Passive piezoelectric DC sensor applicable to one-wire or two-wire DC electric appliances for end-use monitoring of DC power supply

A passive, non-contact piezoelectric DC electric current sensor to satisfy the increasing needs of DC power supply for monitoring the electricity consumption by either one-wire or two-wire appliance cord was proposed, and the sensing principle was schematically described and experimentally verified. A micro magnet was integrated into the proposed DC sensor and the appropriate position for locating the micro magnet was theoretically pinpointed. A prototype DC sensor was fabricated, and an impulse piezoelectric voltage output was detected when a DC electric current was applied to a two-wire electrical appliance cord, by using the constructed measurement setup for demonstration. A linear relationship between the detected peak value of the impulse output voltage and the applied DC electric current was further obtained based on the empirical measurements. In light of the above preliminary results, the proposed piezoelectric DC sensor is thus believed to be useful to various kinds of DC electricity end-use monitoring systems without consuming power electricity and using cord separators even in the case of the two-wire appliances.