System description

This system implements a seat warning detector for three seats in a vehicle. Each seat has a presence senor (Person sitting or not) and belt (fastened or not fastened). The following table shows the possible cases for one of the seats.

Presence sensorBelt sensorOutput
0 (Empty seat)0 (Belt fastened)0V
0 (Empty seat)1 (Belt not fastened)0V
1 (Occupied seat)0 (Belt fastened)0V
1 (Occupied seat)1 (Belt not fastened)12V


The system provides a logical 1 (12V) when there is a person sitting and the belt is not fastened. If this condition occurs in any of the seats, the output will be set to 12V.

This system is supplied at 12V DC by the manufacturer and delivers 12V DC at the output.