Patent ID: 10184617

Abstract:
The present invention relates to a LED tube (1) for retrofitting in a fluorescent tube lighting fixture having a preheat phase during which the fluorescent tube lighting fixture is arranged to preheat filaments of a fluorescent tube, the LED tube (1) comprising: an array of LEDs (2), a LED driver (4) for driving the array of LEDs (2), a first pair of contact pins (8, 0) at a first end (12) of the LED tube (1) and a second pair of contact pins (14, 16) at a second end (18) of the LED tube (1) for connecting the LED tube (1) electronically and mechanically to the fluorescent tube lighting fixture, the first pair of contact pins (8, 10) being connected forming a first circuitry, the second pair of contact pins (14, 16) being connected forming a second circuitry, the LED driver (4) being connected between the first circuitry and the second circuitry, and a temperature controlled switch (20) having an open state and a closed state, and being arranged to adapt the closed state when heated, such that a current path between the first circuitry and the second circuitry is obtained, wherein a preheat current passing between the first pair of contact pins (8, 10) during the preheat phase of the fluorescent tube lighting fixture is arranged to heat the temperature controlled switch.