| 摘要 |
PURPOSE:To reduce the current consumption when the lifetime of a battery is alarmed, by reducing the duration of the 2nd pulse of the 2-second hand driving pulse applied to a step motor when the lifetime of the battery is detected. CONSTITUTION:When the voltage of a battery is normal, the bipolar pulse A is supplied alternately to a step motor with each second. Thus the second hand is moved with each second. When the lifetime of the battery is deteted, the 1st pulse P0 is supplied to the step motor. Then the adverse polar pulse P1 of a narrow duration is applied B to the step motor when the magnetic pole of a rotor turns up to the place near the static and stable position beyond the stator magnetic pole. Thus the second hand is moved with every 2 seconds to alarm the lifetime of the battery. |
