| 摘要 |
<p>PROBLEM TO BE SOLVED: To prolong the life of a battery without uniformly lowering the detecting sensitivity by imparting a large current to a Hall element only if the high sensitivity is required. SOLUTION: A clamp sensor 10 of a battery type supplies an operating current from a battery 4 to a Hall element 2. The sensor 10 comprises an operating current supply circuit 11 in which a plurality of series circuits each having a constant-current element 3 and a switch 12 are connected in parallel with each other between the element 2 and the battery 4. The sensor 10 controls on or off of the respective switches 12 in response to the detecting sensitivity required for the element 2.</p> |
