LED TUBE LAMP WITH OVERCURRENT AND/OR OVERVOLTAGE PROTECTION CAPABILITIES

摘要

A light-emitting diode (LED) tube lamp with overcurrent and/or overvoltage protection capabilities includes a lamp tube, a first rectifying circuit, a filtering circuit, an LED lighting module, and a protection circuit. The lamp tube has pins for receiving an external driving signal. The first rectifying circuit is for rectifying the external driving signal to produce a rectified signal. The filtering circuit is for filtering the rectified signal to produce a filtered signal. The LED lighting module includes an LED module, wherein the LED lighting module is configured to receive the filtered signal to produce a driving signal, and the LED module is for receiving the driving signal for emitting light. The protection circuit is configured to determine whether to enter a protection state, wherein upon entering the protection state, the protection circuit works to limit or restrain the level of the filtered signal.

主权项

1. An LED tube lamp with overcurrent and/or overvoltage protection capabilities, comprising:
a lamp tube, having a first pin and a second pin for receiving an external driving signal; a first rectifying circuit, coupled to the first and second pins, for rectifying the external driving signal to produce a rectified signal; a filtering circuit, coupled to the first rectifying circuit, for filtering the rectified signal to produce a filtered signal, the filtering circuit having a first filtering output terminal and a second filtering output terminal; an LED lighting module, coupled to the filtering circuit and including an LED module, the LED lighting module configured to receive the filtered signal and produce a driving signal, and the LED module for receiving the driving signal for emitting light; and a protection circuit, coupled to the filtering circuit, and configured to determine whether to enter a protection state, wherein:
the protection circuit is configured such that, upon entering the protection state, the protection circuit limits or restrains a level of the filtered signal;the protection circuit includes a voltage clamping circuit and a voltage division circuit;the voltage clamping circuit is coupled to the first filtering output terminal and the second filtering output terminal, and the voltage division circuit is coupled to the voltage clamping circuit and the second filtering output terminal; andthe voltage division circuit is also coupled to a positive terminal of the LED module to detect a voltage of the LED module, and is configured to receive a current detection signal, which represents a magnitude of current through the LED module.