| 摘要 |
A proximity sensor for sensing the proximity of a target comprising: an electrical component (20) for sensing the proximity of the target, said electrical component (20) having electrical properties that vary with the proximity of the target; an impedance component (21) having a known impedance and a first end connected to a first end of said electrical component; a switch (31) connected to switch between said first end of said impedance component (21) and a second end of said impedance component (21); a signal generator (22) connected to said second end of said impedance component (21) for generating an electrical signal for application to the impedance component (21) and electrical component (20); an analogue-to-digital converter (30) for receiving an electrical signal and for generating a digital signal; and a processor (23) connected to the analogue-to-digital converter (30) for receiving a digital voltage signal and for generating a proximity signal, wherein said processor (23) is adapted to control said switch (31) to switch to connect to said first and second ends of said impedance component (21) sequentially. |
