Vehicle motion and stop detector - has vibrator and reed switch and retriggerable monostable multivibrator sensing switch state

摘要

The detector picks up the 'go' and 'stop' conditions for use with e.g. a travelling time measurement system or 'stop-start' automatic systems in the detector system. A vibrator in the detector system has a leaf spring (1) attached to one end to the vehicle (2) and carrying a weight (3) on the other end, which operates a switch (6) as it vibrates. The weight preferably is permanent magnet, and the switch contains ferromagnetic reed contacts (4, 5) which are periodically closed by the vibrating magnet. Near the vibration zone may be mounted a high frequency proximity switch. The vibrator is mounted on an unsprung part of the vehicle, in partic. on an axle, suspension strut, or linkage and has a natural frequency between 10 and 20 Hertz. The switch mode is evaluated using a retriggerable monostable multivibrator (MV) with a pluse time of 1 or 2 seconds.