| 摘要 |
a key pad which comprises a plurality of buttons; an audible frequency oscillating unit for determinating an oscillating frequency of sound means; a first timer for a limit-time operation of the oscillating unit; an light emitting unit for visually displaying a code input of a user and an operation mode; a buffer for supplying power to operate the light emitting unit; a second timer for emitting light of the light emitting unit during a predetermined time; a memory for storing a secret number inputted through the key pad; an amplifying unit for amplifying an output signal of a controller which is generated when the code corresponding to the secret number is inputted to control a switching element; the switching element connected in serial with a start contact point of a key cylinder; the controller for controlling the amplifying unit, the first and second timers, the sound means and the light emitting unit; and a power supply voltage supplying unit connected to a contact point of key cylinder first state of an automobile, for supplying a constant voltage dropped to each part of circuits. |
