It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely on
it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

Rick Hughes coughed up some electrons that declared:

It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

Stainless steel would last forever, more or less. When I was a kid, I made a
water level detector for a caravan water tank (Aquaroll) with 5 bits of
stainless rod bent around the pipe-straightener that dipped in the
container. One common and 4 sensor points. Connections were done with
crimped stainless wire, sleeved and run out of the container, then soldered
into a DIN plug. Worked very well, never corroded.

Anyway I digress.

Perhaps get something like (anything will do as long as it's got stainless
rod):

http://cgi.ebay.co.uk/NEW-PATON-CALV...em?refid=store

Cut short strips, solder wires on the ends (Bakers Fluid and silver solder
to tin the stainless worked for me, but that's dated information, may be
other ways).

Lay in a pattern like this:


----------------
================
----------------
================
----------------
================

Connect the --------- together, connect the ============ together, but
separate from the ----------

Epoxy down on a bit of plastic (outside of a waterproof box if you want keep
it self contained, with the electronics inside). Space rods so that a drop
of rain can couple two rods.

If you don't fancy trying to solder the rod, what I did was hacksaw a 1/8"
slot in the end, then use a heavy vice to crimp a bit of wire in the slot.
If you're using copper wire, a bit of solid core from some mains twin+earth
might work, but cover the crimp with epoxy.

Well, that's my theory. Sure there'll be many more equally good ideas. The
above will cost you a few pounds depending if you get lucky at the pound
shop for the stainless and whether you need to buy appropriate solder and
flux.

Cheers

Tim

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Rick Hughes"
saying something like:

I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

Stainless steel probes - I've never tried soldering to stainless, it
might be ok.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on
it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.



Isn't a Scuba kit supposed to be wet? and how do hang a boat on the washing
line?

George wrote:

Isn't a Scuba kit supposed to be wet? and how do hang a boat on the washing
line?



You'd be amazed how much a wetsuit will smell if left damp for a few
days. And even synthetic sails will get mildew stains.

OP might like to google for wetsuit enzyme too.

Andy

On Thu, 28 Aug 2008 20:24:44 +0100, Rick Hughes wrote:

It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

Plenty of kist available try Maplins. As you say the sensor is the biggest
problem. How about a few square inches of veroboard? Give it a rub over
with some fine sand paper to remove the protective lacquer and connect
alternate strips to each sensor wire. Copper will last for ages outside,
not so sure about the SRPB board that might give up in a year or two.

--
Cheers
Dave.

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.



Send out the bald man?

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on
it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.



Replace the coins sensor with....
A spoon and a tilt switch, spoon should have a small brass tube piece welded
directly in the center of its balance.
take a longish bolt and some nuts that will fit through the brass tube
piece,this nut and bolt will go through a wooden upright support drill on
both sides at exactly the same height,feed the bolt through hole on one side
and screw on 2 nuts,take spoon and feed it on to bolt,put another 2 nuts on
the bolt feed bolt through the other hole and put a last bolt on the end.
Now then tighten the 2 end nuts (1 on the bolt head side) so that the bolt
does not move in the holes,glue(araldite or some strong glue) the tilt
switch to the end of the handle and connect to a buzzer and battery,tighten
the 2 center nuts(possibly need washer either side of the nuts?) against the
brass tube ever so slightly but enough to give the spoon freedom to move.

get some water and pour droplets onto the spoons hollow and it should drop
down forcing the tilt switch to activate the buzzer,the 2 center nuts will
probably need adjusting for sensitivity.

Any good panel? :-)
That came of the top of me head whilst waiting for the kettle to boil.

Water detector alarm
http://www.greenweld.co.uk/acatalog/...er_Alarms.html

http://www.dalbani.co.uk/index.php

On Fri, 29 Aug 2008 00:46:14 GMT, George wrote:

A spoon and a tilt switch, ...

Complicated, why not use the handle end of the spoon as one contact and a
bolt head as the other. It won't detect light rain fall either, even if
you put a large funnel over the bowl of the spoon to capture more rain.

What you have described is the basis of a "tipping bucket" rain gauge.
What you have missed is that the bucket (spoon) tips it empties of water
and is ready for the next volume of rain.

This would only signal a pulse to the detector, so that would need to
trigger something to sound the alarm long enough to be noticed. Unlike the
"wet plate" detector which will sound for as long as the plate is wet.

--
Cheers
Dave.

Waldo Point wrote:

"Rick Hughes" wrote in message
...

It would be handy to be able to have a detector that can give an
audible signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't
rely on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ...
large enough surface are to catch first few drops of rain, stable
enough not to corrode in a couple of weeks.



Send out the bald man?

Send out a tall man for early warning of rain.
;-)

On Aug 28, 8:24*pm, "Rick Hughes" wrote:
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) *and can't rely on
it staying dry long enough to dry kit.

I have found a link to one projecthttp://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

These sort of circuits are generally kids' projects. If you want the
sensor to last you need to avoid any dc on the sensor, to avoid
galvanic corrosion. Generate ac and feed it to the sensor, using it
with another C or R as a voltage divider. Level of output voltage
drops when wet, use that to trigger your yes/no circuit.


NT

In article ,
Owain writes:
Rick Hughes wrote:
Anybody anything better .... the key would seem to be the sensor ...
large enough surface are to catch first few drops of rain, stable enough
not to corrode in a couple of weeks.

Veroboard with alternate strips commoned to each sensor wire?

That was the basis of one in Everyday Electronics which I made
well over 30 years ago. You need to heat it too (a few low power
resistors are sufficient), or it can takes ages to dry out and
stop reporting rain, when the rain stopped ages beforehand,
and it might otherwise be triggered by condensation.

I think I've seen a simple module in Maplin which works much
the same way.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

An optical sensor might be better, what do they fit to modern cars these
days? the auto windscreen wiper seemed to work OK on the Peugeot 807 I used
to have .
Don

On Sun, 31 Aug 2008 08:31:30 +0100, in uk.d-i-y "Donwill" popple
@diddle .dot wrote:


"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

An optical sensor might be better, what do they fit to modern cars these
days? the auto windscreen wiper seemed to work OK on the Peugeot 807 I used
to have .

Yes, wife has a 206 and its auto wiper works well (provided you can
remember the switch flick-sequence to activate it!). And it's inside, so
doesn't get wet. It detects wetness on the other side of the glass.
Could it use a light beam totally reflected at the glass surface, but
passing through when the surface is wet - or the other way round? It has
a very fast response, generates single sweeps in light rain.

Phil

Phil Addison wrote:
On Sun, 31 Aug 2008 08:31:30 +0100, in uk.d-i-y "Donwill" popple
@diddle .dot wrote:

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.
An optical sensor might be better, what do they fit to modern cars these
days? the auto windscreen wiper seemed to work OK on the Peugeot 807 I used
to have .

Yes, wife has a 206 and its auto wiper works well (provided you can
remember the switch flick-sequence to activate it!). And it's inside, so
doesn't get wet. It detects wetness on the other side of the glass.
Could it use a light beam totally reflected at the glass surface, but
passing through when the surface is wet - or the other way round? It has
a very fast response, generates single sweeps in light rain.

Phil

Our Mazda 3 Sport has an optical system. I assume it works on uneven
spread of light when raindrops fall on the outside of the windscreen
where the sensor is on the inside. Trouble is I often drive it in the
dark on unlit roads and if there are not a lot of oncoming headlights it
does not work well enough. My wife tends to use it in daylight and
reckons the system is brilliant.

On 28 Aug, 21:10, "George" wrote:
"Rick Hughes" wrote in message

...





It would be handy to be able to have adetectorthat can give an audible
signal when it starts torain.

I often have sports kit outside drying (Scuba, boat etc) *and can't rely
on
it staying dry long enough to dry kit.

I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops ofrain, stable enough not to
corrode in a couple of weeks.

Isn't a Scuba kit supposed to be wet? and how do hang a boat on the washing
line?- Hide quoted text -

- Show quoted text -

when in use yes :-)

afterwards you need it to dry ... as to boat, typically covers left
off it trying to dry it out, usually gets close to dry ... then it
rains, and before I notice ... 'tis all wet again.

On 30 Aug, 18:37, (Andrew Gabriel) wrote:
In article ,
* * * * Owain writes:

Rick Hughes wrote:
Anybody anything better .... the key would seem to be the sensor ...
large enough surface are to catch first few drops ofrain, stable enough
not to corrode in a couple of weeks.

Veroboard with alternate strips commoned to each sensor wire?

That was the basis of one in Everyday Electronics which I made
well over 30 years ago. You need to heat it too (a few low power
resistors are sufficient), or it can takes ages to dry out and
stop reportingrain, when therainstopped ages beforehand,
and it might otherwise be triggered by condensation.

I think I've seen a simple module in Maplin which works much
the same way.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

I made the same one ... I even still have that issue of the magazine !
The problem will be long term stability with veroboard in open air ...

On 30 Aug, 18:37, (Andrew Gabriel) wrote:
In article ,
* * * * Owain writes:

Rick Hughes wrote:
Anybody anything better .... the key would seem to be the sensor ...
large enough surface are to catch first few drops ofrain, stable enough
not to corrode in a couple of weeks.

Veroboard with alternate strips commoned to each sensor wire?

That was the basis of one in Everyday Electronics which I made
well over 30 years ago. You need to heat it too (a few low power
resistors are sufficient), or it can takes ages to dry out and
stop reportingrain, when therainstopped ages beforehand,
and it might otherwise be triggered by condensation.

I think I've seen a simple module in Maplin which works much
the same way.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]


The only one I could find on MAPLIN was the Velleman MK108 kit ...
http://www.velleman.be/ot/en/product/view/?id=338493

The pdf manual (one page) makes this seem very basic, but has no
details of the sensor, maybe I'm being unfair and the sensor is
sophisticated and does it all .... the circuit seems so simple, that I
would assume buzzer sounds continuously until rain stops ... that is a
bit of a pain.

"Dave Liquorice" wrote in message
ll.net...
On Thu, 28 Aug 2008 20:24:44 +0100, Rick Hughes wrote:

It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

Plenty of kist available try Maplins. As you say the sensor is the biggest
problem. How about a few square inches of veroboard? Give it a rub over
with some fine sand paper to remove the protective lacquer and connect
alternate strips to each sensor wire. Copper will last for ages outside,

I don;t think it will, copper circuit board tracks which is what veroboard
is
tarnish very quickly within weeks. Most circuit boards are coated with a
protective layer to stop this oxidation process.

On Wed, 3 Sep 2008 13:11:16 +0100, whisky-dave wrote:

Give it a rub over with some fine sand paper to remove the protective
lacquer and connect alternate strips to each sensor wire. Copper will
last for ages outside,

I don;t think it will, copper circuit board tracks which is what
veroboard is tarnish very quickly within weeks.

So why is copper still occasionally used as roofing material if it doesn't
last... I don't think copper oxide, or copper salts depending on the
pollution in your area, are insulators unlike say aluminium oxide.

Most circuit boards are coated with a protective layer to stop this
oxidation process.

Main reason is so you don't have to mechanically clean the tracks before
soldering rather than corrosion eating them away. Coatings post assembly
are to stop damp or muck shorting tracks or getting at the board.

--
Cheers
Dave.

In article ,
Osprey writes:
I made the same one ... I even still have that issue of the magazine !

So do I, in that I've never thrown any of them away since 1972.
I have most of the Everyday Electronics up until it stopped,
and then a complete set of Elektor for some years following.
Also much less complete sets of Practical Electronics,
Practical Wireless, and ETI, when they contained something
which grabbed my attention. I haven't routinely bought any for
last 10 years or so now though, but I do regularly design and
build my own electronic projects.

The problem will be long term stability with veroboard in open air ...

The only one I could find on MAPLIN was the Velleman MK108 kit ...
http://www.velleman.be/ot/en/product/view/?id=338493

I recall seeing a built potted module some time back (don't think
it was Velleman). It was quite low power suitable for battery
operation, but had a separate connection for the drying heater,
which made it non-battery suitable if you wanted to use the heater.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In message , Andrew Gabriel
writes
In article ,
Osprey writes:
I made the same one ... I even still have that issue of the magazine !

So do I, in that I've never thrown any of them away since 1972.
I have most of the Everyday Electronics up until it stopped,
and then a complete set of Elektor for some years following.
Also much less complete sets of Practical Electronics,

My collection of PE must date back to the late 60s elektor, ETI, EE and
WW somewhat more sporadic. I still subscribe to E&WW, but I don't think
I'll renew the subscription when it runs out

I think it won't be long until they are all destined for the great skip
in the sky, along with all the IEEE publications etc

Too much 'kin junk !



Practical Wireless, and ETI, when they contained something
which grabbed my attention. I haven't routinely bought any for
last 10 years or so now though, but I do regularly design and
build my own electronic projects.

The problem will be long term stability with veroboard in open air ...

The only one I could find on MAPLIN was the Velleman MK108 kit ...
http://www.velleman.be/ot/en/product/view/?id=338493

I recall seeing a built potted module some time back (don't think
it was Velleman). It was quite low power suitable for battery
operation, but had a separate connection for the drying heater,
which made it non-battery suitable if you wanted to use the heater.


--
geoff

On Thu, 4 Sep 2008 21:57:54 +0100 Geoff wrote :
I think it won't be long until they are all destined for the
great skip in the sky, along with all the IEEE publications etc

And not be able to look back on all the Amstrad ads and the wonders
that once were

"1970 Amstrad's first electrical product, the popular Amstrad 8000
amplifier, priced at pounds 17.70. Sugar says later: "It was the
biggest load of rubbish I've ever seen in my life."

1974 Begins marketing the 6000 and 7000 stereo cassette decks, which
sell well through the new chain of Comet Stores. They include a
"chrome" tape button that is not actually connected to anything.

1976 The EX range of AM/FM tuners, featuring a meter to indicate the
sound quality. In fact they showed perfect sound no matter what the
signal quality."

http://findarticles.com/p/articles/m...0/ai_n14286018

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

OK .. if we are going nostalgic.

I bought my Sinclair Black watch kit from an Add in Practical Electronics -
really cool :-)

I bought an Haversonic stereo amp kit from Practical Electronics ... only
took about 6 months to build and get working, using of course a trusty twin
beam scope and Avo 8.

I buily quite a few variants of John Linley Hood projects .. he was the
manin man of audio designs. (not sure if he is still around)

I have serveral years worth of ETI ... which I thought was the best of the
bunch until it went EPROM & micropocessor based on everything ... so stopped
buying it in mid 80's (is it still going ?)

Watford Electronics was the way of the future - sold everthting !

Have the first few years worth of issues of Everday Electronics, staryting
with issue 1 and free veroboard kit ! .. .still has pack of resistors
stapled to front page !

As somebody else said ... proably time to put them all in recycle bin.

OK ... went to MAPLIN web site they do sell a Velleman water detector kit,
which is totally useless ... it has a simple 2 copper wire detector ... when
it's wet it switches a single transistor to sound a buzzer ....
It will keep sounding untill it dries, which in UK Summer means battery will
not last very long.



Come on guys somebody must know of a better sensor ?


Now if sombdoy knew how to get a car water detector working that may be a
good plan ... I have a glass roof to kitched & conservatory so plenty of
places to put it.

"Rick Hughes" wrote in message
...
OK ... went to MAPLIN web site they do sell a Velleman water detector kit,
which is totally useless ... it has a simple 2 copper wire detector ...
when it's wet it switches a single transistor to sound a buzzer ....
It will keep sounding untill it dries, which in UK Summer means battery
will not last very long.



Come on guys somebody must know of a better sensor ?

I bought a water detector in lidl about five weeks ago, they were ~£5.
Small sensor connected to a battery box with a chime/alarm in it.
I suppose it would make a rain alarm but the surface area is a bit small.
I expect it would work with a strip board wired alternately to increase the
area.
They were also marketed as bath overflow alarms so you may get something
similar in boots.

It would certainly work if you put the sensor in the gutter once the water
reached there.

On 5 Sep, 13:17, "Rick Hughes" wrote:
OK ... went to MAPLIN web site they do sell a Velleman water detector kit,
which is totally useless ... it has a simple 2 copper wire detector ... when
it's wet it switches a single transistor to sound a buzzer ....
It will keep sounding untill it dries, which in UK Summer means battery will
not last very long.

Put a big capacitor in series with the buzzer, then the buzzer will
only sound until the cap charges.

Also put a high value resistor across the capacitor to allow it to
discharge, or it will only work once

cheers,
Pete.

In message , Rick Hughes
writes
OK .. if we are going nostalgic.

I bought my Sinclair Black watch kit from an Add in Practical
Electronics - really cool :-)

I bought an Haversonic stereo amp kit from Practical Electronics ...
only took about 6 months to build and get working, using of course a
trusty twin beam scope and Avo 8.

I buily quite a few variants of John Linley Hood projects .. he was the
manin man of audio designs. (not sure if he is still around)


A legend in his own linear response

I have serveral years worth of ETI ... which I thought was the best of
the bunch until it went EPROM & micropocessor based on everything ...
so stopped buying it in mid 80's (is it still going ?)

Which was different to Tomorrows World at the time, how exactly ?



Watford Electronics was the way of the future - sold everthting !

Cardiff Road was 5 minutes walk - I went past the place a fortnight ago


Have the first few years worth of issues of Everday Electronics,
staryting with issue 1 and free veroboard kit ! .. .still has pack of
resistors stapled to front page !

And the resistor wire bending former, and ...


As somebody else said ... proably time to put them all in recycle bin.

memories, eh ?


--
geoff

"Andrew Gabriel" wrote in message
...

I think I've seen a simple module in Maplin which works much
the same way.

[email address is not usable -- followup in the newsgroup]



Maplin did not have anything other than a simple 2 wire detector - too
insensitive and once wet would continue to 'trigger in UK weather not much
use.

An update ... in case anybody does a similar search in future ... found a
detector module on line ... which has a built in heater to dry it when rain
stops:

http://www.kemo-electronic.com/en/module/m152/index.htm

example of it being used is on

http://www.weather-above.com/Rain%20duration%20complete%20with%20heater.html


an on-line rain detector project is :

http://www.techlib.com/electronics/raindetectors.htm

Invisible Man wrote:
Phil Addison wrote:
On Sun, 31 Aug 2008 08:31:30 +0100, in uk.d-i-y "Donwill" popple
@diddle .dot wrote:

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an
audible signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't
rely on it staying dry long enough to dry kit.


I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ...
large enough surface are to catch first few drops of rain, stable
enough not to corrode in a couple of weeks.
An optical sensor might be better, what do they fit to modern cars
these days? the auto windscreen wiper seemed to work OK on the
Peugeot 807 I used to have .

Yes, wife has a 206 and its auto wiper works well (provided you can
remember the switch flick-sequence to activate it!). And it's inside, so
doesn't get wet. It detects wetness on the other side of the glass.
Could it use a light beam totally reflected at the glass surface, but
passing through when the surface is wet - or the other way round? It has
a very fast response, generates single sweeps in light rain.

Phil

Our Mazda 3 Sport has an optical system. I assume it works on uneven
spread of light when raindrops fall on the outside of the windscreen
where the sensor is on the inside. Trouble is I often drive it in the
dark on unlit roads and if there are not a lot of oncoming headlights it
does not work well enough. My wife tends to use it in daylight and
reckons the system is brilliant.

Optical rain detection systems typically work by launching IR light into the
windscreen.

The light is confined to the windscreen through total internal reflection (TIR)

When there is water present on the windscreen it no longer undergoes TIR,
but is effectively coupled out of the glass, resulting in a drop in the
received signal.

A simple system, the clever parts are establishing the launch and receive
locations such that the system works reliably without lots of unnecessary
triggering.

On coming light should not really be a problem providing the operating
wavelength is well chosen and the receiver appropriately filtered. I would
also assume the light source is modulated at a few kHz, which is a standard
technique to reduce unwanted background levels.

cheers

David

"DM" wrote in message
...

On coming light should not really be a problem providing the operating
wavelength is well chosen and the receiver appropriately filtered. I would
also assume the light source is modulated at a few kHz, which is a
standard technique to reduce unwanted background levels.

Until someone makes an IR transmitter to fit to their car just to turn on
other peoples wipers as they drive around. 8-)

On 1 Sep, 00:41, Phil Addison wrote:
On Sun, 31 Aug 2008 08:31:30 +0100, in uk.d-i-y "Donwill" popple



@diddle .dot wrote:

"Rick Hughes" wrote in message
...
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) and can't rely
on it staying dry long enough to dry kit.

I have found a link to one project
http://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

An optical sensor might be better, what do they fit to modern cars these
days? the auto windscreen wiper seemed to work OK on the Peugeot 807 I used
to have .

Yes, wife has a 206 and its auto wiper works well (provided you can
remember the switch flick-sequence to activate it!). And it's inside, so
doesn't get wet. It detects wetness on the other side of the glass.
Could it use a light beam totally reflected at the glass surface, but
passing through when the surface is wet - or the other way round? It has
a very fast response, generates single sweeps in light rain.

Phil

The 206 one is not bad, but there are times where a manual sensitivity
control would be useful. Some patterns of rain seem to trigger the
unit incorrectly such that you have to do a manual sweep occasionally.
However, if a large drop of rain from a tree or something hits in the
right location you get a single wiper shot to slurp it up. Usually
impresses people.
Simon.

Come on guys somebody must know of a better sensor ?


Now if sombdoy knew how to get a car water detector working that may be a
good plan ... I have a glass roof to kitched & conservatory so plenty of
places to put it.

This link may help,
http://www.fordscorpio.co.uk/autowiper.htm

Don