A sensor made a debut that can measure power consumption of an electronics device easily without external power supply. Unlike the traditional sensor, the newly-developed sensor needs neither a battery nor an outlet. Developed by NEC, this sensor operates only with the force generated by the magnetic field in the area surrounding wires of an electronics device. Because it does not need a power source, it will be helpful to construct a system that monitors lots of electronics devices simultaneously and minimizes the total power consumption. The company gave a twist to the circuit design of power measurement. The sensor can operate with a very small power of about 1 milliwatt obtainable through the conversion of the force generated by the magnetic field. It also can tell the kinds of devices on the basis of wave pattern of current and detect the malfunction of the operation. Combined with software to manage electronics devices, it can manage power of idle devices to reduce the total energy consumption of an office and a household. NEC plans to apply this technology to the temperature sensor. The company will present the newly-developed sensor in the International Solid-State Circuits Conference being held in the U.S.