Abstract: A security lighting system and method are intended to dispel and/or affect unwanted humans or animals by providing lighting that varies with a suitable switching frequency, such as between 5 and 70 Hz. The lighting of a light source of the system may be varied by a control unit as to intensity, color, pattern etc., with a preferred switching frequency being between about 15 and 20 Hz for humans. A proximity detector may be provided to activate the system when an unwanted presence is detected. Such varying lighting causes feelings of physical and psychological discomfort, which have found to be effective in chasing away animals and dispelling or disorienting humans.

Abstract: A driver (10) for driving a gas discharge lamp (L) comprises a current generator (1; 2) for generating a lamp current with a main lamp current component and, for arc-straightening purposes, a ripple current component. A controller (3) controls the current generator such as to set the ripple frequency (fR) and ripple amplitude (M). A memory (5) contains data defining a set point (SP) for the ripple frequency and ripple amplitude. A measuring device (4) provides at least one measuring signal indicative of arc curvature and arc stability. The controller is capable of operating in a ripple optimization mode in which the controller makes small adjustments to the ripple frequency and ripple amplitude to find improved arc-straightening, and, if such improvement is found, controls the current generator on the basis of the adjusted set point or otherwise resumes operation on the basis of the original set point (SP) in the memory (5).

Abstract: The present invention provides a security lighting system and method, that are intended to dispel and/or affect unwanted humans or animals (20) by providing lighting that varies with a suitable switching frequency, such as between 5 and 70 Hz. The lighting of a light source (14a, 14b) of the system may be varied by a control unit (12) as to intensity, color, pattern etc., with a preferred switching frequency being between about 15 and 20 Hz for humans. A proximity detector (16a, 16b) may be provided to activate the system when an unwanted presence is detected. Such varying lighting causes feelings of physical and psychological discomfort, which have found to be effective in chasing away animals (20), and dispelling or disorienting humans.