Patent attributes
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.
