| 摘要 |
PROBLEM TO BE SOLVED: To definitely discriminate disconnection of fuse from turning off of a power source, at low cost with a small size. SOLUTION: At a secondary-side circuit 5, an L output is provided when a power source is turned on. If a fuse 2 disconnects, a potential difference occurs between the phototransistors of first and second photocouplers 3 and 4. However, a transistor Tr2 is prevented from turning on by eliminating the potential difference. So, an output terminal 6 provides the same L output state as when the power source is on, and the L is outputted without generating an isolation signal. COPYRIGHT: (C)2004,JPO
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