Patent attributes
A power supply module is configured to provide, based on an external driving signal, a driving current for driving an LED tube lamp. The power supply module includes a detection path circuit, configured to establish a detection path which is capable of affecting an electrical signal on a power line of the power supply module when the detection path is turned on, and a driving circuit, electrically connected to the detection path circuit, and configured to produce the driving current based on the external driving signal. When the driving circuit is activated by receiving the external driving signal, the driving circuit enters into a first mode to detect whether a foreign external impedance is electrically connected to the LED tube lamp. When the foreign external impedance is detected, the driving circuit remains in the first mode, and when the foreign external impedance is not detected, the driving circuit enters into a second mode to produce the driving current. The driving circuit is further configured to obtain a dimming message from the electrical signal and adjust the magnitude of the driving current according to the dimming message when in the second mode.
