Hello,
How to build ? mean to say what to choose for sensing the level of water in tank rather than using ultrasonic and current sensing probes in tank.
Thats main solution i am searching m it should look good not just a wires ..!
after that i will build a control box which will control pump motor according to level of motor!

Thanks

 

A simple table tennis ball in a tube, with photo cells at different levels will do, or a resistance strip ,do you want to sense if its empty and full only?

 

Hello,
How build this tennis ball in tube??

 

How height of the water tank?
Do you to sense the different water level?
Maybe you could describe more clearly then it will help to solve your problem.

You may check this first -- uln2004-water-level-indicator.

 

There are a number of ways to go about it. A float mechanically driving a LVDT is one way. Depends on the tank size and what you want to spend? A better project description would help!

A common method can be seen here. Tank gets low add water tank gets full remove water? I would use a pressure transducer and measure the pressure which is directly proportional to the level of the water in the tank. Even a small 8 pin uC could run the whole show.Not that a uC is needed, the thing could also run on discreet components, again, what exactly do you want to accomplish?

Ron

 

harvest a float arm from a toilet, mount it on a potentiometer.

 

RRITESH,
People are looking for details. How deep is the water level when full? Do you want to maintain one level...full? Or do you want two levels...full and empty.
Scott,
DC driven electrodes in that circuit will corrode. AC driven ones are better for long term submersion.

Ken

 

harvest a float arm from a toilet, mount it on a potentiometer.

Harvest a pressure switch from an old washing machine. Then modify it for your tank level.

Find a toilet tank pressure type fill valve, like one of these.

Ah, the possibilities are endless. Actually one of our toilets uses one of those pressure valves which is adjustable. I put that thing in the toilet 25 plus years ago and it has outlasted all the other toilet valves in this house combined.

Ron

 

If it is simple fixed level you want to detect then it is easy to make one based on the aquarium level style, a simple reed switch would be in the tube and a float with a magnet around the tube.
http://www.amazon.com/Aquarium-Water-Control-Plastic-Switch/dp/B005FDT02Q
You can also buy the industrial strength variation of it.
Max.

 

RRITESH,
People are looking for details. How deep is the water level when full? Do you want to maintain one level...full? Or do you want two levels...full and empty.
Scott,
DC driven electrodes in that circuit will corrode. AC driven ones are better for long term submersion.

Ken

Thanks for your comment.
If you mean that DC circuit for this thread, it just offering an idea to let him to think of, I think the TS may not have a good idea, so he asked for help.
If you talking about the page that I linked, I didn't thinking too much at that time and I just modified the circuit to suit what the TS asked for help.

 

I was referring to the linked schematic. But we still lack specific info from the "TS"(?).

Ken

 

I was referring to the linked schematic. But we still lack specific info from the "TS"(?).

Ken

The situation are the same in other forums or in Taiwan ...

 

Hang a rod in the tank, and measure its apparent weight with a load cell. The higher the liquid goes, the lighter the rod will seem to be.

 

Hello,
Thanks for super idea of ULN2004 Any way what is the use of diode at same net connecting?
OK, Actually i will build a tank water pump on/off which will sense the level and display in led only 4 level but the water pump motor will work on empty to full only sense as if(0000) turn on switch through relay , if(1111) turn off switch of motor.
i was thinking to have some good sort of viewing rod on plastic or wooden rod so, it can read through it!!

 

What is diffrence between uln2003 and 2804

 

What is diffrence between uln2003 and 2804

Applications include relay
drivers, hammer drivers, lamp drivers, display drivers (LED and gas discharge), line drivers, and logic buffers.
For 100-V (otherwise interchangeable) versions of the ULN2003A and ULN2004A, see the SN75468 and
SN75469, respectively.

The ULN2002A is designed specifically for use with 14-V to 25-V PMOS devices. Each input of this device has a
Zener diode and resistor in series to control the input current to a safe limit. The ULN2003A and ULQ2003A have
a 2.7-kΩ series base resistor for each Darlington pair for operation directly with TTL or 5-V CMOS devices. The
ULN2004A and ULQ2004A have a 10.5-kΩ series base resistor to allow operation directly from CMOS devices
that use supply voltages of 6 V to 15 V. The required input current of the ULN/ULQ2004A is below that of the
ULN/ULQ2003A, and the required voltage is less than that required by the ULN2002A.

The main difference is the internal base resistor. The ULN2003 is designed to be used with TTL (5 Volt) logic inputs. This makes it useful for directly connecting to many micro-controllers. Looking at the design with probes in the tank there is, depending on water purity, a good possibility the probes will corrode quickly and need frequent cleaning.

Ron

 

What is diffrence between uln2003 and 2804

7 darling drivers and 8 darling drivers.

 

7 darling drivers and 8 darling drivers.

Scott, I thought they were all 7 darlington drivers:

Description
The ULN2001, ULN2002, ULN2003 and ULN
2004 are high voltage, high current Darlington
arrays each containing seven open collector
Darlington pairs with common emitters. Each
channel rated at 500 mA and can withstand peak
currents of 600 mA. Suppression diodes are
included for inductive load driving and the inputs
are pinned opposite the outputs to simplify board
layout.
The versions interface to all common logic
families:
– ULN2001 (general purpose, DTL, TTL,
PMOS, CMOS)
– ULN2002 (14 - 25 V PMOS)
– ULN2003 (5 V TTL, CMOS)
– ULN2004 (6 - 15 V CMOS, PMOS)

I thought this "What is difference between uln2003 and 2804" was a typo where he referenced the 2804? y bad on that note.

Ron

 

Scott, I thought they were all 7 darlington drivers:

I thought this "What is difference between uln2003 and 2804" was a typo where he referenced the 2804? y bad on that note.
Ron

ULN2804 - 8 darlington drivers.

 

ULN2804 - 8 darlington drivers.

Yeah, I read the data sheet, my bad.

Ron