Rain Detector

Make a rain detector with a few household items. A great project for the kids!

Step 1 Gather Materials

You will need a cup, a 9 volt battery, two paperclips, electrical tape, some wire, a light, and some salt. The only tools needed are a pair of wire cutters and some wire strippers.

Comments

[yrajput]

SAUL U R THE BEST DUDE!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[yrajput]

Really I am passing this comment at night at 11 o clock tommorow is my science exhibition ,you came like god 2 me INSTRUCTIBLES ROCK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[beehard44]

good if you want to detect rain 3 minutes after the first drops but what if you want to detect the first drops?

[puneet sidhwani]

itz a gud model.............. bla bla

[omkar_hummer]

could u also use baking soda?

[Yerboogieman]

can i use melted aluminum?

[AnarchistAsian]

ha ha TEH ALOOMINUMM DETECTER!!!!!!!!!

[AnarchistAsian]

hmm... maybe if i replace the light with a relay to trigger something...

[Bullseya]

The salt decrease the resistance so ... without the salt - no light.

[AnarchistAsian]

eh... it might still work... depends on the rain...

[arcticfox]

This is brilliant. Instead of light, it can be a buzzer or even a motor to close your windows etc.

[james sweeney]

what type of buzzer can i use

[Depechemodian]

Better civil servant with a transistor

[mamai]

what is the use of salt? does it really detect wqhen the rain comes?

[shop dweller]

cool post. Actually, the salt can be omitted in most cases. LEDs don't need a lot of current. I remember making a salt switch back in grade school (when LED's where still rare). It was pretty much the same as this except it used a big ol' incandescent flashlight bulb and D cell batteries. When you were using those big clunky bulbs (they needed huge current!)you had to put in the salt or it wouldn't work at all. And, the batteries were drained quite quickly. Thanks for the post!

[Rokko8652]

It says it helps the conductivity of the water

[jazeleh]

hi im new here.....just want to ask.....ammm what is the use of the salt and the paper clip? please.....

[radiorental]

Nice idea generator, a buzzer wuld be more fun. Kids will ask what is the point of a light if you can just stick your hand out to feel the rain. Some suggested improvements would be good such as an array made from a proto/bread board (the type with the ling of copper on the board ready for solder) or adding in salt to make conductivity better very cool hook in to circuitry

[bhadz20008]

WHAT WOULD BE THE CONCEPTUAL DESIGN OF THIS INVENTION?

[Yerboogieman]

instead of a light.....use a REALLY loud alarm...lmao

[WolvesOfWar]

nice idea for other projects simular. like an alarm.

[power]

nice invention i wouldn't thought of doing it myself

[latobada]

nice, i did this with a fountain, and a buzzer after a certain water level so it could be re-filled. this one is nice for kids though, i doubt they would be paitient enough to try it once it rains, but a good activity if it is raining!

[jtobako]

i think a grid across the bottom or a cup with a pointed bottom would be a better detector. the way this is set up it would have to be raining for a while for this to detect it.

[jason365]

It would be really fun to add an array of inputs and thereby measure the depth of the water. Then you could send the info to your computer. Of course you would need to secure your cup if you were going to keep it outside.

[ericcherry]

I had been toying with the idea of making such a thing for under my sink. I'm a bachelor and honestly don't spend much time in my kitchen, it'd be to the point of -too late- by the time I noticed that the sink had a slow link. A little LED hanging from the cupboard by the baseboards could save me some bucks. Clever!