fluid detector??

has any body got an knowledge of fluid detector and limit switches i-e how they work because i am going to use them as water sensors for my water motor controller project.

silvarblade said:

has any body got an knowledge of fluid detector and limit switches i-e how they work because i am going to use them as water sensors for my water motor controller project.

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Please elaborate on how you want to use them. If you search you will find many circuits and ways of controlling water pumps. One way that I still want to try is to use ultrasonic rangers to measure the water level...

The most common limit switches that I have seen for use in fluids are the simple float switches used in a septic system like the one I have. Sort of like these:

Aquahub Homepage

You calibrate the level at which these switch by hanging them carefully at a specific level. When the fluid exceeds or drops below that level, the switch changes state.

you can use ordinairy float switches (available at every plumbing shop) or make a sort of sensor probe model your self (also comercial availible)

the circuit i post is a fluid level detector and works fine (from experiance)

keep in mind that over the years some corosion will occure on the probes so make something that the probes can be replaced

sucsess

Robert-Jan

Fluid Detector

Maybe it will help!

well i can not access the upper tank cause it is selaed.when it is filled water comes out through a pipe so one knows it has been filled.i intend to use a fluid detector there,another one for the water coming from the main water pipe from the supply system,and one for the level on the ground water tank. following are the conditions:

1)close both the motors if the water from the main line stops.
2)there are two conditions:
2(a)close the upper thank motor only if it fills up and the water level in the bottom tank is lower than the prescribed level.
2(b)close both the tanks if the upper tank is filled and the water level in the bottom tank is on/above the prescribed level.


PS:i intend to use a uc.

can you draw a simple drawing of the phisical tank and the conections and pipe work
According your latest discription i make up its a 2 tank system

please elaborate a bit more

Robert-jan

What is a uc ??

Hi silvarblade,

I just can't imagine a sealed water tank. There has to be at least a vent hole for the air to escape when the tank is filled with water. It shouldn't be a big problem to drill two holes through the lid to extend two thin stainless steel wires into the tank to measure the water level.

You can do the same fitting a dome on top of the tank with a ping pong ball inside a PVC hose which activates a switch if the tank is full to the top. I used that method closing the drainage valve from my garden to the nearby "Khlong" (flood control canal) if the water level in the Khlong is higher than the water level in the garden around the house. To seal the switch from water you can use an ordinary prophylactic or if you can get it use a rubber diaphragm.

Hans

rjvh said:

What is a uc ??

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Hi Robert-jan,

a uc, better µc, is a microcontroller.

Hans

Boncuk said:

Hi silvarblade,

I just can't imagine a sealed water tank. There has to be at least a vent hole for the air to escape when the tank is filled with water. It shouldn't be a big problem to drill two holes through the lid to extend two thin stainless steel wires into the tank to measure the water level.

You can do the same fitting a dome on top of the tank with a ping pong ball inside a PVC hose which activates a switch if the tank is full to the top. I used that method closing the drainage valve from my garden to the nearby "Khlong" (flood control canal) if the water level in the Khlong is higher than the water level in the garden around the house. To seal the switch from water you can use an ordinary prophylactic or if you can get it use a rubber diaphragm.

Hans

Click to expand...

yeah i am going to upload a drawing as soon as possible.there is actually ahole as said before through which a pipe comes out indicatng the tank is full.i will look in to the ping pog ball thing.thanks for the reply.

here is the diagram. it took me pain staking work to build it.!!!

Normaly you would fill the higest tank firts and from there you control the flow down wards

I don't know what the tanks supplying and what the pressure requirements are at which volume

asuming that you don't need a a pressurized sytem from the tanks than use one pump to fill the higest tank you will need only a high level sensor in that tank

instead of a second pump you will use a float valve to fill the lower tank

in case you want to have a fail safe protection than put a solenoid valve extra in the suplyline of the lower tank and control it with a high level sensor in the lower tank

anny problems to excute it like that??

if there anny phisical obstructions please post a photo of it and i might be able to help you out with advise
for sure the system aproach i discribed is cheaper than what you put on paper

Robert-Jan