| 摘要 |
PURPOSE:To enable a small number of elements to confirm data recording and to make a battery check, by using a forward voltage drop across LED as a reference voltage for the battery check. CONSTITUTION:As switch 14 is closed through release operation, control circuit 15 sends a data recording signal to light display device 17 for a constant time and at the same time, a recording confirmation signal turns on transistor T6 via resistance 2 to turn on LED4. At this time, the potential at point (a) is equivalent to a forward voltage drop across LED4. When the potential difference between points (a) and (b) exceeds voltage VBE of T8, SCR13 is triggered to stop the operation of control circuit 15, so that the external display will disappear. Then, SCR13 turns on to store the information that the battery voltage is less than a prescribed value and the following data can not be recorded. |
