| 摘要 |
<p>A bi-level control system includes a plurality of slave units, each for connection to a respective ballast and HID lamp of a plurality of HID lighting fixtures, and a common control unit. Each slave unit includes a switched capacitor and a slave relay which has one input connectable to a common line of an AC power supply branch circuit powering the fixtures and another input adapted for receiving a line voltage signal. The control unit includes an output connected to the control inputs of each of the slave units by a single control line and switchably connected to line voltage. Dimming of the HID lamp is accomplished by switching line voltage to the output of the control unit which causes the slave relay to switch the slave capacitor into circuit with the HID lamp and ballast. Use of a single control line connecting each of the slave units to the control unit greatly reduces wiring over known systems. The control unit is also adapted to receive a control input from a sensor via a single input line, further reducing wiring.</p> |
