| 摘要 |
<p>PURPOSE:To detect a lid body being closed and generate an alarm without providing a leased line, etc., by providing a voltage lowering means which lowers the input voltage of a voltage detecting means when the lid body is closed while a switch means is ON state. CONSTITUTION:When the lid body is closed without turning off a power source 13 and a detection switch 9 is turned on, the connection point 20 between resistances R2 and R3 is grounded because the switch 131 is closed, and the potential at the connection point 20 is lowered greatly. Therefore, a comparing circuit 21 outputs a low output signal similarly to a case wherein a detected voltage value drops below a reference voltage owing to the voltage drop across a battery to activate an AND gate 23, so that a speaker 25 generates an alarm sound. Consequently, an alarm function for such a case is realized without providing an independent dedicated detecting circuit which detects the closed state of the lid body with the power switch ON nor providing a dedicated detection port to a CPU.</p> |
