Creative Design Problem - fish bowl water level
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Posts: 46,084
A resistor in not the correct item you need a pn junction like a
diode. they have a very definite and easily measurable change over
temperature. not to hard to use one to make a thermometer.
alternate methods.
If you have tap water, the resistance is around 100,000 ohms with a 1
cm gap. city water, rain water, tap water will all be very different.
if you are only concerned with full or not full, all you need is one
sensor at one point.
if you want to know full or empty and do not care if it is 99% or 1%
but just 0% or 100% then 2 sensors.
if you have fish, the voltage would bug them and they would change
the water resistance.
another way could be a sonic bounce off the water surface. time
between would offer depth.
Dave
--- In basicstamps@yahoogroups.com, 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?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
diode. they have a very definite and easily measurable change over
temperature. not to hard to use one to make a thermometer.
alternate methods.
If you have tap water, the resistance is around 100,000 ohms with a 1
cm gap. city water, rain water, tap water will all be very different.
if you are only concerned with full or not full, all you need is one
sensor at one point.
if you want to know full or empty and do not care if it is 99% or 1%
but just 0% or 100% then 2 sensors.
if you have fish, the voltage would bug them and they would change
the water resistance.
another way could be a sonic bounce off the water surface. time
between would offer depth.
Dave
--- In basicstamps@yahoogroups.com, 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?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
Comments
microswitch. When the ball floats, the microswitch activates and therefore
the tank is full. This method allows you to place the switch outside the
tank so no special devices are necessary.
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: Dave Mucha [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=haMxZdyHCMuGkcty5muokjVZ6_ZCvx2_i45K3-8A47tilvU5ki6I7x8eVQjpXctksRNklqELFcFutVw]davemucha@j...[/url
Sent: Monday, October 13, 2003 11:13 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Creative Design Problem - fish bowl water
level
A resistor in not the correct item you need a pn junction like a
diode. they have a very definite and easily measurable change over
temperature. not to hard to use one to make a thermometer.
alternate methods.
If you have tap water, the resistance is around 100,000 ohms with a 1
cm gap. city water, rain water, tap water will all be very different.
if you are only concerned with full or not full, all you need is one
sensor at one point.
if you want to know full or empty and do not care if it is 99% or 1%
but just 0% or 100% then 2 sensors.
if you have fish, the voltage would bug them and they would change
the water resistance.
another way could be a sonic bounce off the water surface. time
between would offer depth.
Dave
--- In basicstamps@yahoogroups.com, 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?
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
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water dish, a 55 gallon drum, a bucket, toilet...??????
[noparse][[/noparse]Non-text portions of this message have been removed]
small piece of wood (popsickle stick), and hang it from a wire clip
attached to the bowl top. When the switch and wood floats, the switch
closes.
Dennis
Original Message
From: Jim Forkin [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=dPYbSNJPO98tYDFLwBxmNso0CXMZWisiOP0dFXTbXaswncu4eus25Yo8OufyKYiRr_xQ9ZU]jjf@p...[/url
Sent: Monday, October 13, 2003 1:01 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Re: Creative Design Problem - fish bowl water
level
glue a ping-pong ball to a wire with epoxy and attach the wire to a
microswitch. When the ball floats, the microswitch activates and
therefore the tank is full. This method allows you to place the switch
outside the tank so no special devices are necessary.
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: Dave Mucha [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=fy0ixMUu1-eEd5eQbyI__hsRYSdKEdJPN6ZxKUSH0HusMeWedVd56hjyYGawBAmWFtMmHrxvi4NR8w]davemucha@j...[/url
Sent: Monday, October 13, 2003 11:13 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Creative Design Problem - fish bowl water
level
A resistor in not the correct item you need a pn junction like a diode.
they have a very definite and easily measurable change over temperature.
not to hard to use one to make a thermometer.
alternate methods.
If you have tap water, the resistance is around 100,000 ohms with a 1 cm
gap. city water, rain water, tap water will all be very different.
if you are only concerned with full or not full, all you need is one
sensor at one point.
if you want to know full or empty and do not care if it is 99% or 1%
but just 0% or 100% then 2 sensors.
if you have fish, the voltage would bug them and they would change the
water resistance.
another way could be a sonic bounce off the water surface. time between
would offer depth.
Dave
--- In basicstamps@yahoogroups.com, 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?
>
>
> [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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and Body of the message will be ignored.
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doleary@e... writes:
++++++++++++++++++++++++++++++
Ahhhhh, very good, very simple
++++++++++++++++++++++++++++++++++++++++
A similar idea without the ball is to attach a mercury tilt-switch to
small piece of wood (popsickle stick), and hang it from a wire clip
attached to the bowl top. When the switch and wood floats, the switch
closes.
Dennis
[noparse][[/noparse]Non-text portions of this message have been removed]