[14a-1C-1~10] 13.4 Si wafer processing /MEMS/Integration technology

[14a-1C-5] Isolated Voltage Sensor Using Gap-Closing Type Electrode

Naoki Nobunaga¹, Shinya Kumagai¹, Hiroki Ishihara², Makoto Ishii², 〇Minoru Sasaki¹ (1.Toyota Tech. Inst., 2.Yazaki Corp.)

Keywords:Isolated Voltage Sensor,Energy Management,Electrostatic Force

Many products, like the smart house, are going to control the energy flow in the near future. To realize such energy control, the sensors to measure the electrical current and voltage are indispensable. The sensors are required to be isolated to ensure reliability of the power line avoiding the short circuits accidents. Since the current generates the magnetic field, Hall sensors can measure the current in an isolated manner. The battery systems are constructed with the higher voltage to reduce Joule loss. There is no strong candidate of the compact, safe, and power-saving sensor for measuring the high voltage without the additional isolation circuit. We have proposed a sensing method based on the nature of the electrostatic force generated from the high voltage. A parallel plate electrode is used for sensing due to the strong gap dependency. Applying the electrostatic force is adding a negative spring to the resonator. The resonant frequency decreases with the voltage. An isolated voltage sensing method is demonstrated using only the electrical method which is suited to realize the compact sensor.