| 摘要 |
<p>PURPOSE:To prevent the bursting and firing of a primary battery even if a charging prevention circuit is failed by providing a current fuse between the cathode of the primary battery and a ground. CONSTITUTION:A primary battery 104 is arranged on a location which is backward a main body case 601 and does not overlap with a keyboard unit 607. A charging prevention circuit 608 mounted on a main substrate 606 is connected with a connector 604 by a comparatively long pattern 609. Because the danger of the charging to the primary battery 104 occurs via the pattern 609 when the primary battery 104 and a constant voltage power source terminal is short- circuit formed by a state conductive foreign matter, etc., intruding from the clearance of the main body case 601 and the keyboard unit 607, a current fuse 105 is connected between the cathode of the primary battery 104 and ground thing of the main substrate 606. Thus, the destruction of the primary battery 104 is prevented because the current fuse 105 is fused and the charging circuit for the primary battery 104 is released when the charging circuit is formed by foreign matter, etc.</p> |
