| 摘要 |
<p>The anti-theft alarm has two time delay circuits controlled by changing rates for two capacitors and with two relays and a transistorised logic. The owner sets the time delays for both circuits and locks the vehicle. When the doors are opened the first circuit becomes active and operates the alarm if it is not immobilised during this time interval. The alarm then sounds for the amount of time of the second circuit, and is reset for repeated operation unless immobilised. The system enables the owner to hide the small, compact alarm, and requires no outside immobilising contacts.</p> |
