AUTOMATIC LIGHT ATTENUATOR FOR ELECTRONIC AND MAGNETIC BALLASTS (HIGH-INTENSITY DISCHARGE OR FLUORESCENT)

摘要

The invention relates to an apparatus which used for the automatic attenuation of the light from electronic and magnetic ballasts used for high intensity discharge or fluorescent lamps. According to the invention, a limiting current from the variable capacitor is supplied to the lamps, which provides illumination intensity controls without altering the operation frequency of the ballast. Various different capacitors are positioned in the common line of the lamp(s). The capacitors are switched with slow transient in order to change the current received by the lamp. The illumination level can be controlled by varying the supply voltage using power line communication controls, with an illumination sensor or by means of a manual potentiometer control.