1. A lighting system, comprising:a light source operatively coupled to a power source;
a control unit operatively associated with the light source, and comprising:
a motion sensing device operable to provide a motion sensor output signal in response to a detection of motion;
a photosensor configured to sense ambient light and to generate a first photosensor output signal indicative of a first ambient light level and a second photosensor output signal indicative of a second ambient light level;
a processing unit responsive to the motion sensor output signal, the first photosensor output signal, and the second photosensor output signal so as to control illumination of the light source by providing a first trigger signal based on the first photosensor output signal, a second trigger signal based on the second photosensor output signal, and a third trigger signal based on the motion sensor output signal; and an amplifier configured to respectively amplify the first trigger signal, the second trigger signal, and the third trigger signal,
wherein the control unit further comprises: an optocoupler, an RC filter, a first rectifier, and a second rectifier, the optocoupler including a light-emitting element coupled to a light-sensitive element, each of the first and second rectifiers including a set of diodes connected in a closed loop configuration;
wherein the light source is responsive (a) to the first amplified trigger signal to illuminate at a first brightness level, (b) to the second amplified trigger signal to illuminate at a second brightness level, and (c) to the third amplified trigger signal to illuminate at a full brightness level, the full brightness level being greater than the second brightness level, the second brightness level being greater than the first brightness level.