Abstract: An LED drive circuit that is connectable to a phase control type of light adjuster and receives a voltage based on an a.c. voltage to drive an LED load, the LED drive circuit has a structure which includes: an adjustment signal generation portion that generates an adjustment signal in accordance with a characteristic of a phase control type of light adjuster which is connected to the LED drive circuit; and an adjustment portion that receives the adjustment signal to adjust a characteristic for driving the LED load.

Abstract: An LED drive circuit that is connectable to an a.c. power supply via a phase control type light adjuster and drives an LED load, including a discharge portion that consumes energy of a resonance phenomenon generated by a light adjuster capacitance component of the phase control type light adjuster and a light adjuster inductance component of the phase control type light adjuster when a current holding portion of the phase control type light adjuster is turned on.

Abstract: There is provided an LED drive circuit that can be connected to an alternating-current power supply through a phase control dimmer and that drives an LED load, the LED drive circuit including: an LED current control circuit; a capacitance component and a resistance component that are connected in series between an input of the LED current control circuit and a reference potential; a switch element that is connected to both ends of the resistance component; and a switch control portion that turns off the switch element for a given period of time after a timing when the phase control dimmer is turned on and that turns on the switch element after the given period of time elapses.

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: Provided is an LED driving circuit (4), including: an impedance detecting section (7) for detecting an impedance value of a phase-control type dimmer (2); and an impedance adjusting section (6) for adjusting an impedance of the LED driving circuit (4) based on the impedance value detected by the impedance detecting section (7).

Abstract: An LED drive circuit connectable to a phase control type light adjuster includes a first reference voltage generation portion that generates a first reference voltage, a second reference voltage generation portion that generates a second reference voltage according to a phase angle of the light adjuster, an input voltage detection portion that detects a size relationship between an input voltage and a threshold value voltage, a current draw-out portion that draws out a current in accordance with the first reference voltage or the second reference voltage from an electricity supply line that supplies electricity to an LED drive portion, and a switch portion that in accordance with a detection result by the input voltage, detection portion, performs switching between an output from the first reference voltage generation portion to the current draw-out portion and an output from the second reference voltage generation portion to the current draw-out portion.

Abstract: An LED drive circuit is provided that can be connected to an alternating current power source via a phase-control light controller and drives an LED load.

Abstract: Provided is an LED driver circuit, to be connected to an AC power supply via a phase-control dimmer, for driving an LED load, including: a switching power supply part including a switching element and a switching current detection part; an LED current detection part; a first control part for controlling and switching the switching element so that a switching current has a desired current value based on a detection signal of the switching current detection part; a second control part for controlling and switching the switching element so that an LED current has a desired current value based on a detection signal of the LED current detection part; and a switch part for switching between control performed by the first control part when the phase-control dimmer is set to high brightness dimming and control performed by the second control part when the phase-control dimmer is set to low brightness dimming.

Abstract: There is provided an LED drive circuit that can be connected to an alternating-current power supply through a phase control dimmer and that drives an LED load, the LED drive circuit including: an LED current control circuit; a capacitance component and a resistance component that are connected in series between an input of the LED current control circuit and a reference potential; a switch element that is connected to both ends of the resistance component; and a switch control portion that turns off the switch element for a given period of time after a timing when the phase control dimmer is turned on and that turns on the switch element after the given period of time elapses.

Abstract: An LED drive circuit in which an alternating voltage is input and an LED is driven, and which can be connected to a phase control dimmer The LED drive circuit is provided with an edge detector for detecting an edge of the output voltage of the phase control dimmer; and a current extractor for extracting a current from a current feed line for feeding an LED drive current to the LED; wherein the value of the current extracted from the current feed line by the current extractor is varied in accordance with the detection results of the edge detector.

Abstract: An LED drive circuit which is connectable to a phase control type light adjuster, including: a first reference voltage generation portion that generates a first reference voltage; a second reference voltage generation portion that generates a second reference voltage according to a phase angle of the light adjuster; an input voltage detection portion that detects a size relationship between an input voltage and a threshold value voltage; a current draw-out portion that draws out a current in accordance with the first reference voltage or the second reference voltage from an electricity supply line that supplies electricity to an LED drive portion; and a switch portion that in accordance with a detection result by the input voltage detection portion, performs switching between an output from the first reference voltage generation portion to the current draw-out portion and an output from the second reference voltage generation portion to the current draw-out portion.

Abstract: An LED drive circuit in which an alternating voltage from a phase control dimmer is input and an LED is driven. The LED drive circuit comprises a phase angle detector for detecting the phase angle at which a phase control element inside the phase control dimmer switches from off to on; a switching power supply for feeding a current to the LED; a switching element connected in series to the LED; and a controller for controlling the switching power supply and the switching element in accordance with the output of the phase angle detector; wherein the controller places the switching element in an always-on state in a case in which the phase angle detected by the phase angle detector is equal to or less than a predetermined value, and the controller pulse-drives the switching element in a case in which the phase angle detected by the phase angle detector is greater than the predetermined value.

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: An LED drive circuit that is connectable to an a.c. power supply via a phase control type light adjuster and drives an LED load, including a discharge portion that consumes energy of a resonance phenomenon generated by a light adjuster capacitance component of the phase control type light adjuster and a light adjuster inductance component of the phase control type light adjuster when a current holding portion of the phase control type light adjuster is turned on.

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: Provided is an LED driving circuit (4), including: an impedance detecting section (7) for detecting an impedance value of a phase-control type dimmer (2); and an impedance adjusting section (6) for adjusting an impedance of the LED driving circuit (4) based on the impedance value detected by the impedance detecting section (7).

Abstract: An LED drive circuit that is connectable to a phase control type of light adjuster and receives a voltage based on an a.c. voltage to drive an LED load, the LED drive circuit has a structure which includes: an adjustment signal generation portion that generates an adjustment signal in accordance with a characteristic of a phase control type of light adjuster which is connected to the LED drive circuit; and an adjustment portion that receives the adjustment signal to adjust a characteristic for driving the LED load.

Abstract: An LED drive circuit is provided that can be connected to an alternating current power source via a phase-control light controller and drives an LED load.

Abstract: Provided is an LED driver circuit, to be connected to an AC power supply via a phase-control dimmer, for driving an LED load, including: a switching power supply part including a switching element and a switching current detection part; an LED current detection part; a first control part for controlling and switching the switching element so that a switching current has a desired current value based on a detection signal of the switching current detection part; a second control part for controlling and switching the switching element so that an LED current has a desired current value based on a detection signal of the LED current detection part; and a switch part for switching between control performed by the first control part when the phase-control dimmer is set to high brightness dimming and control performed by the second control part when the phase-control dimmer is set to low brightness dimming.

Abstract: An LED drive circuit in which an alternating voltage is input and an LED is driven, and which can be connected to a phase control dimmer The LED drive circuit is provided with an edge detector for detecting an edge of the output voltage of the phase control dimmer; and a current extractor for extracting a current from a current feed line for feeding an LED drive current to the LED; wherein the value of the current extracted from the current feed line by the current extractor is varied in accordance with the detection results of the edge detector.