Automatic light dimmer for electronic and magnetic ballasts (fluorescent of HID)

摘要

An apparatus is disclosed for automatic light dimming of electronic and magnetic ballasts used for fluorescent or high intensity discharge lamps. A variable capacitant's limiting current is added in the lamps which provides lighting intensity controls without changing the ballast's operation frequency. Several capacitors are placed in line with a terminal for the lamp. The capacitor's switching capability is used to change the current received by the lamp. The amount of voltage can be controlled by either varying the supply voltage, or with an elimination sensor, or by manual potentiometer control.