Patent ID: 8434882
Filing Date: 2013-05-07
Classification: F21K,F21S,F21V,F21Y

Abstract:
1. An LED lamp, comprising: an optical part comprising a hollow light penetrable tube and an LED module received in the light penetrable tube, the LED module being provided with at least one first LED and at least one second LED, the at least one first LED and the at least one second LED of the LED module cooperatively functioning as a main light source for normal illumination, the at least one second LED of the LED module functioning independently as an auxiliary light, source for emergency illumination; a heat dissipation member received in the light penetrable tube, the LED module being thermally attached to the heat dissipation member; and an electric part comprising a circuit board, a rechargeable battery and two end covers, the circuit board and the rechargeable battery being arranged in the light penetrable tube, the two end covers being arranged at two opposite ends of the light penetrable tube, the circuit board forming an AC-to-DC power conversion circuit, a charging circuit and a switching controlling circuit thereon, wherein when an external AC power source is transferred to the AC-to-DC power conversion circuit, the AC-to-DC power conversion circuit converts the AC power source to DC power source and provides a first DC power source at a first output end thereof and a second DC power source at a second output end thereof, the charging circuit being electrically connected to the first output end of the AC-to-DC power conversion circuit to receive the first DC power source, the rechargeable battery being electrically connected to the charging circuit, the auxiliary light source being electrically connected to the rechargeable battery through the switching controlling circuit, the main light source being electrically connected to the second output end of the AC-to-DC power conversion circuit to receive the second DC power source and adapted for providing normal illumination when the external AC power source is supplied normally, the auxiliary light source being adapted for providing emergency illumination when the external AC power source is interrupted, wherein when the external AC power source is supplied normally the switching controlling circuit electrically disconnects the rechargeable battery and the auxiliary light source and wherein when the external AC power source is interrupted the switching controlling circuit electrically interconnects the rechargeable battery and the auxiliary light source; wherein a constant current/constant voltage controlling circuit is integrally formed on the circuit board, the constant current/constant voltage controlling circuit being electrically connected between the AC-to-DC power conversion circuit and the main light source, the constant current/constant voltage controlling circuit outputting a feedback signal to the AC-to-DC power conversion circuit for rectifying the output voltage and electric current of the first DC power source and the second DC power source, and wherein the constant current/constant voltage controlling circuit comprises a current sense resistor, a linear photocoupler, a pulse-width modulation integrated circuit (PWM IC), a Zener diode and a field effect transistor, the current sense resistor and the Zener diode being respectively used for providing an electric current feedback signal and a voltage feedback signal to the PWM IC via the linear photocoupler, to thereby rectify the waveform of the field effect transistor for stabilizing the output voltage and electric current of the first DC power source and the second DC power source.