A lighting apparatus includes a surge voltage protector, a first rectifier, a first DC-DC converter, a first DC filter, a first constant current source, a second rectifier, a second DC-DC converter, a second DC filter, a second constant current source, a first PWM generator, a second PWM generator, a dimmer controller, a first light source and a second light source. The surge voltage protector is coupled to an external power for relaying an AC power. When there is a surge voltage is detected, the surge voltage protector disable routing the AC power. There are two or more paths of power circuits each generating a limited power. These power circuits are placed in the same container to simplify the overall design.