PURPOSE: To inform on a fall of battery capacity by making no operation of a lock driving circuit or making operation of an alarm device through a lock controlling circuit when a voltage detection circuit detects that a voltage of a battery does not reach reference level.
CONSTITUTION: When a personal identification number is inputted from a key input device 11, power is supplied to a voltage detection circuit 15 to become in an operation state and, at the same time, an input signal is compared with the personal identification number set in advance, and if they are correspondent to each other, a lock controlling circuit 13 outputs an unlocking signal to a lock driving circuit 12. The lock driving circuit 12 unlocks based on the unlocking signal. Accordingly, a voltage of a battery 14 is detected by the voltage detection circuit 15, and when the voltage is lower than reference level based on the detected voltage value, the operation completes as it is, an alarm indication is made by an alarm device 16, if it is desirable at that time.
YOSHIDA NOBUYOSHI
JPH0266275A | 1990-03-06 | |||
JPS62112731U | 1987-07-17 | |||
JPS63226475A | 1988-09-21 |