| 摘要 |
PURPOSE:To integrate correct entire mileage when a battery power source is connected by recording the mileage by an electronic method and recording and holding the same with a non-volatile memory even when said power source is disconnected. CONSTITUTION:A battery power source 1 is connected to a constant voltage power source 2, and the output thereof is connected to a microcomputer 3 for control. A comparator 5 compares the voltage of the power source 1 with a reference voltage Vr. A vehicle speed pulse signal is shown by 7. Mileage is integrated with the microcomputer 3 and the result thereof is displayed with a display element 9 through a driver 8. When the battery terminal is disconnected, the microcomputer 3 has the capacity enough to transfer the data in an RAM into an ROM by a capacitor 4 for backup. When the battery power source is turned on again, the capacitor 4 is recharged and the similar operations are accomplished. Thus, even if the battery power source is disconnected, the entire mileage is held by the backup mechanism; therefore, there are no problems. |
