| 摘要 |
PURPOSE:To prevent lowering of efficiency due to heat loss during operation by connecting a resistor having resistance variable with the movement of a housing door in series with a safety switch disposed between an electronic load and a power supply while being interlocked with the door. CONSTITUTION:During an interval when a door 10 closes by some angle from open state, no current flows through a wiring 19 from a power supply 1 and a wiring 20 to an electronic load thus effecting the function of a safety switch 3. When the door 10 is closed by some angle, terminals 13, 14 protruding from the opposite ends of a contact 12 begin to contact with resistors 17, 18, respectively. At that time, a high resistor is inserted between the power supply 1 and the electronic load 2. Upon perfect closure of the door 10, the resistance goes zero. According to the constitution, rush current is prevented upon start of operation and deterioration of the contact in an interlock switch or erroneous function of an overcurrent preventive circuit is prevented while furthermore heat loss is eliminated during operation. |
