| 摘要 |
A vehicle security system comprises an ignition lock 38 and a key 21 for operating the lock; the key 21 having a first and second actuation 28, 32 means for causing a transmitter 24 to transmit a coded unlock signal; the ignition lock 38 having control means 10 arranged to determine whether the key 21 is in the ignition lock 38 when the signal is sent. If the key 21 is not in the ignition lock 38 the cause of the signal transmission will have been the first actuation means 28, preferably a push button, and the system unlocks at least one door as well as re-mobilising the engine. If the key 21 is in the ignition lock 38 the cause of the signal transmission will have been the second actuation means 32, preferably a coil or reed switch (figure 2), and the system re-mobilises the engine only leaving the state of the door locks in an unchanged condition. The control means 10 determines whether the key is in the ignition lock 38 and thus whether the signal transmission is a result of the first or second actuation means 28, 32 by timing the delay between sending of and receipt of the signal. |
