Creative Design Problem
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I hope some of you bright minds out there can give me a simple and efficient
solution to this design problem:
How can the basic stamp be used to determine whether or not a water bowl is
empty or full?
My first idea was actually to plant a resistor in the bowl. I thought that
when the resistor was dry, it would give a resistance higher than when it was
submerged in water. However, I didnt notice any appreciable difference in
resistance for the two cases. Can anyone think of a better strategy?
[noparse][[/noparse]Non-text portions of this message have been removed]
solution to this design problem:
How can the basic stamp be used to determine whether or not a water bowl is
empty or full?
My first idea was actually to plant a resistor in the bowl. I thought that
when the resistor was dry, it would give a resistance higher than when it was
submerged in water. However, I didnt notice any appreciable difference in
resistance for the two cases. Can anyone think of a better strategy?
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
>I hope some of you bright minds out there can give me a simple and efficient
>solution to this design problem:
>
>How can the basic stamp be used to determine whether or not a water bowl is
>empty or full?
>
>My first idea was actually to plant a resistor in the bowl. I thought that
>when the resistor was dry, it would give a resistance higher than when it was
>submerged in water. However, I didnt notice any appreciable difference in
>resistance for the two cases. Can anyone think of a better strategy?
A float switch of some sort is one approach. Another approach is to measure
the weight of the dish. It will weigh more with water in it than when it's
empty.
A counterbalance arrangement might work well for the weight method rather
than actually measuring the weight of the container with and without water.
Think
seesaw.
Bruce Bates
>[noparse][[/noparse]Non-text portions of this message have been removed]
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a shaft down from the lever into the water with a float on it. As the water
lowers or rises, you'll have an analog value that represents the water level.
pot
O----o swivel joint on lever (I used a thin aluminum strip)
|
| shaft
|
~~~O~~~ water level
float
I did this years ago on a small fish tank, and it worked really well at
reporting
the water level. I used an ADC0831 8-bit A/D converter IC to read the pot. If
the water rose too quickly, I had an alarm go off to scare the cat away from
the fish tank...;o]
Regards,
-Bruce
tech@r...
http://www.rentron.com
Original Message
From: <MP1428@a...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, October 12, 2003 8:55 AM
Subject: [noparse][[/noparse]basicstamps] Creative Design Problem
> I hope some of you bright minds out there can give me a simple and efficient
> solution to this design problem:
>
> How can the basic stamp be used to determine whether or not a water bowl is
> empty or full?
>
> My first idea was actually to plant a resistor in the bowl. I thought that
> when the resistor was dry, it would give a resistance higher than when it was
> submerged in water. However, I didnt notice any appreciable difference in
> resistance for the two cases. Can anyone think of a better strategy?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
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>
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>
>
between empty and full. Perhaps putting one of these Flexiforce
sensors...
http://www.parallax.com/detail.asp?product_id=30056
...under the bowl will be all it takes.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: MP1428@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=fkpgOaerbIb3BbL7gAesae0j1iMwuz5QKE9jddqankfpk0p61xanC6bmEtHZOzvh9A22BQ]MP1428@a...[/url
Sent: Sunday, October 12, 2003 9:55 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Creative Design Problem
I hope some of you bright minds out there can give me a simple and
efficient
solution to this design problem:
How can the basic stamp be used to determine whether or not a water bowl
is
empty or full?
My first idea was actually to plant a resistor in the bowl. I thought
that
when the resistor was dry, it would give a resistance higher than when
it was
submerged in water. However, I didnt notice any appreciable difference
in
resistance for the two cases. Can anyone think of a better strategy?
[noparse][[/noparse]Non-text portions of this message have been removed]
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MP1428@a... writes:
I hope some of you bright minds out there can give me a simple and efficient
solution to this design problem:
How can the basic stamp be used to determine whether or not a water bowl is
empty or full?
My first idea was actually to plant a resistor in the bowl. I thought that
when the resistor was dry, it would give a resistance higher than when it was
submerged in water. However, I didnt notice any appreciable difference in
resistance for the two cases. Can anyone think of a better strategy?
plunger type rod with micro swithes on it a little hot glue and you are in
business very simple in about 20 minutes and very accurate use a wood stick into
the straw a large straw to act as the plunger and cut cams into the stick get a
normally closed switch so when it hits the cut out in the wood stick it opens up
the use a pull up resistor config to work your electronics just brain storming
hope it helps I can cad you a pix if you would like and send it to you.
Bruce Bates <bvbates@u...> wrote:At 10:55 AM 10/12/03 -0400,
MP1428@a... wrote:
>I hope some of you bright minds out there can give me a simple and efficient
>solution to this design problem:
>
>How can the basic stamp be used to determine whether or not a water bowl is
>empty or full?
>
>My first idea was actually to plant a resistor in the bowl. I thought that
>when the resistor was dry, it would give a resistance higher than when it was
>submerged in water. However, I didnt notice any appreciable difference in
>resistance for the two cases. Can anyone think of a better strategy?
A float switch of some sort is one approach. Another approach is to measure
the weight of the dish. It will weigh more with water in it than when it's
empty.
A counterbalance arrangement might work well for the weight method rather
than actually measuring the weight of the container with and without water.
Think
seesaw.
Bruce Bates
>[noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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>
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I would loop some clear plastic tubing so it looks like a little open ended
barometer and shoot an LED/phototransistor through the tubing as a detector.
If you align the pair at something other than perpendicular to the tubing,
I would postulate there would be enough diffraction change when water is
between the sensors to misalign the beam. Of course, the
plastic of the pipe needs to be transparent to the light frequency of the
LED emitter.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "frog28043" <frog28043@y...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, October 12, 2003 9:14 PM
Subject: Re: [noparse][[/noparse]basicstamps] Creative Design Problem
> use a tube like a straw in the water the water level will rise you could
use a plunger type rod with micro swithes on it a little hot glue and you
are in business very simple in about 20 minutes and very accurate use a wood
stick into the straw a large straw to act as the plunger and cut cams into
the stick get a normally closed switch so when it hits the cut out in the
wood stick it opens up the use a pull up resistor config to work your
electronics just brain storming hope it helps I can cad you a pix if you
would like and send it to you.
>
> Bruce Bates <bvbates@u...> wrote:At 10:55 AM 10/12/03 -0400,
MP1428@a... wrote:
> >I hope some of you bright minds out there can give me a simple and
efficient
> >solution to this design problem:
> >
> >How can the basic stamp be used to determine whether or not a water bowl
is
> >empty or full?
> >
> >My first idea was actually to plant a resistor in the bowl. I thought
that
> >when the resistor was dry, it would give a resistance higher than when it
was
> >submerged in water. However, I didnt notice any appreciable difference in
> >resistance for the two cases. Can anyone think of a better strategy?
>
> A float switch of some sort is one approach. Another approach is to
measure
> the weight of the dish. It will weigh more with water in it than when it's
> empty.
> A counterbalance arrangement might work well for the weight method rather
> than actually measuring the weight of the container with and without
water.
> Think
> seesaw.
>
> Bruce Bates
>
>
>
>
> >[noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> >from the same email address that you subscribed. Text in the Subject and
> >Body of the message will be ignored.
> >
> >
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>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
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>
>
>
>
>
> Do you Yahoo!?
> The New Yahoo! Shopping - with improved product search
>
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>
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>
>
On Sun, 12 Oct 2003, smartdim@a... wrote:
> In a message dated 10/12/2003 7:56:20 AM Pacific Daylight Time,
> MP1428@a... writes:
> I hope some of you bright minds out there can give me a simple and efficient
> solution to this design problem:
>
> How can the basic stamp be used to determine whether or not a water bowl is
> empty or full?
>
> My first idea was actually to plant a resistor in the bowl. I thought that
> when the resistor was dry, it would give a resistance higher than when it was
> submerged in water. However, I didnt notice any appreciable difference in
> resistance for the two cases. Can anyone think of a better strategy?
>
purchased one from parallax (inexpensive !!! $15). Not real happy with the
hysterisis of the sensor and therefore not able to use it as I originally
wanted,
but from data I took from the FLEXIFORCE sensor looks like the simplest
solution to the sensing the water level.
Ken
_______________________________________________
In a message dated 10/13/2003 12:40:15 PM Pacific Daylight Time,
lamont@a... writes:
Float switch?
On Sun, 12 Oct 2003, smartdim@a... wrote:
> In a message dated 10/12/2003 7:56:20 AM Pacific Daylight Time,
> MP1428@a... writes:
> I hope some of you bright minds out there can give me a simple and efficient
> solution to this design problem:
>
> How can the basic stamp be used to determine whether or not a water bowl is
> empty or full?
>
> My first idea was actually to plant a resistor in the bowl. I thought that
> when the resistor was dry, it would give a resistance higher than when it
was
> submerged in water. However, I didnt notice any appreciable difference in
> resistance for the two cases. Can anyone think of a better strategy?
>
attached to a lever, lever attached to a potentiometer. when the ping pong
rises it will give you a digital value utilizing RCTIME. this way you may
monitor where the water level is. you can determine whether its full 1/4
full 1/8 full and so on. this is a precise measurement method. you could
probably attach the lever easily to a 10 K ohm pot and then use Silicon or
power seal to attach the lever to the ping pong ball. hope this might give
you an idea.
At 12:39 PM 10/13/2003 -0700, you wrote:
>Float switch?
>
>On Sun, 12 Oct 2003, smartdim@a... wrote:
>
> > In a message dated 10/12/2003 7:56:20 AM Pacific Daylight Time,
> > MP1428@a... writes:
> > I hope some of you bright minds out there can give me a simple and
> efficient
> > solution to this design problem:
> >
> > How can the basic stamp be used to determine whether or not a water bowl is
> > empty or full?
> >
> > My first idea was actually to plant a resistor in the bowl. I thought that
> > when the resistor was dry, it would give a resistance higher than when
> it was
> > submerged in water. However, I didnt notice any appreciable difference in
> > resistance for the two cases. Can anyone think of a better strategy?
> >
>