A keyless entry system for an automotive vehicle allows operation of a vehicle device or devices without the need for an ignition key or other mechanical keys. A user can simply depress a single push-button or operate another suitable type of switch to activate the system and operate the desired vehicle...http://www.google.com.au/patents/US4688036?utm_source=gb-gplus-sharePatent US4688036 - Keyless entry system for automotive vehicle with power consumption saving feature
