| 摘要 |
PROBLEM TO BE SOLVED: To prevent a voltage drop in the projector of a lamp lighting device at smaller cost while causing no increase in weight of the projector. SOLUTION: A lamp lighting device 1 feeds power from its power source to its projector 4 through a connection cable 3 to switch on a lamp 22 arranged in the projector 4. The power source is provided with a constant-current control part 40 to feed constant voltage to the lamp 22. The control part 40 comprises a chopper constant-current circuit 41 for feeding constant current to the cable 3, a current detection circuit 42 for detecting current flowing in the cable 3, and a control circuit 43 for controlling the constant-current circuit 41 on the basis of the detected current. |
