Abstract: According to one embodiment, a lighting device includes a lighting circuit and a control circuit. The lighting circuit includes an output end to which an illumination lamp is connected, and lights the illumination lamp by a direct-current power. The control circuit controls the lighting circuit so that power consumption caused by a contact resistance at a connection part between the illumination lamp and the output end of the lighting circuit during whole light lighting of the illumination lamp does not exceed a specified value set to 8 W or less.

Abstract: According to one embodiment, a lighting device includes a lighting circuit. The lighting circuit includes a direct-current power supply and a DC-DC converter, and lights an illumination lamp by constant-current control. An output capacitor is connected in parallel to an output end of the DC-DC converter. A capacitance of the output capacitor is set to such a value that a peak value of a pulse-like current flowing when the illumination lamp is instantaneously detached from and attached to the output end of the DC-DC converter is one or more and four or less times a load current of the illumination lamp.

Abstract: An illuminating device includes a plurality of kinds of LEDs that emit light having different color temperatures; a plurality of LED lighting circuits that independently light the LEDs for each color temperature of emitted light; and a control unit that selects a first control changing illuminance of the LEDs as a whole by controlling the lighting of the LEDs and a second control changing the colors of light of the LEDs as a whole by controlling the lighting of the LEDs, and corrects an illuminance difference generated before and after the second control.

Abstract: In one embodiment, a lighting device includes an LED lighting circuit and an LED load constituted by a plurality of parallel circuits formed by connecting a plurality of LED elements in parallel, and a series circuit formed by connecting the parallel circuits. The series circuit is connected with an output terminal of the lighting device. In case one LED element becomes open fault mode in one of the parallel circuit, the other LED elements continue lighting. In case two or more LED elements become the open fault mode, the other LED elements also become the open fault mode, and all the LED elements turn off.

Abstract: A DC power source unit 37 is provided which boosts source voltage from a power source portion 36. A lighting circuit 38 is provided which supplies DC voltage to loads, the DC voltage being obtained by stepping down output current of the DC power source circuit 37. A control circuit 39 is provided which controls the lighting circuit 38 in accordance with at least either voltage or current of LEDs 25 and controls the DC power source unit 37 so that a ratio of output voltage to voltage of the LEDs 25 becomes a preset fixed ratio.

Abstract: According to one embodiment, a light source is mounted on one side of a base body, a cap is mounted on the other side of the base body and a lighting circuit is mounted in the cap. In the cap, a circumferential portion is formed, and a projection portion being projected from the other side of the circumferential portion and having an inner space opened to the one side is formed. The lighting circuit has a substrate and a plurality of components mounted on the substrate. The components include a first component group mounted on a center portion of the substrate and having a height stored in the projection portion and a second component group mounted on a peripheral portion of the substrate and having a smaller height stored in the circumferential portion.

Abstract: A dedicated power source for LED lamps capable of reliably detecting attachment of an LED lamp is provided. A dedicated power source has a DC power source portion, and includes a lighting circuit which receives power supplied from the DC power source portion and light-controls an LED lamp including an LED element and a detection resistor connected in parallel to the LED element and an attachment detecting portion for detecting attachment of the LED lamp based on a voltage level changing in accordance with attachment/detachment of the detection resistor by attachment/detachment of the LED lamp.

Abstract: According to one embodiment, there is provided a lighting fixture including a fixture body, straight-tube type LED lamps each having semiconductor light emitting elements, and a dedicated power source for lighting the semiconductor light emitting elements. The dedicated power source outputs current having a trapezoidal waveform a period of a peak portion of which is 54% or more of one cycle, and thus lights the semiconductor light emitting elements.

Abstract: An LED lamp system which suppresses flickering of an LED element is provided. The LED lamp system includes straight-tube type LED lamps each having LED elements and a dedicated power source for lighting the LED elements. The dedicated power source full-wave rectifies and smoothes a commercial AC power source, outputs constant current having a ripple factor of 1.3 or smaller and thus lights the LED elements.

Abstract: In one embodiment, a DC power supply unit includes a DC power supply source; a load circuit connected to an output end of the DC power supply source; a load state detection device to detect a load voltage or an electric quantity corresponding to the load voltage; and a control device to receive the detected output of the load state detection device. The control device controls a maximum output voltage of the DC power supply source so that the voltage difference between the maximum output voltage of the DC power supply source and the load voltage at the time of normal operation falls within a predetermined range in which arc discharge is suppressed.

Abstract: A light-emitting module includes a module substrate, semiconductor light-emitting elements and a connection substrate. On one face of the module substrate, a conductive layer is formed. The semiconductor light-emitting elements and the connection substrate are mounted on the conductive layer of the module substrate. Electric wires, which extend from a lighting circuit, are connected to the connection substrate. Power is supplied to the semiconductor light-emitting elements through the connection substrate and the conductive layer of the module substrate.

Abstract: A self-ballasted lamp includes: a base body; a light-emitting module and a globe which are provided at one end side of the base body; a cap provided at the other end side of the base body; and a lighting circuit housed between the base body and the cap. The light-emitting module has light-emitting portions each using a semiconductor light-emitting element, and a support portion projected at one end side of the base body, and the light-emitting portions are disposed at least on a circumferential surface of the support portion. A light-transmissive member is interposed between the light-emitting module and an inner face of the globe.

Abstract: Certain embodiments provide an LED lighting equipment including a lighting main body. An LED power device has a DC power source and a DC-DC converter having an input terminal connected to the DC power source and the DC-DC converter having an output terminal. An LED light source has a board and a plurality of LED packages; each including a plurality of LED chips connected in series. The LED packages are mounted on the board and connected in series to the output terminal of the DC-DC converter.

Abstract: A light-emitting device and an illumination apparatus are disclosed. A plurality of LED elements are connected in series between positive and negative lines, and first bypass capacitor is connected in parallel to the LED elements respectively. Each series circuit of a predetermined number of LED elements is connected in parallel to second bypass capacitors. As a result, with the negative power line set as a grounding point, the AC impedance at connection points of the series circuit of the LED elements against the ground is reduced. Thus, the erroneous lighting or “flicker” of each LED which otherwise might be caused by an external noise is prevented.

Abstract: There is provided an LED lighting device having a satisfactory temperature characteristic and a small amount of variation in output current. The step-down chopper is provided with a first circuit including the switching element, the impedance means and a first inductor connected in series and a second circuit including the first inductor and a diode connected in series. A self-excited drive signal generation circuit is provided with a second inductor magnetically coupled with the first inductor and applies a voltage induced in the second inductor to the switching element to keep the switching element on. A turn-off circuit outputs an output voltage when the voltage of the impedance means detected by a comparator exceeds the reference value, and the output voltage allows a switching element to turn on to short-circuit the output terminals of the self-excited drive signal generation circuit, resulting in that the switching element is turned off.

Abstract: The inverter circuit is feedback-controlled by a substantial current flowing into the discharge lamp, which is detected by the current detecting means. A high starting voltage is supplied to the discharge lamp with the operation frequency lowered by the control circuit after the end of a preheating action. The inverter circuit is controlled so that the current of the discharge lamp becomes a desired current value as soon as the current detecting means detects the current substantially flowing into the discharge lamp. The discharge lamp can be prevented from being instantaneously brightly lit without separately providing any structure for detecting lighting of the discharge lamp.

Abstract: The present invention provides a lighting device capable of controlling finely modulated light control without stopping other processing regardless of an operation clock. The light modulation signal generating portion calculates a cycle of a PWM signal based on the lighting state of lamp, which is detected by state detecting portion and a predetermined operation clock. A PWM signal of the cycle calculated by the state detecting portion is generated by the light modulation signal generating portion capable of generating the PWM signal corresponding to the cycle of a non-integral number of times of the operation clock, wherein the cycle of the PWM signal can be continuously and finely varied without stopping other processing regardless of operation clocks, and fine modulated light control is enabled.

Abstract: When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.

Abstract: When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.

Abstract: The invention provides a discharge lamp lighting apparatus. The apparatus comprises a first DC power supply circuit for converting an AC line voltage to a DC voltage, an inverter circuit provided with a switching element and a transformer, thereby the DC voltage supplied from the first DC power supply circuit is converted to a high frequency voltage for lighting a discharge lamp by an on-off switching operation of the switching element, an inverter controller for controlling the high frequency voltage output of the inverter by controlling the on-off switching operation of the switching element, a second DC power supply circuit for supplying a second DC voltage to the inverter controller through a power input end of the inverter controller, the second DC power supply circuit being provided with a detection winding inductively coupled to the transformer, thereby the second DC voltage being obtained by rectifying an induced current in the detection winding.