| 摘要 |
<p>PURPOSE:To achieve a larger current detectable range along with a smaller winding shape of a toroidal coil, by shunting a part of primary current flowing through a main path pattern to a jumper line through a shunt pattern. CONSTITUTION:An electric circuit 2 comprises a main path pattern 2a with a fixed width formed on a printed wiring board to run a current to be detected and a shunt pattern 2b which is branched off the main path pattern 2a with the width thereof less than that of the main path pattern 2a. A ring-shaped core is wound with a toroidal coil 4 and a jumper line 3 is mounted between one point Ha on the main path pattern 2a and one point Hb on the shunt pattern 2b piercing the coil. When a primary current flows through the main path pattern 2a, a relatively small branch current runs through the jumper line 3 through the shunt pattern 2b to generate the current proportional to the primary current in the coil 4. Thus, as the branch current branched partially off the primary current, changes in the secondary current are limited with respect to changes in the primary current thereby achieving a larger current detectable range regardless of a smaller size of the coil 4.</p> |
