| 摘要 |
A seat is disclosed including a seating portion and a backrest and an occupancy detection system associated to said seat. The occupancy detection system comprises at least one sensing electrode arranged in said seating portion or said backrest and a control and evaluation circuit operatively coupled to said sensing electrode, said control and evaluation circuit for determining a parameter indicative of the capacitance of said sensing electrode with respect to the surroundings of said electrode, said capacitance being responsive to the presence of absence of an occupant sitting on the seat. According to the invention, said control and evaluation circuit comprises a voltage supply for providing a predetermined supply voltage, at least one reference capacitor having a first terminal and a second terminal, said first terminal being operatively coupled to ground potential; a controlled switching arrangement, said switching arrangement being arranged for connecting the at least one electrode alternately to said voltage supply and to the second terminal of said reference capacitor, and an evaluation unit configured and arranged for determining a parameter representative of the charging behaviour of the reference capacitor. |
