Auto Car Wiper

Hello..

I was thinking to make an auto car wiper. I want to know what is the
best sensor to use for the circuit. Hope you guys can help me.

Thanks.


-harore-
http://www.hobbyelectroniccircuits.com

 

How do you intend to wipe out a whole car???????????
For havens sake, the required battery power alone
will be enormous.

 

As in windshield/windscreen wiper?

They use mechanical switches for sensors.

 

what I meant is windshield wiper. sorry for the trouble. I want to make
the wiper automatically switched on when rain drops to the windshield.
My car is just a small car I used for electronic project. The problem
is I don't know what sensor I need to use. What do u suggest?

 

I think a conductive grid is usually used, don't have it "live" all the time
as that'll wear ir out, just ping it for a microsecond or so every few seconds.

Bye.
Jasen

 

Imagine if you will, the wire antenna that is laid against the inside of the
windshield glass. 2 wire side by side carrying a small signal that is
coupled between the wires. When the outside of the windshield gets wet, the
water acts as capacitor connected to the 2 wires and thus you get more
signal on the receive wire. There you have a capacitive coupling rain
sensor. You can use that to activate the wipers with of course the signal
and trigger circuits. Hope this gives you ideas.

 

That's why it will have an alternator on board.

Puckdropper

 

That's an interesting idea. I've seen "rain detection" circuits that are
basically two wires spaced a drop's space apart, and I was thinking
that'd never work for a windshield. With your idea, it's possible to
cover a much larger area and thus turn the wiper on when needed.

Puckdropper

 

Thanks guys for the help. Really appreciate it



harore
http://www.hobbyelectroniccircuits.com

 

Came across a circuit the other day similar to what Mr. Thompson was
suggesting. That's how I'd do it too - less problems with electrode
corrosion and dirt build up giving false positives - like you'd run
into with a contact sensor.

http://www.imagineeringezine.com/PDF-FILES/capgage.pdf

It is for a level gauge in a tank, but could be adapted for on/off
indications easily enough. I doubt you'd need a crystal controlled
oscillator for it, and moving the frequency higher may make it more
sensitive with less electrode area . . .

Another possibility is using a mechanical humidity sensor - nylon rope
webbing, under tension, seems to elongate when it is wet. Its
possible to make a decent mechanical humidity sensor from horse hair
(sold for violin bows) - but that wouldn't be ideal for outside.

 

"I was thinking to make an auto car wiper. I want to know what is the
best sensor to use for the circuit. Hope you guys can help me."

Re: You can purchase window defrost strip repair "paint" at automotive
parts outlets. This is a conductive paint that is used to repair the
heat strips that are laminated onto automotive windows; usually the
rear window. It adheres well to glass. You could apply this to the
outside of the windshield in two, closely spaced strips, to act as the
sensor. When the glass between the strips becomes wet, this would
provide the conductive path for your wiper activation circuit. I
suppose you would have to experiment with spacing and placement of the
"strips".

Dan Akers