Abstract: A rotor has rotor cores divided in the axial direction. A permanent magnet is mounted at the position of each of the magnetic poles of cores. The permanent magnet of each magnetic pole is configured by a single tabular member that penetrates the two divided cores in the axial direction. Convex parts are respectively provided on the outer peripheries of the respective magnetic poles of the rotor cores along the axial direction of the rotor. The convex parts are provided to positions that are displaced for each of the two divided cores. The magnetic flux density increases in the convex parts, which becomes the magnetic pole center. Since the convex parts positions are displaced to each other, a skew function can be exhibited even if the permanent magnet is mounted at the same position.

Abstract: A wound stator includes a plurality of windings, each winding including a primary lead and a secondary lead defined by free ends of the winding. Each of the windings being associated with a first, second or third phase. For each phase, a plurality of the primary leads are wrapped around a termination side of the stator to a common primary base lead to form a primary lead connection for the phase. For each phase, a plurality of the secondary leads are wrapped around the termination side of the stator to a common secondary base lead to form a secondary lead connection for the phase.

Abstract: A superconducting coil whose shape can be modified after it is shaped and a superconducting rotating machine with the superconducting coil are provided. The superconducting coil has an feature that the superconducting coil 1 comprising a superconducting material wire 5 coated with an insulation material and a coil frame 4 on which the superconducting material wire 5 is wound, the coil frame 4 comprising a first member 2 being a thin plate in a circular ring shape and a second member 3 jointed with an inner periphery portion of the first member 2, the first member inner periphery portion extending from the jointed portion toward an outer periphery of the first member, wherein the superconducting material wire 5 is wound between the first member 2 and the second member 3, which constitute the coil frame 4.

Abstract: A magnetic circuit structure, such as a motor, is provided with: a rotor having rotor-side magnetic poles formed on the outer surface; and a stator having stator-side magnetic poles formed on the inner surface. The magnetic circuit structure has an air gap between the outer surface of a rotor-side magnetic pole and the inner surface of a stator-side magnetic pole in the location where the rotor-side magnetic pole and the stator-side magnetic pole face each other. At least one pair of a protrusion and a recess is created so that the outer surface of a rotor-side magnetic pole and the inner surface of a stator-side magnetic pole face each other through the air gap in the direction of the actual line of the rotation axis, and each pair of a protrusion and a recess has two or three steps in the direction of the radius around the rotation axis.

Abstract: A stator for an electric rotating machine includes a stator core that has an annular yoke portion, a plurality of tooth portions, a plurality of connecting portions and a plurality of slots. The tooth portions are separately formed from and assembled to the yoke portion. Each of the tooth portions extends radially inward from a radially inner periphery of the yoke portion. The tooth portions are arranged in the circumferential direction of the yoke portion at predetermined intervals. Each of the connecting portions circumferentially extends to connect a corresponding circumferentially-adjacent pair of the tooth portions. Each of the slots is formed between a circumferentially-adjacent pair of the tooth portions. Moreover, each of the slots is partitioned by a corresponding one of the connecting portions into a radially-outer section and a radially-inner section.

Abstract: A radioisotope-powered energy source comprising: a flexible center substrate coated with the radioisotope, wherein the substrate comprises upper and lower surfaces; and two substantially identical sequences of layers bonded to each other and to the upper and lower surfaces via electrically insulating mesh barriers, wherein each sequence comprises the following layers bonded together in a y-direction in the following order: a first low-density alpha particle impact layer, a first high-density beta particle impact layer, a second low-density alpha particle impact layer, a second radioisotope-coated substrate, a third low-density alpha particle impact layer, a second high-density beta particle impact layer, and a photovoltaic layer.

Abstract: An electromechanical resonator including: at least one deformable element, and at least one electrode that simultaneously supplies, to the at least one deformable element, at least one first actuating force at a first frequency, and a second actuating force at a second frequency, the first and the second frequencies creating at least two simultaneous resonances with a primary resonance at a frequency ?0 equal to the first frequency and the second frequency being equal to a subharmonic resonant frequency (k?0, with k>1) of the resonator, or to a superharmonic resonant frequency (?0/k, with k>1).

Abstract: A vibration power generator includes a first substrate, a first electrode disposed on a lower surface of the first substrate and including a film retaining electric charges, a second substrate opposing the lower surface of the first substrate, a second electrode disposed on an upper surface of the second substrate, a third electrode disposed on the upper surface of the first substrate and including a film retaining the electric charges, a third substrate opposing the upper surface of the first substrate, and a fourth electrode disposed on a lower surface of the third substrate and opposing the third electrode. The film of the first electrode has a polarity different from a polarity of the film of the third electrode, and the vibration power generator includes a restoring force generation member giving a restoring force when an external force is not exerted to the first substrate.

Abstract: A power generation unit includes: a deformation member which is deformed by switching a deformation direction; a piezoelectric element which is installed to the deformation member; a pair of electrodes which are installed to the piezoelectric element; an inductor which is installed between the pair of the electrodes and which together with a capacitive component of the piezoelectric element constitutes a resonance circuit; a switch which is connected in series to the inductor; a full bridge rectifier which is installed between the pair of the electrodes to rectify an AC current generated by the piezoelectric element; a voltage detection circuit which detects potentials of an anode and cathode of a diode included in the full bridge rectifier; and a controller which allows the switch to be in an ON state for a predetermined time interval based on an output signal of the voltage detection circuit.

Abstract: A dynamic three-degree-of-freedom actuator/transducer element comprising at least three piezoceramic actuators and force sensors, as integrated stacks, which are preloaded in the housing by a low-stiffness tension bar, and are constrained, by means of a flexible shell, against shear force and torsion moment, whereby the element, when powered by external voltage source, is able to generate a dynamical axial force and displacement and dynamical bending and moment in the two principal tilt degrees of freedom around two orthogonal axes perpendicular to the principal displacement. When subjected to an axial force or a tilting moment, the transducer is able to generate charges that are proportional to the exerted force and moments.

Abstract: A solid state actuator arrangement comprising an actuator which is configured as a solid state bending actuator and which has a first and a second end section opposite each other, a fastening device for fastening the first end section of the actuator in such a manner that it can still be adjusted, and connections for applying a driver signal to the actuator for adjusting the second end section by bending the actuator between at least two positions, an extension element being fastened to the free second end section of the actuator.

Abstract: Disclosed is an apparatus used in an electronic device for providing haptic feedback. The apparatus includes a main board defining a mounting surface, a vibration unit mounted on the mounting surface of the main board, the vibration unit being capable of vibrating along a direction parallel to the mounting surface and defining at least two fastening portions at two distal ends thereof. At least two screws are provided to fix the vibration unit on the main board through the fastening portions along a direction perpendicular to the mounting surface.

Abstract: The present disclosure provides a manufacturing method of a quartz-crystal device, in which its lid and base is manufactured with smaller thermal expansion coefficient between AT-cut quartz-crystal wafer.

Abstract: The invention discloses a three dimensional LED arrangement and heat management method using a heat transfer or conduction pipe to enable rapid heat transfer from a three dimensional cluster of LEDs to a heatsink with or without active cooling, the light emitted from the three dimensional cluster not being obstructed by a heat sink arrangement such that the light beam profile generated by the light appears similar to that generated by traditional incandescent bulbs.

Abstract: An objective is to provide a spark plug in which a ground electrode has a protrusion formed from the same material as that used to form the ground electrode and the heat transfer performance of the protrusion is improved to thereby improve erosion resistance. A spark plug 1 includes a rodlike center electrode 5 extending in the direction of an axis CL1; a substantially cylindrical insulator 2 provided externally of the outer circumference of the center electrode 5; a substantially cylindrical metallic shell 3 provided externally of the outer circumference of the insulator 2; and a ground electrode 27 extending from a front end portion 26 of the metallic shell 3 and forming a spark discharge gap 35 between a distal end portion thereof and a front end portion of the center electrode 5.

Abstract: A spark plug that prevents a sharp increase in resistance of a resistor and materializes an excellent load life performance. The spark plug has a resistor formed by heat-sealing of a resistor composition that contains, at least, a conductive material and glass powder. The glass powder contains between 35.0 mol % and 69.8 mol % SiO2, between 15.0 mol % and 49.8 mol % B2O3, between 5.0 mol % and 20.0 mol % Li2O, and at least one additive selected from MgO, CaO, SrO, BaO, Na2O, K2O, ZnO, and ZrO2 in a total of between 2.6 mol % and 25.0 mol %. Further, the total content of Li2O and the additive(s) in the glass powder is between 15.2 mol % and 45.0 mol %, and the ratio of the Li2O content to the total content of the additive(s) is between 1.3 and 5.0.

Abstract: A spark plug includes a ground electrode. The cross sectional area S of a ground electrode base member of the ground electrode satisfies a relation 1.8 mm2?S?3.2 mm2. The embedment depth A of a noble metal tip embedded in a second base member surface and the tip thickness B of the noble metal tip measured along the direction in which the noble metal tip is embedded in the second base member surface satisfy a relation 0.4?(A/B)?0.8.

Abstract: A high intensity discharge lighting assembly capable of instant ON/OFF operation with a lamp housing having therein an HID lamp, an instant ON igniter circuit and lamp driver circuitry. The housing may have a screw in base or may be configured for fixed mounting on an open receptacle box. In one version, a non-replaceable HID lamp has leads permanently connected to the instant ON circuitry. In another version, the HID lamp has an integral base with pins which are plugged in to a socket provided in the housing.

Abstract: A photoluminescent device includes a substantially cylindrical housing having an optically transparent upper surface, the housing defining an interior cavity, a phosphorescent material being disposed within the interior cavity proximate the optically transparent upper surface, whereby the housing of the device has an elongate body portion configured for insertion into a bore or hole in a substrate with the optically transparent upper surface positioned proximate to the surface of the substrate.

Abstract: The present invention relates to an organic light emitting device and a manufacturing method thereof. The present invention discloses an organic light emitting device including: a plurality of scanning signal lines; a first and second contact assistant; a plurality of data lines crossing the scanning signal lines; a driving voltage line; and a first pixel, a second pixel, and a third pixel alternately arranged, wherein each pixel includes: a switching transistor, a driving transistor including an output terminal, a pixel electrode connected to the output terminal, the pixel electrode including at least two layers including a transflective electrode, an organic light emitting member arranged on the pixel electrode, and a common electrode arranged on the organic light emitting member, wherein the first pixel further includes a supplementary member arranged on the pixel electrode, and wherein the first and second contact assistants include the same material as the supplementary member.

Abstract: A light emitting element according to the invention comprises a plurality of layers which is interposed between a pair of electrodes, in which at least one of the plurality of layers is formed of a layer containing a light emitting material, and the layer containing a light emitting material is interposed between a layer containing an oxide semiconductor and/or metal oxide and a material having a higher hole transporting property than an electron transporting property, and a layer containing an oxide semiconductor and/or metal oxide, a material having a higher electron transporting property than a hole transporting property and a material which can donate electrons to the material having a higher electron transporting property than a hole transporting property.

Abstract: It is an object of the present invention to provide a metal halide lamp in which arc discharge in the initial stage of lamp lighting can be stabilized. A metal halide lamp includes a translucent outer tube with a base formed at one end thereof and a light-emitting portion disposed in the outer tube. This metal halide lamp is configured as a vertical mounting type such that the base thereof looks toward the upper side. The discharge tube has mercury and metal halides enclosed therein. Assuming that a lamp rated power is P [W], then a mercury concentration d(Hg) [?mol/cm3] in the discharge tube falls within a range of values of ±10% of a mercury concentration d(Hg) obtained by the following equation “d(Hg)=0.0007P2?0.4113P+99.557”.

Abstract: A lamp includes a discharge vessel with electrodes extending into the discharge vessel and an ionizable fill scaled within the vessel. The fill includes a buffer gas, optionally mercury, and a halide component. The lamp includes available oxygen, sealed within the discharge vessel, at a concentration of at least 0.1 ?mol O/cc.

Abstract: The LED lamp tube includes a tube, an LED module, a power supply and a terminal connector. The LED module is accommodated in the tube. The power supply is electrically connected to the LED module and includes a first heating element at one side of the LED module. The terminal connector is electrically connected to the power supply and mechanically connected at one end of the tube.

Abstract: A light emitting device comprises: an LED; a LED holder having a LED mount, a radiation fin provided on a back side or a periphery of the LED mount, and an engaging part projecting from a center of the back side of the LED mount; a power circuit supplying drive power to the LED; and a body having an inner space for accommodating the power circuit, one end, and the other end where the LED holder is fixed, wherein the other end of the body has an engaged part engaged to the engaging part of the LED holder, and holding the LED mount and the radiation fin in a state of separation from the body; heat conductivity of the LED mount and the radiation fin is higher than that of the engaged part of the body.

Abstract: The disclosure provides a backlight module applied to a liquid crystal display device. The backlight module includes: a control circuit for outputting a driving signal according to an analog adjustment signal or a digital adjustment signal; a driving circuit for outputting a lamp voltage according to the driving signal; a fluorescent lamp set, including a plurality of lamps, for receiving the lamp voltage and thereby generating a lamp current; a lamp feedback circuit c for outputting a feedback signal according to the lamp voltage; and a dynamic protection circuit, for dynamically adjusting a protection command signal according to the analog dimming signal or the digital dimming signal, comparing the protection command signal and the feedback signal and thereby outputting a comparing result signal to the control circuit.

Abstract: Multiple output channel light source power supply circuits, and methods for protecting the output channels, are provided. A front end circuit receivess an input voltage and provides a regulated front end DC voltage. A plurality of voltage converter circuits are each configured to receive the regulated front end DC voltage and provide a separate associated DC output for an associated one of the multiple output channels. A protection switch is coupled therebetween, and includes a conducting state, to couple the front end DC voltage to the plurality of voltage converter circuits, and a non-conducting state, to decouple the front end DC voltage. A current sense circuit is coupled to the voltage converter circuits, and provides a current sense output representative of current through at least one voltage converter circuit. A controller circuit places the protection switch in the non-conducting state in response to the current sense output.

Abstract: A semiconductor lighting device has an array of semiconductor light sources arranged in an x-y grid, a power input in electrical connection with the array and arranged to provide power to the light sources, a microcontroller in electrical connection with the array arranged to alter operation of the array as necessary, and a connector in electrical connection with the microcontroller, arranged to provide an interface to the microcontroller. The semiconductor lighting device has a first interface to allow a first level of access to the microcontroller by an end user, a second interface to allow a second level of access to the microcontroller for maintenance operations, and a third interface to allow a third level of access to the microcontroller during production.

Abstract: The present invention provides a backlight module, and the backlight module has an LED module which has a plurality of light emitting diodes averagely divided into a plurality of light strings. Forward voltages of the light emitting diodes are between a minimum forward-voltage value and a maximum forward-voltage value, and each of the light strings at least has one first light emitting diode and one second light emitting diode. The first light emitting diode has the minimum forward-voltage value and the second light emitting diode has the maximum forward-voltage value. The backlight module is contributive to lower power loss on a constant current control circuit.

Abstract: An improved control circuit arrangement and control method is described for supplying power to, and for controlling, light-emitting diodes used for illuminating. The control circuit arrangement includes a driver circuit capable of operating in multiple modes for providing an operating current for operating at least one light-emitting diode, wherein the operating current has different positive intensities. In particular, the present control circuit arrangement and control method now deliberately exploit the fact that the color spectrum of a light emitting diode is dependent on the intensity or current with which it is operated, and improves the color rendering index by deliberately operating the light emitting diodes with different intensities over time.

Abstract: A switch device controls a voltage applied to a load element according to an electric power supply from a power source. A driver circuit controls activation and deactivation of the switch device. A circuit portion sets a duty ratio and output the duty ratio to the driver circuit for causing the driver circuit to activate the switch device according to the duty ratio to control a voltage applied to the load element. The circuit portion sets the duty ratio according to a duty ratio characteristic curve. In the duty ratio characteristic curve, the duty ratio decreases gradually with increase in a voltage of the power source, and decrease in the duty ratio with increase in the voltage of the power source becomes small gradually.

Abstract: A capacitive touch sensor and LED driver device achieves a reduction in pin count by multiplexing LED drive functionality and capacitive sense functionality on each input/output pin. A control circuit switches between LED drive mode and capacitive sense mode at a frequency of approximately 200 Hz, although other switching frequencies can be used. A bias driver functions as a current sink for LEDs in LED drive mode and can also be used to drive a bias voltage to the LEDs during capacitive sense mode to improve noise immunity.

Abstract: A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.

Abstract: According to one embodiment, a switching power supply device includes a direct-current power supply and a switching operation conversion circuit. The switching operation conversion circuit is connected to the direct-current power supply, and includes an inductor, a switching element, a diode, a gate drive circuit, an input end and an output end. The switching element allows an increasing current to flow to the inductor from the direct-current power supply at an on time of the switching element. The diode allows a decreasing current to flow to the inductor at an off time of the switching element. The gate drive circuit controls a gate voltage of the switching element to turns off the switching element when the increasing current reaches a saturated state relative to a source-drain voltage of the switching element. The input end is connected to the direct-current power supply. The output end is connected with a load.

Abstract: A driving circuit for a LCD backlight source comprising a BOOST structure which comprises a capacitor C12, a capacitor C13, an inductor L2, a diode D2, and a MOSFET, wherein the driving circuit further comprises a capacitor C11, a capacitor C14, a diode D3, and a diode D4. One terminal of the diode D3 is connected to one terminal of the capacitor C13, and the other terminal is connected to one terminal of the diode D4; the other terminal of the diode D4 is connected to one terminal of the capacitor C14 which is the output terminal of the circuit, and the other terminal of the capacitor C14 is grounded; one terminal of the capacitor C11 is connected between the inductor L2 and the diode D2, and the other terminal of the capacitor C11 is connected between the diode D3 and the diode D4.

Abstract: An apparatus and method for controlling the brightness and luminance of a light, such as an LED. The embodiment may vary the brightness and luminance of the LED in a variety of ways to achieve a variety of effects. The exemplary embodiment may vary the rate at which the LED's luminance changes, such that an observer perceives the change in the LED's brightness to be smooth and linear as a function of time, regardless of the ambient light level. Changes to the LED's luminance may be time-constrained and/or constrained by a maximum or minimum rate of change.

Abstract: A fluorescent lamp starter unit determines whether the lighting fixture into which it has been plugged is in a first or second state. The lamp is on in the first state and off in the second state. If the fixture is in the first state then the starter unit uses a first method to detect ballast type, whereas if the fixture is in the second state then the starter unit uses a second method to detect ballast type. In one example, the first method involves turning on the power switch of the starter unit at a time after a zero-crossing and then using the periodicity of a transient switch current signal to determine ballast type, whereas the second method involves turning on the power switch at the time of the zero-crossing and then using peak amplitude information of the transient switch current to determine ballast type.

Abstract: A light emitting device includes a plurality of light emitting modules and a plurality of voltage controlling circuits capable of being independently controlled. Each voltage controlling circuit includes a dynamic voltage controlling module, a current controlling module, and a luminance controlling module. The dynamic voltage controlling module is used for comparing a voltage level at a second terminal of the light emitting module and a voltage level of a reference voltage source, so as to output a first voltage. The current controlling module is used for adjusting a bias current flowing through the light emitting module, according to the first voltage. The luminance controlling module is used for comparing the first voltage with a clock signal, and for generating a pulse width modulation signal according to a result of the comparison, so as to dynamically control a duty cycle of the light emitting module.

Abstract: Solid-State lighting devices and fixtures are presented in which capacitor plates are formed in the fixture and in the lighting device to form AC coupling capacitors with one or more intervening dielectrics when the lighting device is placed in the fixture to power a driver circuit of the lighting device while providing a fixture with no exposed live wiring.

Abstract: Disclosed herein is a light emitting diode (LED) driving device for driving a multi-channel LED element or an LED array for each channel, the LED driving device including: a constant current driver driving currents flowing in each channel; and a minimum voltage selector receiving voltage levels of each channel and selecting a minimum voltage level to thereby feedback the selected minimum voltage level to the constant current driver, wherein matching characteristics of currents flowing in each channel is improved and a size of an integrated circuit (IC) chip is also reduced as compared to a case according to the related art, thereby making it possible to reduce a production cost and satisfy the trend of miniaturization of the chip, while solving a performance deterioration problem due to deterioration of the matching of the currents between the channels.

Abstract: A method of controlling an electronic ballast for a lighting circuit, the ballast including a bleeder, for use with dimmer circuits, by, in response to a mains supply being connected to the lighting circuit, determining whether a dimmer circuit is present in the lighting circuit; and in response to determining a dimmer circuit is not present, disconnecting the bleeder from the lighting circuit at least until the mains supply is disconnected. The method may be used during start, and the determination of whether a dimmer circuit is present is stored at least until the mains supply is disconnected. Determination of either a leading or trailing edge phase cut dimmer may be made by looking for deviation from the expected sine-wave voltage, either directly through temporal or voltage deviation, or indirectly by examining the second differential of the voltage with respect to time.

Abstract: An LED drive circuit is provided that can be connected to an alternating current power source via a phase-control light controller and drives an LED load.

Abstract: An LED driving apparatus for suppressing harmonic components is provided. First and fourth portions 21 and 24 are in parallel to the first and second LEDs 11 and 12, respectively. The first portion 21 controls the current amount in said first LED 11. The fourth portion 24 controls the current amount in said first and second LEDs 11 and 12. The first and fourth controllers 31 and 34 control the first and fourth portions 21, respectively. A current detector 4 detects a signal based on the amount of a current flowing from the first and second LEDs 11 and 12. A signal providing portion 6 provides a voltage based on a rectified voltage provided from a rectifying circuit 2. The first and fourth controllers 31 and 34 compare the current detection signal with the signal voltage, and control the first and fourth portions 21 and 24 based on the comparison.

Abstract: A projection-type image display apparatus includes a high pressure discharge lamp, which utilizes the halogen cycle, and a lamp lighting apparatus that controls lighting of the high pressure discharge lamp. The lamp lighting apparatus performs lamp refresh processing to improve a lamp property. The lamp refresh processing involves performing low power lighting of the high pressure discharge lamp by changing the lighting power of the high pressure discharge lamp to a value that is lower than the rated power, and thereafter performing high power lighting of the high pressure discharge lamp by changing the lighting power to a value that is higher than the lighting power during the low power lighting.

Abstract: A current driving circuit may include a reference voltage input terminal; a resistor connection terminal; an output terminal via which the light emitting element is connected; a reference voltage generating unit; a transistor arranged such that one terminal thereof is connected to the resistor connection terminal; and an operational amplifier including first and second non-inverting input terminals and a single inverting input terminal, and arranged such that the output terminal thereof is connected to a control terminal of the transistor, the internal reference voltage is input to the first non-inverting input terminal, the external reference voltage is input to the second non-inverting input terminal, and the inverting input terminal thereof is connected to the resistor connection terminal. When the external resistor is connected between the resistor connection terminal and a ground terminal, a driving current is output via the output terminal.

Abstract: A control circuit selects a first control mode in which a switching element is turned on/off so as to flow current in an inductor in a continuous mode by which the current flows in the inductor without a sleep period, thereby fully lighting a light source load. The control circuit selects one of a second control mode in which a turn-on time of the switching element is changed and a third control mode in which an oscillating frequency is changed according to an interval, to which the designated dimming ratio corresponds, to light the light source load. An output capacitor connected between output terminals of a step-down chopper circuit smoothes a pulsation component of an output current supplied to the light source load and has capacity set so that a ripple ratio of the output current is less than 0.5 at the full lighting of the light source load.

Abstract: Electronic circuits provide an error signal to control a regulated output voltage signal generated by a controllable DC-DC converter for driving one or more series connected strings of light emitting diodes.

Abstract: A DC-DC converter for driving one or more LED (38), which converter comprises an integrated circuit (12) having a switch mode power circuit (24) and a 5 temperature sensing circuit (40) for providing an output indicating a temperature of said integrated circuit (12), the arrangement being such that, in use, said integrated circuit consumes power, some of which power is dissipated in said integrated circuit as heat causing a rise in said internal temperature, and wherein a change in said output from said temperature sensing circuit (40) is used by said integrated circuit to 10 adjust said consumed power whereby said internal temperature may be controlled.

Abstract: In a circuit (1) for sensing a property of light there are provided a first circuit element (7) that is sensitive to light and that is realized to generate an output signal (I1) during a measurement time period (?tM), wherein the output signal (I1) is generated according to light to which the first circuit element (7) is exposed and the temperature (T) of the first circuit element (7), and a second circuit element (8) that is realized to increase the temperature (T) of the first circuit element (7) during a warming time period (?tW) that precedes the measurement time period (?tM).

Abstract: Ballasts and LED drivers are presented for powering at least one light source, in which a shunt circuit provides a high impedance to allow operation of the light source when the AC input power exceeds a power threshold value, and provides a low impedance when the AC input power is below the power threshold value to prevent an output power stage from providing power to the light source.