| 摘要 |
The present invention relates to a novel means and a novel method for detecting a capacitance connected to AC power, which detect a sensor capacitance on the basis of a charge sharing phenomenon occurring due to a difference between voltages applied to a sensor capacitor and an auxiliary capacitor connected to a detection system when an AC voltage applied to the detection system alternates. The detection means for sensing a generation of a sensor capacitance CS by an approach of objects 18 includes: a sensor 14 configured to form a sensor capacitor cs between the objects 18; an auxiliary capacitor caux configured to have one side connected to the sensor 14 and the other side connected to a system ground GND1; a switching device 10 configured to control charging the sensor capacitor cs and the auxiliary capacitor caux; and a signal detector 22 configured to detect a voltage formed in the sensor 14 in synchronization with a change in size of system power applied to a detection system 20 when the sensor capacitor cs is formed between the object 18 connected to an external ground VG and the sensor 14. According to the present invention, since the sensitivity of a signal detected by a detection system is improved, a magnitude and a change amount of a sensor capacitance are stably acquired. |
