> On 4/9/06, Bob Axtell <spam_OUTengineerTakeThisOuTcotse.net> wrote:
>  
>> My wife bought a ceramic fountain. It has a pump that draws water
>> from the bottom and pumps it to the top, so the birds can bathe in it
>> and it srips down to the bottom again. Looks neat, works nice, kills
>> some of the road noise.
>>
>> The problem is that in So Arizona, the water evaporates so fast, I
>> can't discipline myself to keep it filled. So... I am gonna design a
>> slick way to sense when the water level is low so it can kick on a
>> solenoid and pump some back into it. I don't want to use anything
>> ugly, or big (like a float valve). I had in mind a  non-contact sensor,
>> perhaps a capacitor. The whole sensor/solenoid deal could then
>> be automatic.
>>
>> What would work reliably? I am leaning toward a probe with two
>> insulated contacts, that I can make part of a tuned circuit; when
>> the water is missing between the probes, the frequency is at a
>> certain range, with the water between the probes, the frequency
>> is detuned. Another idea was to mount a  tiny magnetic float  in
>> a plastic tube, and when the  float  is high enough, it triggers a
>> hall device.
>>
>> Any other ideas?
>>    
>
> A fountain automation it can't be without a PIC. Telemetry, ultrasonic
> range finder, laser beams...using top DSP or ARM cores...
> :)
> Maybe a simple mercury sealed switch (floating on the water surface)
> connected directly (or using a relay) into your low power pump circuit
> ? No PIC, allowing a long distance to pump and safe histeresys. The
> smallest I've seen looks like a watch bulb.
>
>  
>>    
>
>  

> OK, here is the design:
>
> At the Fountain:
>
> 1. At the fountain is a white plumbing pipe, very thin wall. This one has a
> water connection (ribbed stub) on the side and has an open top and bottom.
> It is the water filling method, and doubles as the water sensor as well.
> This looks to be a standard plumbing fixture, cost about $1 USD.
>
> 2. The outside of the thin wall pipe has 4 "plates" of copper adhesive foil,
> rectangles, two above the other two. These plates do NOT contact each other
> and are 2"x W by 2" high. There should be a 1/10" gap between the
> plates. Small
> insulated wires  are soldered to the plates, going up on the outside of
> the plates
> to the top of the pipe.
>
>  3. Craft stores here in the Colonies named Michael's sell a two-part
> clear epoxy
> that hardens rock hard. A batch should be made up and the lower part of
> the pipe,
> including all of the copper, should be dipped several times until it has
> a coating of
> about 1-1.5mm of plastic. Allow this to harden for 24 hrs. You can now
> run tests
> on the water sensor, if you like. NO conductor touches the water, EVER.
>
> 4. The water sensor is composed of the 4 plates of the water pipe. The
> lower two
> plates are to be tied (1) to a PIC input and (2) to PIC GND . The upper
> two plates
> are tied to another PIC input and also to PIC GND. The upper plates are
> the reference
> capacitor and the lower plates are the sensor capacitor.
>
> 5. Water in the fountain floods the lower set of plates , INSIDE the
> pipe.  This dramatically
> increases the capacitance of the lower "capacitance". The water does NOT
> reach the  upper
> plates, which act as a reference; because the "PIC" input capacitor
> measuring method is subject
> to temperature variants, the fact that both caps are measured allows us
> to make a more reliable
> judgment. The ratio of ACTIVE count to REF count is about 4:1 with water
> detected. Our water
> is pretty ho-hum, has a little magnesium and a little chlorine.
>
> 6. At the top of the pipe is a PIC10F200 on a 1/4" x 1/2" PCB encased in
> plastic epoxy. The
> PIC, when powered, makes several capacitor measurements by HOW MANY TEST
> LOOPS
> are needed before the capacitor no longer holds a charge. The PIC will
> make 16 passes for
> each capacitor, then send back both averages to the main control unit.
> The data is sent back
> using Manchester code, with a bit time of approx 5mS/bit. The data
> stream is two '1' start
> bits, followed by 8 REFERENCE data bits, followed by 8 SENSOR data bits,
> followed by a
> dummy STOP bit. This keeps repeating as long as it is powered. So the
> decision about the
> water level is decided AWAY from the water.
>
> The Controller to Fountain Cable:      
>
> 1. The water sensor itself needs 5V, GND, and an output signal, so a
> cable of 4 conductors is
> used, GND is doubled and the cable is shielded. This will be about 25'
> (7m) long.
>
> 2. The water pump needs AC mains (here 115VAC 60Hz 30w).
>
> These two cables will be enclosed into a waterproof outdoor conduit.
> This will be buried 12"
> down.
>
> Note: there will be a water hose as well; I am using flexible hose
> enclosed by neoprene split
> hose, and also buried at 12". The neoprene will prevent the other hose
> from being closed by
> the weight of the soil above it. The hose can be quite small; I am using
> 1/4" hose. This keeps
> the fountain filled with water.
>
> Controller:
>
> 1. Mounted on the side of the house is a small waterproof NEMA box
> containing electronics
> and controls. A small waterproof PB switch, GREEN/RED LED,  and
> photodiode is mounted
> on the outside.
>
> 2. Two 30A 12V relays operate the PUMP and the WATER SOLENOID. While
> neither of
> these draw 30A, a larger contact area in general means a longer life.
> Internally the 115VAC
> mains is protected by an internal 1A "slowblow" fuse.
>
> 3. A internal PCB contains the following:  a PIC12F675  DIP (socketed) ,
> the two 12V relays,
> a 12V & 5V power supply for  the PCB and fountain sensor, a photodiode
> (for sensing daylight),
> and a couple of cables & connectors.
>
> 4. Action: (A) the fountain does NOT pump during the night, as the
> photodiode detects no daylight.
> But during the night, every 15 minutes, the water sensor turns on and
> the water level is determined.
> If water is needed, the sensor is turned off and the water flows for
> about one minute. This cycle repeats
> all night.
>
> 5. Action: (B) during the day, the fountain pumps. Every 5 minutes, the
> water sensor turns on and the
> water level is determined; if water is needed, the sensor is turned off,
> water is turned on for one minute.
> The reason to do this more often is that during the day, evaporation is
> MUCH higher.
>
> 6. The RED LED will wink if both sensors appear to be identical; this
> might indicate that the water has
> run totally dry; this will also cause the pump to shut off.
>
> 7. Normally operation is automatic; if the switch is pressed, whatever
> is happening will stop for one hour.
> For example, if the pump was running normally, it will now STOP. If it
> was previously stopped manually,
> it will now start running again. This is normally used to allow the user
> to clean bird feathers out of the
> fountain.
>
> - - -
>
> Flames expected.
>
> --Bob
>
>
>
> Vasile Surducan wrote:
>  
>> On 4/9/06, Bob Axtell <.....engineerKILLspam@spam@cotse.net> wrote:
>>  
>>    
>>> My wife bought a ceramic fountain. It has a pump that draws water
>>> from the bottom and pumps it to the top, so the birds can bathe in it
>>> and it srips down to the bottom again. Looks neat, works nice, kills
>>> some of the road noise.
>>>
>>> The problem is that in So Arizona, the water evaporates so fast, I
>>> can't discipline myself to keep it filled. So... I am gonna design a
>>> slick way to sense when the water level is low so it can kick on a
>>> solenoid and pump some back into it. I don't want to use anything
>>> ugly, or big (like a float valve). I had in mind a  non-contact sensor,
>>> perhaps a capacitor. The whole sensor/solenoid deal could then
>>> be automatic.
>>>
>>> What would work reliably? I am leaning toward a probe with two
>>> insulated contacts, that I can make part of a tuned circuit; when
>>> the water is missing between the probes, the frequency is at a
>>> certain range, with the water between the probes, the frequency
>>> is detuned. Another idea was to mount a  tiny magnetic float  in
>>> a plastic tube, and when the  float  is high enough, it triggers a
>>> hall device.
>>>
>>> Any other ideas?
>>>    
>>>      
>> A fountain automation it can't be without a PIC. Telemetry, ultrasonic
>> range finder, laser beams...using top DSP or ARM cores...
>> :)
>> Maybe a simple mercury sealed switch (floating on the water surface)
>> connected directly (or using a relay) into your low power pump circuit
>> ? No PIC, allowing a long distance to pump and safe histeresys. The
>> smallest I've seen looks like a watch bulb.
>>
>>  
>>    
>>>    
>>>      
>>  
>>    
>
>  

>
> At the Fountain:
>
> 1. At the fountain is a white plumbing pipe, very thin wall. This one has a
> water connection (ribbed stub) on the side and has an open top and bottom.
> It is the water filling method, and doubles as the water sensor as well.
> This looks to be a standard plumbing fixture, cost about $1 USD.
>
> 2. The outside of the thin wall pipe has 4 "plates" of copper adhesive foil,
> rectangles, two above the other two. These plates do NOT contact each other
> and are 2"x W by 2" high. There should be a 1/10" gap between the
> plates. Small
> insulated wires  are soldered to the plates, going up on the outside of
> the plates
> to the top of the pipe.
>
>  3. Craft stores here in the Colonies named Michael's sell a two-part
> clear epoxy
> that hardens rock hard. A batch should be made up and the lower part of
> the pipe,
> including all of the copper, should be dipped several times until it has
> a coating of
> about 1-1.5mm of plastic. Allow this to harden for 24 hrs. You can now
> run tests
> on the water sensor, if you like. NO conductor touches the water, EVER.
>
> 4. The water sensor is composed of the 4 plates of the water pipe. The
> lower two
> plates are to be tied (1) to a PIC input and (2) to PIC GND . The upper
> two plates
> are tied to another PIC input and also to PIC GND. The upper plates are
> the reference
> capacitor and the lower plates are the sensor capacitor.
>
> 5. Water in the fountain floods the lower set of plates , INSIDE the
> pipe.  This dramatically
> increases the capacitance of the lower "capacitance". The water does NOT
> reach the  upper
> plates, which act as a reference; because the "PIC" input capacitor
> measuring method is subject
> to temperature variants, the fact that both caps are measured allows us
> to make a more reliable
> judgment. The ratio of ACTIVE count to REF count is about 4:1 with water
> detected. Our water
> is pretty ho-hum, has a little magnesium and a little chlorine.
>
> 6. At the top of the pipe is a PIC10F200 on a 1/4" x 1/2" PCB encased in
> plastic epoxy. The
> PIC, when powered, makes several capacitor measurements by HOW MANY TEST
> LOOPS
> are needed before the capacitor no longer holds a charge. The PIC will
> make 16 passes for
> each capacitor, then send back both averages to the main control unit.
> The data is sent back
> using Manchester code, with a bit time of approx 5mS/bit. The data
> stream is two '1' start
> bits, followed by 8 REFERENCE data bits, followed by 8 SENSOR data bits,
> followed by a
> dummy STOP bit. This keeps repeating as long as it is powered. So the
> decision about the
> water level is decided AWAY from the water.
>
> The Controller to Fountain Cable:
>
> 1. The water sensor itself needs 5V, GND, and an output signal, so a
> cable of 4 conductors is
> used, GND is doubled and the cable is shielded. This will be about 25'
> (7m) long.
>
> 2. The water pump needs AC mains (here 115VAC 60Hz 30w).
>
> These two cables will be enclosed into a waterproof outdoor conduit.
> This will be buried 12"
> down.
>
> Note: there will be a water hose as well; I am using flexible hose
> enclosed by neoprene split
> hose, and also buried at 12". The neoprene will prevent the other hose
> from being closed by
> the weight of the soil above it. The hose can be quite small; I am using
> 1/4" hose. This keeps
> the fountain filled with water.
>
> Controller:
>
> 1. Mounted on the side of the house is a small waterproof NEMA box
> containing electronics
> and controls. A small waterproof PB switch, GREEN/RED LED,  and
> photodiode is mounted
> on the outside.
>
> 2. Two 30A 12V relays operate the PUMP and the WATER SOLENOID. While
> neither of
> these draw 30A, a larger contact area in general means a longer life.
> Internally the 115VAC
> mains is protected by an internal 1A "slowblow" fuse.
>
> 3. A internal PCB contains the following:  a PIC12F675  DIP (socketed) ,
> the two 12V relays,
> a 12V & 5V power supply for  the PCB and fountain sensor, a photodiode
> (for sensing daylight),
> and a couple of cables & connectors.
>
> 4. Action: (A) the fountain does NOT pump during the night, as the
> photodiode detects no daylight.
> But during the night, every 15 minutes, the water sensor turns on and
> the water level is determined.
> If water is needed, the sensor is turned off and the water flows for
> about one minute. This cycle repeats
> all night.
>
> 5. Action: (B) during the day, the fountain pumps. Every 5 minutes, the
> water sensor turns on and the
> water level is determined; if water is needed, the sensor is turned off,
> water is turned on for one minute.
> The reason to do this more often is that during the day, evaporation is
> MUCH higher.
>
> 6. The RED LED will wink if both sensors appear to be identical; this
> might indicate that the water has
> run totally dry; this will also cause the pump to shut off.
>
> 7. Normally operation is automatic; if the switch is pressed, whatever
> is happening will stop for one hour.
> For example, if the pump was running normally, it will now STOP. If it
> was previously stopped manually,
> it will now start running again. This is normally used to allow the user
> to clean bird feathers out of the
> fountain.
>
> - - -
>
> Flames expected.
>
> --Bob
>
>
>
> Vasile Surducan wrote:
> > On 4/9/06, Bob Axtell <.....engineerKILLspam.....cotse.net> wrote:
> >
> >> My wife bought a ceramic fountain. It has a pump that draws water
> >> from the bottom and pumps it to the top, so the birds can bathe in it
> >> and it srips down to the bottom again. Looks neat, works nice, kills
> >> some of the road noise.
> >>
> >> The problem is that in So Arizona, the water evaporates so fast, I
> >> can't discipline myself to keep it filled. So... I am gonna design a
> >> slick way to sense when the water level is low so it can kick on a
> >> solenoid and pump some back into it. I don't want to use anything
> >> ugly, or big (like a float valve). I had in mind a  non-contact sensor,
> >> perhaps a capacitor. The whole sensor/solenoid deal could then
> >> be automatic.
> >>
> >> What would work reliably? I am leaning toward a probe with two
> >> insulated contacts, that I can make part of a tuned circuit; when
> >> the water is missing between the probes, the frequency is at a
> >> certain range, with the water between the probes, the frequency
> >> is detuned. Another idea was to mount a  tiny magnetic float  in
> >> a plastic tube, and when the  float  is high enough, it triggers a
> >> hall device.
> >>
> >> Any other ideas?
> >>
> >
> > A fountain automation it can't be without a PIC. Telemetry, ultrasonic
> > range finder, laser beams...using top DSP or ARM cores...
> > :)
> > Maybe a simple mercury sealed switch (floating on the water surface)
> > connected directly (or using a relay) into your low power pump circuit
> > ? No PIC, allowing a long distance to pump and safe histeresys. The
> > smallest I've seen looks like a watch bulb.
> >
> >
> >>
> >
> >
>

> On 4/15/06, Bob Axtell <EraseMEengineerspam_OUTTakeThisOuTcotse.net> wrote:
>  
>> OK, here is the design:
>>    
>
> Very nice design Bob !
>
> Now the problem could be if indeed your wife will be happy with this.
> You said it's her fountain (or just her ideea), and maybe she expects
> manually water fill by your hands, as a loving prove. Wifes behaviour
> is quite unexpected sometimes...
> I hope she will be extremely satisfied by your project, as we are.
> :)
>
> greetings,
> Vasile
>
>  
>> At the Fountain:
>>
>> 1. At the fountain is a white plumbing pipe, very thin wall. This one has a
>> water connection (ribbed stub) on the side and has an open top and bottom.
>> It is the water filling method, and doubles as the water sensor as well.
>> This looks to be a standard plumbing fixture, cost about $1 USD.
>>
>> 2. The outside of the thin wall pipe has 4 "plates" of copper adhesive foil,
>> rectangles, two above the other two. These plates do NOT contact each other
>> and are 2"x W by 2" high. There should be a 1/10" gap between the
>> plates. Small
>> insulated wires  are soldered to the plates, going up on the outside of
>> the plates
>> to the top of the pipe.
>>
>>  3. Craft stores here in the Colonies named Michael's sell a two-part
>> clear epoxy
>> that hardens rock hard. A batch should be made up and the lower part of
>> the pipe,
>> including all of the copper, should be dipped several times until it has
>> a coating of
>> about 1-1.5mm of plastic. Allow this to harden for 24 hrs. You can now
>> run tests
>> on the water sensor, if you like. NO conductor touches the water, EVER.
>>
>> 4. The water sensor is composed of the 4 plates of the water pipe. The
>> lower two
>> plates are to be tied (1) to a PIC input and (2) to PIC GND . The upper
>> two plates
>> are tied to another PIC input and also to PIC GND. The upper plates are
>> the reference
>> capacitor and the lower plates are the sensor capacitor.
>>
>> 5. Water in the fountain floods the lower set of plates , INSIDE the
>> pipe.  This dramatically
>> increases the capacitance of the lower "capacitance". The water does NOT
>> reach the  upper
>> plates, which act as a reference; because the "PIC" input capacitor
>> measuring method is subject
>> to temperature variants, the fact that both caps are measured allows us
>> to make a more reliable
>> judgment. The ratio of ACTIVE count to REF count is about 4:1 with water
>> detected. Our water
>> is pretty ho-hum, has a little magnesium and a little chlorine.
>>
>> 6. At the top of the pipe is a PIC10F200 on a 1/4" x 1/2" PCB encased in
>> plastic epoxy. The
>> PIC, when powered, makes several capacitor measurements by HOW MANY TEST
>> LOOPS
>> are needed before the capacitor no longer holds a charge. The PIC will
>> make 16 passes for
>> each capacitor, then send back both averages to the main control unit.
>> The data is sent back
>> using Manchester code, with a bit time of approx 5mS/bit. The data
>> stream is two '1' start
>> bits, followed by 8 REFERENCE data bits, followed by 8 SENSOR data bits,
>> followed by a
>> dummy STOP bit. This keeps repeating as long as it is powered. So the
>> decision about the
>> water level is decided AWAY from the water.
>>
>> The Controller to Fountain Cable:
>>
>> 1. The water sensor itself needs 5V, GND, and an output signal, so a
>> cable of 4 conductors is
>> used, GND is doubled and the cable is shielded. This will be about 25'
>> (7m) long.
>>
>> 2. The water pump needs AC mains (here 115VAC 60Hz 30w).
>>
>> These two cables will be enclosed into a waterproof outdoor conduit.
>> This will be buried 12"
>> down.
>>
>> Note: there will be a water hose as well; I am using flexible hose
>> enclosed by neoprene split
>> hose, and also buried at 12". The neoprene will prevent the other hose
>> from being closed by
>> the weight of the soil above it. The hose can be quite small; I am using
>> 1/4" hose. This keeps
>> the fountain filled with water.
>>
>> Controller:
>>
>> 1. Mounted on the side of the house is a small waterproof NEMA box
>> containing electronics
>> and controls. A small waterproof PB switch, GREEN/RED LED,  and
>> photodiode is mounted
>> on the outside.
>>
>> 2. Two 30A 12V relays operate the PUMP and the WATER SOLENOID. While
>> neither of
>> these draw 30A, a larger contact area in general means a longer life.
>> Internally the 115VAC
>> mains is protected by an internal 1A "slowblow" fuse.
>>
>> 3. A internal PCB contains the following:  a PIC12F675  DIP (socketed) ,
>> the two 12V relays,
>> a 12V & 5V power supply for  the PCB and fountain sensor, a photodiode
>> (for sensing daylight),
>> and a couple of cables & connectors.
>>
>> 4. Action: (A) the fountain does NOT pump during the night, as the
>> photodiode detects no daylight.
>> But during the night, every 15 minutes, the water sensor turns on and
>> the water level is determined.
>> If water is needed, the sensor is turned off and the water flows for
>> about one minute. This cycle repeats
>> all night.
>>
>> 5. Action: (B) during the day, the fountain pumps. Every 5 minutes, the
>> water sensor turns on and the
>> water level is determined; if water is needed, the sensor is turned off,
>> water is turned on for one minute.
>> The reason to do this more often is that during the day, evaporation is
>> MUCH higher.
>>
>> 6. The RED LED will wink if both sensors appear to be identical; this
>> might indicate that the water has
>> run totally dry; this will also cause the pump to shut off.
>>
>> 7. Normally operation is automatic; if the switch is pressed, whatever
>> is happening will stop for one hour.
>> For example, if the pump was running normally, it will now STOP. If it
>> was previously stopped manually,
>> it will now start running again. This is normally used to allow the user
>> to clean bird feathers out of the
>> fountain.
>>
>> - - -
>>
>> Flames expected.
>>
>> --Bob
>>
>>
>>
>> Vasile Surducan wrote:
>>    
>>> On 4/9/06, Bob Axtell <engineerspam_OUTcotse.net> wrote:
>>>
>>>      
>>>> My wife bought a ceramic fountain. It has a pump that draws water
>>>> from the bottom and pumps it to the top, so the birds can bathe in it
>>>> and it srips down to the bottom again. Looks neat, works nice, kills
>>>> some of the road noise.
>>>>
>>>> The problem is that in So Arizona, the water evaporates so fast, I
>>>> can't discipline myself to keep it filled. So... I am gonna design a
>>>> slick way to sense when the water level is low so it can kick on a
>>>> solenoid and pump some back into it. I don't want to use anything
>>>> ugly, or big (like a float valve). I had in mind a  non-contact sensor,
>>>> perhaps a capacitor. The whole sensor/solenoid deal could then
>>>> be automatic.
>>>>
>>>> What would work reliably? I am leaning toward a probe with two
>>>> insulated contacts, that I can make part of a tuned circuit; when
>>>> the water is missing between the probes, the frequency is at a
>>>> certain range, with the water between the probes, the frequency
>>>> is detuned. Another idea was to mount a  tiny magnetic float  in
>>>> a plastic tube, and when the  float  is high enough, it triggers a
>>>> hall device.
>>>>
>>>> Any other ideas?
>>>>
>>>>        
>>> A fountain automation it can't be without a PIC. Telemetry, ultrasonic
>>> range finder, laser beams...using top DSP or ARM cores...
>>> :)
>>> Maybe a simple mercury sealed switch (floating on the water surface)
>>> connected directly (or using a relay) into your low power pump circuit
>>> ? No PIC, allowing a long distance to pump and safe histeresys. The
>>> smallest I've seen looks like a watch bulb.
>>>
>>>
>>>      
>>>