Exhaust gas intake blocking system for vehicle ventilation - initiates shut=down of fan or air intake at min. vehicle velocity

摘要

The exhaust gas intake blocking system is operated during slow movement or standstill of the vehicle, indicated by a velocity sensor cooperating with, or attached to, one of the vehicle wheels. The intake of the exhaust gases is prevented by disconnection of the electric ventilator fan, by closing the ventilation ducts or by switching the ventilation system into a recycling mode. The min. velocity for initiating the blocking of the exhaust gas intake may be detected by using the frequency of the AC signal superimposed on the DC signal provided by the alternator, driven by the vehicle engine. USE - Preventing exhaust gases being drawn into vehicle passenger space.