摘要:
A power supply device according to one embodiment is configured to control a lighting of semiconductor light-emitting elements, wherein a dimming signal is canceled during a predetermined time period (T) from a timing immediately after power-ON, so as to light on light-emitting diodes to have a predetermined light amount, for example, a minimum light amount. After an elapse of the predetermined time period (T), cancellation of the dimming signal is released to light on the light-emitting diodes to have a light amount instructed by the dimming signal.
摘要:
In a power supply device according to one embodiment, a reference signal Vref1, which changes from a value corresponding to a maximum current in a full lighting state to that corresponding to a minimum current in case of a deepest dimming depth, and a reference signal Vref2, which changes from a value corresponding to a load voltage at the time of a maximum current in a full lighting state to that corresponding to a minimum current in case of the deepest dimming depth, are prepared in accordance with dimming depths of a dimming signal. In a shallow dimming depth region close to a full lighting state, the reference signal Vref1 is selected to apply constant-current control to light-emitting diodes in a current control mode. In a deep dimming depth region, the reference signal Vref2 is selected to apply constant-voltage control to the diodes in a voltage control mode.
摘要:
The present invention provides an LED lighting device including: a rectifying circuit having AC input ends connected to an AC source; a converter which has input ends connected to DC output ends of the rectifying circuit and output ends, to which an output capacitor is connected in parallel, connected to an LED, and lights the LED; a control unit for changing continued DC output current of the converter in accordance with a dimming degree; and a bypass circuit which is connected to the output ends of the converter in parallel with the output capacitor and makes bypass current flow, the bypass current being larger than lighting current, which flows through the LED, at least in the vicinity of a dimming lower limit.
摘要:
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.
摘要:
A current limiting circuit includes a power input terminal that is connected to an output terminal of a direct current power source to which an output capacitor is connected in parallel; a power output terminal to which an LED is connected; and a current limiting unit that supplies to the LED a load current to which an upper current value is set, supplies to the LED a load current lower than the upper current value at a normal condition, and supplies to the LED a load current higher than the load current of the normal condition and equal to or lower than the upper current value at an abnormal condition.
摘要:
According to one embodiment, a power supply for lighting includes a rectifying circuit, a smoothing capacitor, and a current control circuit. The rectifying circuit rectifies a phase-controlled alternating-current voltage supplied to between a pair of input terminals. The smoothing capacitor is connected to a high-potential terminal and a low-potential terminal of the rectifying circuit. A first electric current flows to the current control circuit in a period when an absolute value of the alternating-current voltage is lower than a specified value. After a second electric current larger than the first electric current flows when the absolute value of the alternating-current voltage increases to be equal to or larger than the specified value, the current control circuit is shut off to reduce a current value to be smaller than the second electric current until the absolute value of the alternating-current voltage decreases to be lower than the specified value.
摘要:
According to one embodiment, a lighting circuit includes a first power supply circuit, a first detecting circuit, a first control circuit, and a first protecting circuit. The first power supply circuit is supplied with power from a first power supply and outputs a direct current flowing in a first direction. The first detecting circuit detects a first detection value of an electric current flowing between the first power supply circuit and an output terminal. The first control circuit compares a first detection value detected by the first detecting circuit with a reference value and controls the first power supply circuit. The first protecting circuit is connected to the first detecting circuit and reduces an absolute value of the first detection value if an electric current flows in a direction opposite to the first direction.
摘要:
A lighting fixture capable of efficiently radiating heat of a lamp device may be configured to be attached to a socket device. In some examples, by attaching the lamp device to the socket device, a cap portion of the lamp device is brought into contact with a fixture body, and pressed against and brought into close contact with the fixture body by an elastic body. Heat generated by lighting of LEDs of the lamp device is conducted from the cap portion to the fixture body and efficiently radiated.
摘要:
A power supply for illumination includes a detection circuit and a control circuit. The detection circuit compares an AC voltage whose phase is controlled with a first threshold voltage so as to detect a variation in a conduction state of phase control in the AC voltage, and compares the AC voltage with a second threshold voltage lower than the first threshold voltage so as to detect a zero-cross point of the AC voltage, thereby detecting a conduction period of the phase control. The control circuit outputs an output current according to the duration of the conduction period.
摘要:
A light-emitting module in the embodiment includes a plurality of light-emitting elements, a power circuit, a power terminal, a feeding power terminal, and a substrate. The power circuit is configured to supply electric power to the light-emitting elements and performs lighting control. The power terminal is connected to the power circuit. The feeding power terminal is electrically connected to both ends of the power terminal. The substrate includes the plurality of light-emitting elements, the power circuit, the power terminal, and the feeding power terminal mounted thereon.