Abstract: A lighting apparatus includes a bridge circuit, a current source, a first LED module, a second LED module and a switch. The bridge circuit is used for rectifying an input AC power to generate a DC power. The current source receives the DC power to generate a driving current. The first LED module emits a first light of a first color temperature. The second LED module emits a second light of a second color temperature. The switch is coupled to the current source to change at least a resistance parameter corresponding to a current ratio between the first LED module and the second LED module to generate a mixed light of a mixed color temperature.

Abstract: An intelligent light-supplementing LED system for message signs and traffic lights includes multiple optical lenses and LED units which are respectively provided behind each of the optical lens. The LED units include at least two LEDs connected in parallel; multiple LED units are connected in parallel to form a parallel system unit, or multiple LED units are connected in series to form a serial system unit. The parallel system unit is connected to a constant current power supply or a constant current circuit. The serial system unit is connected to a constant current power supply, a constant-voltage DC source, or a constant current circuit. So if an LED fails to light up, the total current that passes through the LED unit will have no or little change.