Abstract: A light source device includes a tubular translucent cover. At one end side of the translucent cover, a translucent terminal fixing part to which one ground terminal is fixed is attached. At another end side of the translucent cover, a translucent terminal fixing part to which two power feeding terminals are fixed is attached. Inside the translucent cover, a placement plate is arranged, and a substrate is placed on the placement plate. On one surface (front surface) of the substrate, LED modules are mounted as a plurality of light sources. The LED modules mounted at ends of the substrate are located inside the terminal fixing parts. At another surface of the substrate located inside the terminal fixing part, a circuit component is mounted.

Abstract: A substrate with a light source mounted on one surface thereof, a placing plate, and a support part which supports the placing plate are disposed inside of a translucent cover at a position biased from a center side of the translucent cover to an inner surface side of the translucent cover. In addition, the substrate is disposed in such a manner that the light source is directed to the center side of the translucent cover. Further, a placing part of the placing plate on which the substrate is placed is disposed on the center side of the translucent cover from side parts of the placing plate supported by the support part.

Abstract: In a lighting apparatus including an emission unit and a constant current control part and/or a constant voltage control part for controlling a light quantity of the emission unit on the basis of a control signal, the constant current control part and/or the constant voltage control part includes light quantity control means for controlling the light quantity by changing the magnitude of a current and/or a voltage to be supplied to the emission unit in accordance with the control signal. Since no switching element is used in dimming level control of the emission unit, noise derived from an on/off operation of a switching element is not caused, and hence, noise may be reduced.

Abstract: A lighting apparatus includes a power unit supplied with power; an emission unit to be lit with power supplied from the power unit, with a light quantity of the emission unit being controlled in accordance with a control signal; and a power control part lighting the emission unit after the control signal is supplied. Since the emission unit may be lit after the control signal is supplied, the emission unit may be lit with a light quantity in accordance with the control signal from an initial stage, and hence a user may be prevented from feeling uncomfortable.

Abstract: When a voltage V detected by a voltage detecting section is lower than a first threshold value Vth1, an NPN transistor is turned on, a control terminal Ve is placed at a low level, and an overload protection circuit section halts the operation of a switching circuit section. When the voltage V detected by the voltage detecting section becomes higher than the first threshold value Vth1, the NPN transistor is turned off, the control terminal Ve is placed at a high level, and the overload protection circuit section resets the halt of the operation of the switching circuit section and makes the operation resumed.

Abstract: A lighting device includes: a light source module; a heat dissipation section accommodating a power-source circuit section for driving the light source module; and a base provided on a part of the heat dissipation section, wherein a cavity is formed in each of the heat dissipation section and the base, and a gas layer exists around circuit components such as a power-source circuit component and a heat generation component of the power-source circuit section, and at least the cavity of the base is filled with a thermosetting resin.

Abstract: In a heat dissipation device provided with a heat dissipation section that dissipates heat emitted from a transformer provided on a power-source board, the transformer is provided on an edge portion of the power-source board, and a heat conductor is inserted between the heat dissipation section and the transformer. Since the transformer is provided on the edge portion of the power-source board, the heat dissipation section and the transformer are located closer to each other.

Abstract: A lighting apparatus includes a power unit supplied with power; an emission unit to be lit with power supplied from the power unit, with a light quantity of the emission unit being controlled in accordance with a control signal; and a power control part lighting the emission unit after the control signal is supplied. Since the emission unit may be lit after the control signal is supplied, the emission unit may be lit with a light quantity in accordance with the control signal from an initial stage, and hence a user may be prevented from feeling uncomfortable.

Abstract: In a lighting apparatus including an emission unit and a constant current control part and/or a constant voltage control part for controlling a light quantity of the emission unit on the basis of a control signal, the constant current control part and/or the constant voltage control part includes light quantity control means for controlling the light quantity by changing the magnitude of a current and/or a voltage to be supplied to the emission unit in accordance with the control signal. Since no switching element is used in dimming level control of the emission unit, noise derived from an on/off operation of a switching element is not caused, and hence, noise may be reduced.

Abstract: When a voltage V detected by a voltage detecting section is lower than a first threshold value Vth1, an NPN transistor is turned on, a control terminal Ve is placed at a low level, and an overload protection circuit section halts the operation of a switching circuit section. When the voltage V detected by the voltage detecting section becomes higher than the first threshold value Vth1, the NPN transistor is turned off, the control terminal Ve is placed at a high level, and the overload protection circuit section resets the halt of the operation of the switching circuit section and makes the operation resumed.