| 摘要 |
PROBLEM TO BE SOLVED: To prevent a short-circuiting current from being generated and to prevent trouble from being incurred by the short-circuiting current in startup.SOLUTION: A camera drive unit adopting a power source superposing system includes: a camera connection terminal CN to which a camera should be connected via a cable; a power line PL for supplying a drive current to the camera; a relay RLY inserted in series to the power line PL; and a serial circuit of a switch 50 and a current limit resistor R connected to the relay RLY in parallel. Before turning on the relay RLY, the switch 50 is turned on in the state where the relay RLY is turned off, and an inspection current is supplied to the camera side via the current limit resistor R. In the case where the inspection current is abnormally high, occurrence of short-circuiting is determined, and ON of the relay RLY is inhibited. |
