O'Reilly logo

Consumer Electronics by S. P. Bali

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

ULTRASONIC CAR SAFETY BELT SYSTEM

One of the results of car safety belt system developed by Mullard and the Ford Motor Co., means that even the car thief will have to strap himself in if he wishes to make off with his booty. The belt must not only be fastened but also positioned correctly across the wearer, Fig. 49.9(a).

As the block diagram in Fig. 49.9(b) shows, before the ignition will function the driver must occupy his seat activating a pressure switch beneath it, buckle the belt across his lap and close the belt switch. Provided the belt is worn correctly a 40 kHz signal emitted from an ultrasonic transmitter mounted in the belt is received by a detector built in the Windscreen pillar, which in turn completes the ignition circuit. If the ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required