| 摘要 |
<p>PURPOSE:To display the lifetime of a battery by providing a voltage detecting circuit which detects the voltage of a compact battery and an output circuit which outputs the detecting result of the voltage detecting circuit. CONSTITUTION:An IC card main circuit 4 consisting of a circuit of a RAM, etc., transfers the data to a computer 7, and a compact battery 2 supplies totally the power to an IC card. When a switch 3 is pushed, a voltage detecting circuit 1 works to detect the voltage of the battery 2. When the voltage of the battery 2 drops, the circuit 1 outputs a signal '1' to the base of a transistor TR 6 of an output circuit 8. Thus the TR 6 is turned on and turns on an LED 5. Thus it is possible to evade such an inconvenient case where the data are already erased when these data are inputted to the IC card since the lifetime of the battery 2 is displayed.</p> |
