Abstract: A lamp dimming system, designed to be added to existing HID fixtures with an absolute minimum of installation time and no external wiring is disclosed. Any existing ballast may be converted to a bi-level device for intelligent energy savings. The modification kit is wired in series with one of the lamp leads to effect both powering of the unit and control of the lamp. All timing and control is on an individual lamp basis so that the lamp temperature stabilization is completed before dimming is attempted. No external wiring, either to power the control unit or to effect control of the lamp dimming is required. Several versions are described. In one version the unit senses an occupant and stops dimming both of itself and other lamps in a network. In another version the unit receives a radio command to dim or brighten, which is inhibited until the initial power up delay sequence is completed. Self powered versions of both receiver and transmitter implementations are included.