A double ended retrofit LED lighting device having two connecting terminals (L1, L2) at a first end for connection to a power source and two further connecting terminals (R1, R2) at a second end for further connection to said power source, the LED lighting device comprising: —at least one LED (D1) for emitting light, —an LED driver arranged for receiving an AC current from said power source and for driving said at least one LED based on said received AC current, —a filament circuit (RfilL) connected between said two connecting terminals (L1, L2) for supporting a filament current circulating back to said power source for indicating a presence of said LED lighting device to said power source, and—a pin-safety circuit comprising two pin-safety switches (SwLa, SwLb), wherein each pin-safety switch is connected to a respective separate terminal of said two connecting terminals (L1, L2) and comprises a changeover contact, wherein said changeover contact comprises: —a central node (CC) arranged to be connected to said power source; —a normally-closed node (NC) arranged to be connected to said filament circuit (RfilL); —a normally-open node (NO) arranged to be connected to said LED driver, such that said filament circuit (RfilL) is functionally disconnected, when said AC current flows to, or from, said LED driver.

A double ended retrofit LED lighting device having two connecting terminals (L1, L2) at a first end for connection to a power source and two further connecting terminals (R1, R2) at a second end for further connection to said power source, the LED lighting device comprising: —at least one LED (D1) for emitting light, —an LED driver arranged for receiving an AC current from said power source and for driving said at least one LED based on said received AC current, —a filament circuit (RfilL) connected between said two connecting terminals (L1, L2) for supporting a filament current circulating back to said power source for indicating a presence of said LED lighting device to said power source, and—a pin-safety circuit comprising two pin-safety switches (SwLa, SwLb), wherein each pin-safety switch is connected to a respective separate terminal of said two connecting terminals (L1, L2) and comprises a changeover contact, wherein said changeover contact comprises: —a central node (CC) arranged to be connected to said power source; —a normally-closed node (NC) arranged to be connected to said filament circuit (RfilL); —a normally-open node (NO) arranged to be connected to said LED driver, such that said filament circuit (RfilL) is functionally disconnected, when said AC current flows to, or from, said LED driver.

An LED tube lamp and an impedance detection method thereof are provided. The LED tube lamp includes a power supply module comprising an impedance detection controller, configured to perform, before the LED tube lamp being lighted up, an impedance detection to determine whether the LED tube lamp is electrically connected to a foreign external impedance in series. When the LED tube lamp is connected to the foreign external impedance in series, the impedance detection controller causes at least two transient variations to an operating current of the LED tube lamp and limits the operating current of the LED tube lamp to not exceed 5 MIU in root-mean-square (RMS), in which a duration of each transient variation does not exceed 1 millisecond when the impedance detection controller performs the impedance detection.

A light string with constant-current rectification includes a first constant-current rectification module, a second constant-current rectification module, and a light string formed by a plurality of light-emitting diodes connected in series. The first constant-current rectification module and the second constant-current rectification module each include rectifier diodes and a regulating circuit that maintains a constant current, an output terminal of the first constant-current rectification module is connected to an anode of the light string, and an input terminal of the first constant-current rectification module is connected to a power supply, an output terminal of the second constant-current rectification module is connected to a cathode of the light string, and a pair of conduction wires are connected between the input terminal of the first constant-current rectification module and the input terminal of the second constant-current rectification module.

An electronic driver for transforming an electronic ballast input voltage into an operating voltage for an LED lighting module. The driver includes a flicker eliminating circuit, which is adapted to operate in a saturation mode when the input voltage is below a threshold voltage. It operates in a switch mode when the input voltage is above a threshold voltage. A voltage drop in the flicker eliminating circuit in the saturation mode is higher than in the switch mode.

An electronic driver for transforming an electronic ballast input voltage into an operating voltage for an LED lighting module. The driver includes a flicker eliminating circuit, which is adapted to operate in a saturation mode when the input voltage is below a threshold voltage. It operates in a switch mode when the input voltage is above a threshold voltage. A voltage drop in the flicker eliminating circuit in the saturation mode is higher than in the switch mode.

LED lamp assembly comprising a safety switch, a plurality of connector pins arranged at first and second ends of the LED lamp assembly, the connector pins being adapted for electrical connection to a lamp fixture, a plurality of filament simulation circuits, wherein at least one of the connector pins at each of the first and second ends is electrically coupled to a corresponding one of the filament simulation circuits, a plurality of rectifier circuits, one or more LEDs electrically coupled to an output of the rectifier circuits, and a safety switch control circuit operatively coupled to the safety switch. At least one of the connector pins at the first end is electrically coupled via the safety switch to an input of a first one of the rectifier circuits, and at least one of the connector pins at the second end is electrically coupled to an input of a second one of the rectifier circuits. The safety switch control circuit is arranged to close the safety switch when it detects electrical power having a frequency above a predetermined threshold at the connector pins at the first or second ends of the LED lamp assembly.

A light fixture includes a first phosphor-converted light-emitting diode (“PCLED”) emitting light in a first PCLED wavelength range having first PCLED upper and lower bounds, a first direct light-emitting diode (“DLED”) emitting light in a first DLED wavelength range having first DLED upper and lower bounds, a second PCLED emitting light in a second PCLED wavelength range having second PCLED upper and lower bounds, and a second DLED emitting light in a second DLED wavelength range having second DLED upper and lower bounds. The first PCLED upper bound has a higher wavelength value than the first DLED upper bound. The first PCLED lower bound has a lower wavelength value than the first DLED lower bound. The second PCLED upper bound has a higher wavelength value than the second DLED upper bound. The second PCLED lower bound has a lower wavelength value than the second DLED lower bound.

A lighting device for a vehicle controls an emission intensity of each of a plurality of light emission units. The lighting device is configured to execute first control of controlling an irradiation area in accordance with a traveling direction of a vehicle, second control of controlling the irradiation area so that a degree of irradiation of light to a position of an object is reduced, and third control of controlling the irradiation area so that the degree of irradiation of the light to a position of a reflection object is reduced. The lighting device selects, as a final target value, a minimum value of a target value of an emission intensity for the first control, a target value of an emission intensity for the second control, and a target value of an emission intensity for the third control.

A lamp including a light source including at least one string of light emitting diodes (LEDs) within a tube body; end caps having contacts on each end of the tube body; driver electronics within the tube body including a filament detector portion provided by a passive resistance capacitor (RC) circuit that simulates the filament load of a fluorescent lamp when installed into a ballast containing fixture; and a power level selector switch in communication with the driver electronics for selecting the power level for powering the light source.