Developing MEMS DC electric current sensor for end-use monitoring of DC power supply

A non-drive, non-contact MEMS 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 has been proposed. A micro magnet is integrated into the MEMS-scale DC sensor and the appropriate position for locating the micro magnet has been theoretically pinpointed. A macro-scale prototype DC sensor was therefore fabricated, and an impulse piezoelectric voltage output can be clearly detected out when a DC electric current was applied to a two-wire electrical appliance cord. 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. After the demonstration of the macro-scale prototype DC sensor, the MEMS-scale DC sensor has been then theoretically designed from the view point of reasonable output voltage measurements, and preliminarily micro-fabricated for further characterizations.