Koji Ogura

Low power consumption wireless wake-up module controlling AC power supply at household appliances

In this paper, we propose a wireless wake-up module controlling AC power supply to reduce power consumption at household electric appliances. The module is mainly composed of an Rx antenna, a wake-up IC, a microcontroller, an internal AC-DC converter, and two relays. The total current consumption of the module is about 15uA. The current consumption is around 1/300 that of a conventional module owing to the use of our developed low-power wake-up IC and the microcontroller with deep-sleep mode. The communication distance achieves 35m with output power of 18.3dBm under line-of-sight propagation.

Design method for low radiated emission of 85 kHz band 44 kW rapid charger for electric bus

Wireless charging technology for heavy-duty vehicles, such as electric buses, has been actively investigated with a view to accelerating deployment of an important form of eco-friendly transportation. We have been developing a wireless power transfer (WPT) system for rapid charging of electric buses. Most of the performance targets were achieved: the maximum electric power received was 44 kW or more, the maximum misalignment tolerance of the transmit and the receive charging pads was +/−10 cm or more, and the radiated emission was reduced to within the limits in accordance with the Radio Act. This paper presents a design method for low radiated emission, and the evaluation of the WPT system.