Abstract: According to one embodiment, a power supply device includes a first inductor, a current control section configured to limit a current value of an electric current flowing through the first inductor to a predetermined current value, the current control section including a first switching element of a normally on type and a resistor connected to a main terminal of the first switching element, a rectifying element connected to the current control section in series, and a second inductor magnetically coupled to the first inductor. The second inductor is configured to induce a voltage for turning on the current control section, when the electric current of the first inductor increases, to induce a voltage for turning off the current control section, when the electric current of the first inductor decreases, and to supply the induced voltage to a control terminal of the current control section.

Abstract: According to one embodiment, there is provided a power supply device includes a DC-DC converter and a protection circuit. The DC-DC converter includes a switching element of a normally on type, a current control element of the normally on type connected to the switching element in series and configured to control an electric current flowing to the switching element, and a rectifying element connected to the current control element in series. The DC-DC converter converts, according to ON and OFF of the switching element, an input first direct-current voltage into a second-direct current voltage, which has an absolute value different from an absolute value of the first direct-current voltage, and supplies the second direct-current voltage to a load. When an electric current equal to or larger than a predetermined value flows to the switching element and the current control element, the protection circuit cuts off the electric current.

Abstract: According to one embodiment, there is provided a control apparatus including a receiving section, a specifying section, and control sections. The receiving section receives a control signal. The specifying section specifies a control system corresponding to the control signal received by the receiving section. The control sections derive, according to the control system specified by the specifying section, control designated by the control signal received by the receiving section, and apply the derived control to a lighting device.

Abstract: A power supply apparatus of an embodiment includes a first filter, a second filter, and a switching power supply. The first filter and the second filter attenuate a common mode current to a level lower than a normal mode current. The switching power supply is connected between the first filter and the second filter, and supplies electric power to an illumination load via the second filter.

Abstract: According to one embodiment, a power supply circuit includes: a DC-DC converter which converts a first DC voltage supplied from a power supply flow path into a second DC voltage having a different absolute value, to supply the voltage to a DC load; and an overcurrent protection unit which is electrically connected to an end portion of the DC load on a low potential side, and performs feedback control of the DC-DC converter based on current which flows to the DC load. The DC-DC converter includes a normally-on type switching element. The overcurrent protection unit is electrically connected to the third electrode. When the current which flows to the DC load is greater than a reference value, the overcurrent protection unit changes the state of the switching element from the first state to the second state by decreasing the potential of the third electrode.

Abstract: According to one embodiment, there is provided a power supply circuit including a power conversion unit, a current regulator, a controller, and a controller power supply. The power conversion unit converts an AC voltage with a controlled conduction angle into a different voltage. The current regulator includes a branch path electrically connected to the power supply path and switches between a first state in which a part of a current flowing through the power supply path flows to the branch path and a second state in which a current flowing to the branch path is lower than that of the first state. The controller switches the current regulator to the second state in at least a part of a conduction period of a detected conduction angle and switches the current regulator to the first state in a blocking period of the detected conduction angle.

Abstract: According to one embodiment, there is provided a power-supply circuit including a substrate, a chopper circuit, a conductive member, first capacitative elements, and second capacitative elements. The substrate includes a mounting surface. The chopper circuit is provided on the mounting surface, includes input ends, output ends, and a switching element, and converts a voltage input from the input ends and outputs the voltage from the output ends according to switching driving of the switching element. The conductive member is adjacent to at least a part of the chopper circuit. The first capacitative elements are electrically connected between the input ends and the conductive member and capacitively couple the input ends and the conductive member. The second capacitative elements are electrically connected between the output ends and the conductive member and capacitively couple the output ends and the conductive member.

Abstract: According to one embodiment, provided is a power supply circuit including a power conversion unit, a controller, and an integrated circuit. The power conversion unit converts an AC voltage into a different voltage. The integrated circuit includes a current regulator that can switch between a first state in which a part of a current flowing through the power supply path flows to an input terminal and a second state in which a current flowing to the input terminal is lower than that of the first state, a controller power supply that converts a voltage into a driving voltage and supplies the driving voltage to the controller, a connection terminal for connecting an auxiliary power supply used for generating the driving voltage, and a protection circuit that blocks or decreases, when an auxiliary power supply voltage of the auxiliary power supply decreases, a current flowing to the input terminal.

Abstract: According to one embodiment, a lighting light source including a current control element and a voltage-dividing resistor is provided. The current control element has a first main electrode, a second main electrode series-connected with respect to a lighting light source, and a first control electrode for controlling a current flowing between the first main electrode and the second main electrode, and controls a current supplied to the lighting light source. The voltage-dividing resistor is parallel-connected with respect to the lighting light source and connected to the first control electrode, and inputs a voltage obtained by division of a voltage of the lighting light source to the first control electrode.

Abstract: A power supply apparatus of an embodiment includes a first filter, a second filter, and a switching power supply. The first filter and the second filter attenuate a common mode current to a level lower than a normal mode current. The switching power supply is connected between the first filter and the second filter, and supplies electric power to an illumination load via the second filter.

Abstract: A detection circuit according to embodiments includes a first circuit and a second circuit. The first circuit is turned OFF when an AC voltage to be input to a pair of input terminals is smaller than a prescribed value, and is turned ON when the AC voltage is equal to or higher than the prescribed value. The second circuit detects whether the AC voltage is an AC voltage leading-edge controlled by a dimmer, an AC voltage trailing-edge controlled by the dimmer, or an AC voltage having a continuous phase on the basis of at least one of the value of voltage and a gradient of the first circuit when the first circuit is turned ON while the first circuit is in the OFF state.

Abstract: Disclosed is an interface circuit including a rectifier circuit, a detection circuit, a first circuit, and a second circuit. The rectifier circuit rectifies an AC voltage input between a pair of input terminals. The detection circuit detects the AC voltage and outputs the result as a detection voltage. The first circuit is controlled to be turned on or off on the basis of an input first control signal, to cause a first current to flow between the input terminals in an on state and to cut off the first current in an off state. The second circuit is controlled to be turned on or off on the basis of an input second control signal, to allow a second current greater than the first current to flow between the input terminals in an on state and to cut off the second current in an off state.

Abstract: According to one embodiment, a power supply device includes a full-wave rectifier, a power converting circuit, and a partial smoothing circuit. The power converting circuit converts an output of the full-wave rectifier into a direct-current voltage according to a switching action of a switching element. The partial smoothing circuit includes, in series, a capacitor and a first diode connected in polarity opposite to output polarity of the full-wave rectifier. The partial smoothing circuit is provided on an output side of the full-wave rectifier in parallel to the power converting circuit. In the partial smoothing circuit, the capacitor is charged according to the switching action of the switching element of the power converting circuit. The partial smoothing circuit supplies charged electric of the capacitor to the power converting circuit via the first diode in a trough portion of an output voltage of the full-wave rectifier.