Abstract: An apparatus for a mobile light source is described. The apparatus comprising: a first outer casing housing an array of lights, wherein the array of lights are located on a surface of a substrate, a second outer casing coupled with the first outer casing to create an enclosure that is substantially water tight, a heat shield composed of a metal alloy creating two compartments in the enclosure such that the array of lights is situated in a first compartment, and a printed circuit board (PCB) with circuitry for controlling the array of lights, the PCB situated in the second compartment of the enclosure housed by the second outer casing, and wherein a surface the PCB is substantially parallel to the surface of the substrate.

Abstract: An ultraviolet court-illumination system is used to light a playing court and any related equipment in a fluorescent manner. The system includes at least one playing court, a first plurality of ultraviolet (UV) court lights, a plurality of fluorescent game boundary-markers, and at least one fluorescent game fixture. The playing court is used for playing games or sports. The plurality of fluorescent game boundary-markers is superimposed onto the playing court and is used to delineate the boundaries of the playing court. The fluorescent game fixture is mounted onto the playing court and may be a net, a goal, or any other fixture used to play the sport. Each of the first plurality of UV court lights is peripherally positioned about the playing court and is used to illuminate the fluorescent game boundary-markers and the fluorescent game fixture. The first plurality of UV court lights is powered by a power source.

Abstract: Various embodiment may relate to a lighting device, including a light mixing element having a light entry surface and a light exit surface, multiple light sources, the primary light of which can be is radiated onto the light entry surface, a wavelength conversion unit having a carrier, on which a luminescent volume is arranged, which luminescent volume can be is illuminated by means of the primary light emitted by the light exit surface, and at least one decoupling optical unit for forming useful light emitted by the wavelength conversion unit, which has at least one non-imaging safety region. The multiple light sources radiate the primary light thereof at an angle onto the light entry surface. The at least one safety region occupies a position on the decoupling optical unit which corresponds to a region of high intensity of the primary light in the case of remote luminescent volume.

Abstract: A ventilation apparatus of a lamp module for vehicles may include: a lamp housing; a lamp emitting light through a light transmitting part; a light transmitting lens covering an opening of the lamp housing; an intake hole part formed through the lamp housing, and arranged at one side of the lamp; an exhaust hole part formed through the lamp housing, and arranged at the other side of the lamp; and an exhaust pipe having one side coupled to the lamp housing and connected to the exhaust hole part and the other side connected to an intake part of an engine.

Abstract: A headlamp, notably for a motor vehicle, comprising several light modules and an air cooling duct for the light modules with at least one air inlet for one or more fans, several air outlets to the light modules, and a passage connecting the one or more inlets with the outlets. The duct comprises at least one attached separating wall of the passage.

Abstract: A ventilation apparatus of a lamp module for vehicles may include a lamp housing, a lamp installed in the lamp housing and emitting light through a light transmitting part, a light transmitting lens covering an opening of the lamp housing and transmitting the light emitted from the light transmitting part, an intake hole part formed through the lamp housing and arranged at one side of the lamp, an exhaust hole part formed through the lamp housing and arranged at the other side of the lamp, an exhaust pipe coupled to the lamp housing and connected to the exhaust hole part, and an exhaust pump connected to the exhaust pipe and forcibly discharging the air between the lamp housing and the light transmitting lens through the exhaust pipe.

Abstract: A novelty lamp arrangement in which there is provided a light transmitting body member with a light emitting de ice therein and wherein the body member is the form of a hog's head or sow's head and the emitted light appears to be emanating from the body member.

Abstract: An apparatus containing light generating devices, such as LEDs, mounted in two opposing rows along the interior sides of an illumination area within the apparatus is provided herein. Light emitted from the devices are reflected out the front of the apparatus by a plurality of reflective pockets located in front of each device. The reflective pockets are aligned in two rows, each row of reflective pockets facing a row of light generating devices. The pockets are mounted at a generally 45-degree angle to the devices and to the front of the apparatus. The pockets cause the light emitted from each device to be reflected by approximately 90-degrees so that it exits the apparatus and illuminates an area roughly in front of the apparatus.

Abstract: A reflective sheet is provided, comprising a base layer, a reflecting layer coated on the base layer, and a scattering layer coated on a side of the reflecting layer that faces away from the base layer. Emergent light from such a reflective sheet is more uniform, whereby quality of an image displayed on a display device using said reflective sheet is improved.

Abstract: A light-emitting device includes: a light emitting element; and a light flux controlling member configured to allow incidence of light from the light emitting element and emit light incident on the light flux controlling member. The light flux controlling member includes an incidence region and an emission region. The incidence region includes a fresnel lens part having a plurality of projected lines formed to surround a central axis of the light flux controlling member. The projected line includes an incidence surface configured to allow incidence of the light from the light emitting element, and a reflecting surface paired with the incidence surface and configured to reflect the light incident on the incidence surface toward the emission region. An angle between the incidence surface and a line parallel to the central axis is greater than an angle between the reflecting surface and a line parallel to the central axis.

Abstract: An optical assembly for an LED light system with a LED light source is provided to control a light pattern of a light beam produced by the system, such as for spot or narrow flood light applications. The optical assembly includes a conical reflector with an interior reflective surface, a light diffuser and an optic holder. The light diffuser has an annular disk-shape with a central opening. The optic holder is mounted to a narrow open top of the reflector, and suspends the light diffuser inside of the reflector along an optical axis. The light diffuser is a cost-efficient optical element, which can be used in combination with the reflector to redistribute light in the system in order to soften a peripheral light area surrounding a center beam light area of the light pattern of the light beam, and reduce a harsh edge between the center beam and peripheral light areas.

Abstract: An illumination apparatus comprises a plurality of LEDs aligned to an array of directional optical elements wherein the LEDs are substantially at the input aperture of respective optical elements. An electrode array is formed on the array of optical elements to provide at least a first electrical connection to the array of LED elements. Advantageously such an arrangement provides low cost and high efficiency from the directional LED array.

Abstract: Beam forming optics having non-circular peripheral shapes are disclosed. The polygonal periphery of the disclosed beam forming optics interrupt surfaces of rotation used to define reflecting surfaces that collimate wide angle light emitted from an LED. The periphery of the lens handling narrow angle light is modified to permit light to fill the non-circular reflecting surface. The illustrated beam forming optics are configured to ensure that light emitted from the LED is handled only by surfaces configured to form the desired collimated beam.

Abstract: There is provided a lighting device (100) comprising a first tubular body (120), a second tubular body (130) within the first tubular body (120), and a support structure within the first tubular body (120). The support structure supports a plurality of Solid State Lighting (SSL) elements (160) on a support surface, said SSL elements being arranged to emit light under a range of angles including a first range. The support structure is fixed within the first tubular body (120) by the first tubular body (120) and the second tubular body (130). The support structure comprises a tube receiving member (156) extending from the support surface, said tube receiving member engaging with the second tubular body (130).

Abstract: The present utility model discloses a novel rotating lantern, including: a lampshade, where the top of the lampshade is provided with an upper cover, the top of the upper cover is provided with a lamp top, and the bottom of the lampshade is provided with a bottom cover; and an illumination unit, where the illumination unit is disposed on the top of the interior of the upper cover; the illumination unit includes a rotating motor, a rotating shaft, a light emitting diode (LED) luminaire, and a rotating cover; the rotating motor is embedded in the interior of the upper cover; the top of the rotating shaft is connected to an output end of the rotating motor; the rotating cover shaped like a bowl is connected to the bottom of the rotating shaft; the LED luminaire is annularly embedded in the interior of bowl-shaped space fanned by the rotating cover; and a bowl-shaped inner wall of the rotating cover is a transparent refractor.

Abstract: A rechargeable and waterproofing USB luminous ring that is cuttable and extendable includes a tube, an LED seat, a hard shell having a USB receptacle, and plural LEDs. Inside the tube is a string of LEDs connecting to an electric wire. The LED seat, protected by the hard shell, is sheathed by two ends of the tube and is a circuit board. The circuit connecting to the circuit board outside the LEDs is a parallel circuit, two ends of the hard shell include respectively two waterproofing ribs, an end of the hard shell is a switching button and a USB socket, and the other end of the hard shell contains two shields.

Abstract: The present invention relates to technology to implement a technique of managing light intensity by each wavelength band for a light apparatus at a low price, whereby the light intensity is suitable for plant growth. In the present invention, cheaper LED blue-chips are incorporated instead of more expensive LED red-chips which are conventionally incorporated in plant factories, which let the production cost of lighting apparatus for plant factories reduced. By applying red-series, green-series and yellow-series phosphors onto the LED blue-chips, light intensity by wavelength band of lighting apparatuses may meet target conditions which are favorable to plant growth. Further, work environment may be improved by reducing eyestrain due to red light-source, and growth efficiency of plants may be enhanced by improving wavelength characteristics of lighting apparatuses.

Abstract: An arrangement for forming an elongate, channel-type accommodation space comprises at least two elongate mounting rail elements, two of the mounting rail elements being arranged so that their front faces abut via a joint. The arrangement further comprises a first shaped part and a second shaped part connected to the first profiled part to form the channel-type accommodation space, said space at least substantially extending at least over the length of the two mounting rail elements, and one of the two shaped parts being fastened to the mounting rail elements.

Abstract: The present invention provides a tensile resistant light string comprising: multiple illuminating units electrically connected by multiple wires, wherein each one of the wires comprising: a tensile resistant layer; a conductive layer wrapping the tensile resistant layer, and an insulating layer wrapping the conductive layer; and wherein the insulating layer is made of cotton fiber, the conductive layer is consisting of multiple metal lines, the metal lines are made of copper, the tensile resistant layer is consisting of at least one line. The tensile resistance of the wires is enhanced by the tensile resistant layer.

Abstract: A wavelength converting device includes a heat dissipating member, a wavelength converting member, and a connecting member. The wavelength converting member is disposed on the heat dissipating member and contains a fluorescent material and a holding body including aluminum oxide, magnesium oxide, zirconium oxide, lutetium oxide, titanium oxide, chromium oxide, tungsten oxide, divanadium pentoxide, molybdenum trioxide, sodium oxide, yttrium oxide, silicon dioxide, boron oxide, or diphosphorus pentoxide. The connecting member contains a metal material and connecting the heat dissipating member and the wavelength converting member. The wavelength converting member includes an upper surface, side surfaces, and a lower surface. The connecting member is thermally connected to the side surfaces and the lower surface of the wavelength converting member.

Abstract: A lighting device (100, 300) comprising a housing (101, 301) comprising a polymer material, the housing including an elongated hollow neck portion (102) and a collar portion (104) arranged at an end of the neck portion. The collar portion includes an essentially annular surface (114, 414) surrounding the end of the neck portion peripherally. The collar portion has a metalized surface. The surface is structured into a plurality of electrically conductive pads (118, 318, 418) and the pads are electrically isolated from each other. A plurality of light emitting elements (120, 320, 420) are arranged on the collar portion of the housing. Each of the light emitting elements has a first terminal (128) electrically connected to a first electrically conductive pad (118a, 418a) and a second terminal (124) electrically connected to a second electrically conductive pad (118b, 418b). The collar portion is directly in contact with the surroundings, promoting an improved heat transfer from the light emitting elements.

Abstract: Disclosed herein are a display device, a display system and method thereof. The display device includes a display panel, a light emitter configured to emit light to display an image on the display panel, a pipe positioned adjacent to the light emitter and having a conductive fluid and a gas therein, and electrodes provided in the pipe and polarized, where heat is generated to move the conductive fluid inside the pipe when the light emitter emits light, and electricity is generated while moving and passing around the electrodes.

Abstract: A light emitting diode (LED) module includes a first end cap, a second end cap and a reflector portion. The reflector portion extends longitudinally between the first end cap and the second end cap. The reflector portion includes a coolant passageway defined longitudinally through the reflector portion and is fluidically coupled to the first end cap and the second end cap. An LED package is disposed adjacent to the reflector portion. An orifice bushing can be disposed within a coolant passage defined in the first end cap to restrict coolant flow through the reflector portion to preclude starvation of coolant flow elsewhere in the LED module.

Abstract: A lighting device includes: a substrate that is light transmissive and has one or more region in which a phosphor layer is formed; a heat transfer plate having a first surface in surface-to-surface contact with a surface of the substrate and having one or more apertures overlapping the one or more regions; and a heat dissipation plate having a surface in surface-to-surface contact with a second surface of the heat transfer plate opposite the first surface and having an aperture overlapping the one or more apertures.

Abstract: A luminaire including a housing made of thermally conductive material having a top, a bottom and two opposite sides connecting the top to the bottom, each side having plurality of external, vertically spaced, substantially parallel cooling fins that extend longitudinally and project laterally outwardly of the housing, preferably at a shallow downward and outward angle. The housing configuration provides a large surface area per unit of housing length to optimize heat dissipation. A configurable, cartridge-like LED bezel assembly—readily replaceable in the field—is supported on the bottom of the housing. A driver for the LED assembly—also readily replaceable in the field—is located within the housing.

Abstract: A candle wick trimming device including a cutting assembly having first and second elongated members that are pivotably coupled together. A distal portion of the first elongated member has a cavity defined by a floor and a plurality of sidewalls extending upwardly therefrom. One of the sidewalls defining the cavity forms a first cutting edge. A distal portion of the second elongated member closes the cavity when the cutting assembly is in a closed state. The second elongated member also has a second cutting edge at its distal-most end. The first and second cutting edges interact to shear a candle wick to a desired length and force the sheared portion of the candle wick into the cavity.

Abstract: The present inventions provide, among other things, tapered burner tubes having raised gas ports and a smooth interior surface free from obstructions. Venturi members and air shutters may also be included.

Abstract: The present invention relates to a combustion device 100 for burning refractory hazardous gases and a burning method for the combustion device. More particularly, the combustion device 110 for burning refractory hazardous gases, which is provided in a scrubber system 1 for burning waste gases, the combustion device 110 includes: a first porous body 141; a second porous body 142; and an igniter for forming a flame surface 143 at the interior of the combustion device 110, wherein the flame surface 143 formed by the igniter is located between the first porous body 141 and the second porous body 142, and so as to form the flame surface 143, at least one of the first porous body 141 and the second porous body 142 is moved to conduct excess enthalpy combustion.

Abstract: A gas flow controller for use in a gas-fired apparatus including a pilot burner and a main burner is provided. The controller includes a housing defining a diaphragm chamber, a pilot valve operable to open and close a first fluid flow path between a gas supply inlet of the gas flow controller and the diaphragm chamber, and a main burner valve operable to open and close a second fluid flow path between the gas supply inlet and the main burner. The main burner valve includes a diaphragm that is disposed within the diaphragm chamber and includes a central portion and an annular outer portion. The outer portion is configured to deflect into engagement with the housing to close a third fluid flow path in response to an over-pressure condition at the gas supply inlet.

Abstract: A burner control valve with speed control includes a speed control assembly for metering loading pressure into a loading pressure chamber to prevent pilot light blow out and/or backfire in a downstream burner.

Abstract: A portable exothermic welding ignition controller includes a housing configured to receive a first portion of a portable power tool battery with a second portion of the portable tool battery external to the housing. A circuit board is positioned within the housing and configured for electrical coupling to the portable power tool battery. An actuator is operatively engageable with the circuit board for selectively discharging power from the portable power tool battery to a connection terminal electrically coupled to the circuit board.

Abstract: The present disclosure relates to a fuel-air premixer for a turbine system. The fuel-air premixer includes a swirler and a centerbody. The swirler is configured to direct a flow of air through the premixer, and the centerbody is configured to inject fuel into the flow of air. Additionally, the centerbody includes an airfoil shape that reduces and/or substantially eliminates recirculation pockets to prevent autoignition and/or flame holding in a combustion chamber. Accordingly, the turbine system may produce fewer NOx emissions.

Abstract: A gas turbine assembly and method for operating the gas turbine assembly are provided. The method for operating the gas turbine assembly may include compressing a process fluid containing inlet air through a compressor to produce compressed inlet air, combining fuel from a main fuel source with the process fluid, and preheating the process fluid containing the inlet air and the fuel in a warmer disposed downstream from the compressor. The method may also include heating an oxidizer by flowing the preheated process fluid from the warmer to the oxidizer, and oxidizing the process fluid containing the compressed inlet air and the fuel in the oxidizer to produce an oxidation product. The method may further include expanding the oxidation product in a turbine to generate rotational energy, and preventing the process fluid from flowing upstream to the compressor with a check valve.

Abstract: A cooking device may be for a solid-fuel cooker that may include a firebox for carrying solid-fuel therein and having a base and a sidewall extending upwardly from the base, and a cooking plate defining a first cooking surface. The cooking device may include a tubular fuel container for carrying the solid-fuel therein, and to be carried within the firebox and spaced inwardly from the sidewall. The tubular fuel container may have upper and lower open ends. A solid cover may be carried by the upper open end and may include a cover base having opposing first and second surfaces. The first surface may define a second cooking surface, which may be coupled to the upper open end to define an air seal therewith. A cover sidewall may extend upwardly from the first surface to carry the cooking plate in spaced relation from the cover base.

Abstract: The present invention comprises an assy PH base at the bottom, a gas combination valve, a reducing bushing unit, a PH perforated cylinder, a tubing unit along with the pilot assembly, PH pan head, a gas combination control assembly, a gas liter unit, a burner assembly and an assy PH emitter grid assembly. A reflector is mounted at the top of the assy PH emitter grid assembly. The present invention provides an automatic ignition system along with ON/OFF switch and the device also has an inbuilt transformer which provides the safety to the user(s). Hence, the present invention is very easy to operate and user friendly.

Abstract: Devices and methods for reflecting at least a portion of the heat output of a space heater are described. A supplementary reflector is positioned to reflect a portion of the heat generated by the space heater. The supplementary reflector can be angled relative to the vertical axis to direct reflected heat downwards, while also providing adjustable side panels that provide focus and further direction of the reflected heat.

Abstract: A manifold has a frame and a plurality of valves supported by the frame, each valve having a cross gear. The manifold also has a screw drive and a splined rotatable shaft parallel to the screw drive. The manifold further includes a slider driven by the screw drive over the splined rotatable shaft. The slider includes an actuator that protrudes from the slider to engage one of the cross gears to actuate a respective one of the plurality of valves.

Abstract: A method for automatically operating a heating system controller for heating an indoor space so that the indoor temperature measurement signals are kept a) at approximately or above a default set point when the automatically obtained outdoor temperature indicator signals reflect an outdoor temperature indicator that is above a freeze protection point, or b) at approximately a computed set point that is higher than the default set point when the outdoor temperature indicator signals reflect an outdoor temperature indicator that is below the freeze protection point. The computed set point can be based on an outdoor temperature indicator. A heating system comprising a furnace, a thermostatic controller, a sensor of indoor temperature operatively connected to the thermostatic controller, a receiver operatively connected to the thermostatic controller for receiving a signal indicative of an outdoor temperature indicator, wherein the thermostatic controller is configured to operate according to the method.

Abstract: An air conditioner (AC) indoor unit includes a housing having an inlet and an outlet; a heat exchanger arranged inside the housing; a blower fan for sucking in air at the inlet to be subject to heat exchange with the heat exchanger, and discharging the heat-exchanged air out of the outlet; and an air flow control device for controlling an air flow discharged from the outlet by sucking in air around the outlet. The AC indoor unit may control the direction of a discharged air flow without a conventional blade structure, thereby increasing an amount of discharged air, reducing circulation noise, and enabling design differentiation.

Abstract: An air-conditioning system includes a plurality of liquid desiccant in-ceiling units, each installed in a building for treating air in a space in the building. Dedicated outside air systems (DOAS) for providing a stream of treated outside air to the building are also disclosed.

Abstract: A system for circulating a volatile composition throughout at least one room is provided. The system includes a central communication unit capable of receiving incoming signals and sending outgoing instructions. The central communication unit comprises a memory configured to store settings. The system includes a volatile composition dispenser capable of delivering the volatile composition into the air. The volatile composition dispenser is communicably connectable with the central communication unit through a wireless communication link. The system includes an air handling device communicably connectable with the central communication unit and configured to move air throughout the at least one room upon receipt of an outgoing instruction from the central communication unit.

Abstract: Air conditioner units and methods for determining indoor room temperatures are provided. A method includes calculating a difference between a first temperature received from a first temperature sensor and a second temperature received from a second temperature sensor. The first and second temperature sensors are disposed within an indoor portion of an air conditioner unit, the first temperature sensor disposed proximate an indoor heat exchanger of the air conditioner unit, the second temperature sensor spaced from the indoor heat exchanger relative to the first temperature sensor. The method further includes modifying the second temperature based on the difference to obtain a corrected temperature, and outputting the corrected temperature.

Abstract: Methods and arrangements for computing a schedule for central air conditioning. Inputs are received, including: a monetary budget relative to a predetermined time period; an occupancy profile relative to the predetermined time period; and at least one of: electricity rates relative to the predetermined time period, and technical specifications of the central air conditioning. A target indoor temperature is determined based on the received inputs, with respect to different timepoints within the predetermined time period. An air conditioning schedule is determined for the different timepoints within the predetermined time period, wherein this determining includes reducing a quantitative measure relating to discomfort. Other variants and embodiments are broadly contemplated herein.

Abstract: A system for controlling the temperature in at least one room is provided. The system includes a central communication unit that is communicably connected with a memory configured to store at least one temperature set point. The system includes a volatile composition dispenser having a temperature sensor, wherein the temperature sensor is communicably connectable with the central communication through a wireless communication link. The system includes an air handling device communicably connectable with the central communication unit. The central communication unit compares incoming signals of temperature measurement from the temperature sensor with the temperature set point and sends outgoing instructions to the air handling device to heat or cool a room to the temperature set point if the temperature measurement is different from the temperature set point and to turn off if the temperature measurement is equal to the temperature set point.

Abstract: A system and method of operating an HVAC system, the HVAC system including a HVAC unit including a variable speed HVAC component in communication with a unit controller, an interface device in communication with the unit controller, and a single-speed system controller in communication with the interface device, the method including operating the interface device to receive a first conditioning signal from the system controller, operating the interface device to determine a temperature differential when the first conditioning signal is received, operating the interface device to transmit the temperature differential to the unit controller, operating the unit controller to transmit a speed signal based on the temperature differential, operating the interface device to receive a second conditioning signal, and operating the interface device to update the at least one set point estimate when second conditioning signal is received.

Abstract: An intelligent total air climate condition (iTACC) that includes an optically programmed adaptive system controller in electrical communication with at least one sensor and at least one fan motor that is capable adaptive operation of the fan motor based input signals from the at least one sensor.

Abstract: A central plant that generates and provides resources to a building. The central plant includes an electrical energy storage subplant configured to store electrical energy purchased from a utility and to discharge the stored electrical energy. The central plant includes a plurality of generator subplants that consume one or more input resources. The central plant includes a controller configured to determine, for each time step within a time horizon, an optimal allocation of the input resources and the output resources for each of the subplants in order to optimize a total monetary value of operating the central plant over the time horizon. The total monetary value includes revenue from participating in incentive-based demand response programs as well as costs associated with resource consumption, equipment degradation, and losses in battery capacity.

Abstract: An air temperature control unit comprising a refrigeration circuit (10, 6, 7, 7a, 12, 13, 14), a warm air chamber (4) housing a condenser (7) and a cool air chamber (5) housing an evaporator (10); wherein a water holding tank (24) is in fluid communication with the evaporator for collecting condensed water and a water pump (20) communicates the condensed water from the water holding tank (24) through a water purifying system (21, 22) to a water outlet device (23). A mixture of cooled air from the cool air chamber (5) and warm air from the warm air chamber (4) is used to maintain a predetermined inside temperature while excess cool air and warm air is exhausted to the outdoor environment. The system can therefore operate continuously to supply purified water without stopping the unit due to warm and cooled air being continually mixed to maintain the predetermined inside temperature, while excess warm and cooled air is exhausted to the outside environment.

Abstract: A heat exchange cell is described comprising a containment casing (11) comprising a rear wall (11d), a front wall (22) and a peripheral side wall (11c), a helically-shaped heat exchanger (13) comprising at least one tubular duct for the flow of a first heat transfer fluid coiled about a longitudinal axis of the helix according to a plurality of coils and mounted in the containment casing (11); a feeding zone of a second heat transfer fluid, intended for the heat exchange with the first heat transfer fluid, defined in the casing (11) coaxially and internally with respect to the heat exchanger (13); a first chamber (15) for collecting the second heat transfer fluid externally defined with respect to the heat exchanger (13) between a radially outer wall thereof and the peripheral side wall (11c) of the containment casing (11); and a second chamber (16) for collecting the second heat transfer fluid at least partially delimited by at least one separating element (14).

Abstract: An energy storing apparatus is provided which comprises: a first region having a thermostat which includes: a temperature sensor; a controller coupled to the temperature sensor; and a power-converter coupled to the controller; and a second region thermally coupled to the first region. An apparatus is provided which comprises: an interface to be coupled to an electric grid; a temperature sensor; a controller coupled to the temperature sensor; and a power-converter coupled to the controller, wherein the power-converter is to couple via passive devices to a heating element, wherein the power-converter is to apply power to the heating element according to a temperature sensed by the temperature sensor and a frequency of the electric grid.