Keyless entry system for automotive vehicle devices with weak-battery alarm

摘要

A keyless entry system can lock and unlock an automotive vehicle door, a trunk lid, a glove box and/or a steering column without an ignition key. The system comprises a transmitter producing a radio signal indicative of a preset unique code, and a controller receiving the radio signal and performing desired locking or unlocking operation when the code from the transmitter matches a preset code. A manual switch is provided to order the transmitter to transmit the code-indicative radio signal to the controller. The transmitter encloses a battery acting as a power source. A battery checker is provided to produce an alarm when the battery voltage becomes lower than a predetermined voltage.