how does a rain alarm using transistors (without IC 555) work????????????????
2006-09-18 03:21:51 · 3 answers · asked by Anonymous in Consumer Electronics ➔ Other - Electronics
a photo transistor and led may be used. when there is a rainfall a obstacle may be raised between the diode and transistor.
obstacle is made by a material which can float on water and it is placed in a tube between led and transistor. as soon as there is a ob stale transistor stops conducting and give signal to.
2006-09-18 04:33:27 · answer #1 · answered by Neo 2 · 0⤊ 0⤋
I'm not altogether sure, but my guess would be that water droplets hitting the alarm would close a switch, allowing electricity to flow and thereby sounding the alarm.
2006-09-18 10:30:48 · answer #2 · answered by Brian L 7 · 0⤊ 0⤋
If it falls on your face, it can wake up you.
2006-09-18 11:34:31 · answer #3 · answered by shubho_1986 1 · 0⤊ 0⤋