Study for Teaching Material of Zero-Standby-Power Optical Sensor Circuit Through LED Photovoltaic Effect

Abstract

As standby power consumption of home appliances comprises 5.1% of the total household power consumption, it is necessary to reduce the standby power to contribute to an energy-saving society. In junior high school technology education, teaching material concerning standby power is considered to be of great importance, because it is fundamental to consider related environmental load and energy saving. In this study, through the LED photovoltaic effect, we investigated teaching materials that can handle standby power in junior high school technology education to enable the optical sensor circuit to light up automatically when it becomes darker while operating with zero-standby-power. An optical sensor circuit with zero-standby-power consists of a power supply, Pch MOSFET, and resistor as well as light reception and emission LEDs, whereas its operation can be adjusted using a resistor connected in parallel to the light reception LED. Moreover, by using a two-color LED, the integration of light receiving and illuminating LEDs was confirmed to be possible, and its usefulness as a teaching material was realized.