LED lamp

An LED lamp, comprising:

• a heat dissipation part comprising a heat sink;
• an optical part arranged at a front end of the heat dissipation part, the optical part comprising a main LED light source and an auxiliary LED light source, the main LED light source and the auxiliary LED light source being thermally attached to an end of the heat sink adjacent to the optical part;
• and
• an electric part arranged at a rear end of the heat dissipation part, the electric part comprising a shell, a circuit board and a rechargeable battery received in the shell, one end of the shell being connected to the heat sink, the other end of the shell forming a lamp cap, 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 LED light source being electrically connected to one of the first output end of the AC-to-DC power conversion circuit and the rechargeable battery through the switching controlling circuit, the main LED 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 LED light source being adapted for providing auxiliary illumination when the external AC power source is supplied normally and 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 interconnects the first output end of the AC-to-DC power conversion circuit and the auxiliary LED light source and wherein when the external AC power source is interrupted the switching controlling circuit electrically interconnects the rechargeable battery and the auxiliary LED light source.