2021 Volume 29 Issue 2 Pages 334-339
In this paper, is proposed a battery-less wireless sensor to generate power at door operation and to transmit temperature and humidity information. The power generation device is a U-shaped 1 mm thick iron frame with 8 × 1 × 32 mm3 Fe-Ga alloy laminated and coil wound, and a mechanism to generate free vibration by the movement of door using the desorption of permanent magnet attached to the frame tip. By attaching a capacitor which cancels the inductive reactance of the coil to the voltage doubler rectifier circuit, the storage energy over 3 mJ sufficient for the operation of wireless module (920M Hz) was generated in the capacitor of 220 μF, and it succeeded in transmitting temperature and humidity data in 1 time operation. In addition, the system was mounted on the door of clean rooms, and it succeeded in carrying out the transmission and reception without the lack of the data, when the monitoring test for 2 weeks was carried out.
