| 摘要 |
A control circuit is provided for controlling the operation of a variable AC load (1), such as a metal halide lamp as used in photolithographic printing machines. The control circuit has a converter (3) connected with the load to receive the AC current arranged to pass through the load and to provide a DC output voltage representative of the amplitude of the load current magnetic amplifier (4) is connected to receive the DC output of the converter (3) and also connected between an AC voltage mains supply and the load to control the AC current through the load (1) in dependence upon the DC voltage applied to the magnetic amplifier (4). The AC load can alternatively be a tungsten or other incandescent lamp. |
