulated dc-dc converters operating in continuous conduction mode

Abstract: A general expression for winding loss (copper loss) including harmonics for an inductor carrying periodic non-sinusoidal current is presented. The skin and proximity effects are taken into account. Expressions for amplitudes of inductor current harmonics are derived and illustrated as functions of duty cycle for selected non-isolated converters namely buck, boost and buck-boost converters. An example of inductor design procedure using the area-product method is shown for a buck converter operating in continuous conduction mode (CCM). The amplitude spectra of the inductor current, winding resistance and winding power loss are illustrated. Inductor winding losses in the designed inductor are analysed using MatLab simulations. Experimental results using the designed inductor are also presented.

Design and Analysis of Single-Stage Power Factor Correction Converter With a Feedback Winding

Abstract: A new single-stage power factor correction (SSPFC) converter is proposed for the adapter application, which is composed of a flyback converter, a feedback winding and a front-end input current shaper. Through the feedback winding, a direct energy transfer path is configured to improve the conversion efficiency and alleviate the voltage stress across the bulk capacitor. Moreover, the feedback winding is connected to the input through only two diodes, which results in low conduction losses. Equations and configurations are given to design the input current-shaping inductor and the magnetizing inductor of the transformer, which are operated in the discontinuous conduction mode (DCM) and the DCM/ continuous conduction mode boundary mode respectively for well-shaped current waveform and reduced bulk capacitor voltage. The theoretical analysis of the converter is verified by two SSPFC prototype circuits with 19 V/90 W output. One prototype achieves a high efficiency of 90.3%, while complying with IEC 61000-3-2 Class D standard. With a different turns ratio design, the power factor can be further improved to 0.97 in another prototype.

A Dual-Mode Single-Inductor Dual-Output Switching Converter With Small Ripple

Abstract: Single-inductor dual-output (SIDO) switching converters always suffer from large ripple and severe cross-regulation problem, when a large inductor current is switched between two outputs. This paper proposes a novel fly capacitor method for SIDO converters to reduce the output ripple and spike. An adaptive common-mode control is presented to suppress the cross-regulation problem. A duty-ratio-based current estimation method is proposed to detect the load current, and the converter can automatically switch between pulsewidth modulation and pulse-frequency modulation modes. The two outputs of the converter are specified for 1.2 V/400 mA and 1.8 V/200 mA with input voltage ranging from 2.7 to 5 V. The chip has been fabricated on a 0.25-? m CMOS mixed-signal process. The conversion efficiency is 82% at a total output power of 840 mW, while the output ripple is about 20 mV and spike is less than 40 mV. The maximum overshot voltage during load response is 50 mV.

LED lighting device and illumination apparatus

Abstract: The present invention provides a pair of input terminals to which AC voltage is input, the AC voltage being phase-controlled by a dimmer for phase-controlling AC voltage of an AC source; a damping circuit which has a resistor inserted to a position, into which input current flows from the AC source via the dimmer in series, and a capacitor and an inductor which form a closed circuit together with the AC source and the dimmer, and suppresses high-frequency vibration generated in the dimmer when a phase control element of the dimmer is turned on; and an LED lighting circuit which rectifies AC voltage phase-controlled and input via the pair of input terminals, converts DC output voltage, which is obtained by rectification, so that the voltage adapts to a load, and lights the LED.