| 摘要 |
<p>PURPOSE:To surely detect a human body by using a PSD while the consumption of a battery is minimized. CONSTITUTION:A control circuit 8 makes an LED 11 emit light by turning on a transistor 14 and detects a human body in a detecting area by inputting detecting signals V1 and V2 from the light receiving signal of a PSD 18. A valve driving circuit 23 flushes a urinal. A battery 9 which is provided as a power source supplies electricity to each section through a constant-voltage circuit 10. When the light receiving level of the PSD 18 becomes lower due to light projecting operations, the control circuit 8 increases the current supplied to the LED 11 by turning on a transistor 15 so as to stabilize the light receiving level of the PSD 18.</p> |
