Isolated voltage sensing using micro-resonator

A non-contact voltage sensor is proposed for realizing the isolation from the main circuit of the power line. The high voltage generates the electrostatic force. The sensing is based on the nature of the electrostatic force. The applying the electrostatic force is same with adding the negative spring to the resonator. The resonant frequency decreases with the voltage. The parallel plate electrode is used for sensing due to the strong gap dependency. The comb electrode is used for exciting the vibration of the resonator due to the little gap dependency. The relation between the shift of the resonant frequency and the applied voltage is well explained by the theory.