Water Level Alarm [dirt Cheap!][no Circuits]

Most of us may have been scolded badly for leaving the water pump on for too long and causing over-flow in our over head tanks.
the water level indicators in the market are pretty expensive and unnecessary most of the times.

I tried making one myself with stuff lying around in the house.

Step 1: Materials Needed

hmmm.. this section is extremely flexible depending on your improvisations.

1. small plastic bottle with cap - 1 (50-100ml)
2. single strand wires. - 30cm + 2 x (distance from tank to your room)
3. aluminum sheet - about 5 x 2 cm
( salvage from a coke can)
4. strip of hard plastic - 30cm (or just 15cm if u r imitating my design)
u can cut away from some box like i  did.
5. gel pen refill - 1
6. batteries/ dry cells - 2
7. switch - 1 (optional)
8. a tweeter or an electric bell

tools-
1. one ruler
2. pliers
3. plastic adhesive. (avoid using cyanoacrylate if possible)
4. soldering iron and its cronies :-P
5. a cutter or small hacksaw

Step 2: Making the Parts

the alarm has three parts

1. the level sensor
2. the indicator.
3. you!

a) the lever

if you see the image, you'll realise what i have done.
take a strip of hard plastic measuring about 15 cm.
mark a line at 5cm from one end.
heat at the line till soft and slowly bend till perpendicular.
OR cut and paste at 90 degrees.

b) the float.
use the plastic bottle!!
stick it at the longer end. make sure the bottle will remain watertight by gluing or using a sealant in the bottle cap and screw it in.

Step 3: The Support Frame

if using plastic strip, bend to same shape as shown.
 i used a steel bicycle spoke.
just bend it like shown.
dimensions are:
 20mm X 20mm at the hinge
70 mm at the body.
10mm x 20mm at the hook
the frame is 20mm wide.

now slit a piece of refill and insert it at the hinge.
[ tip - make sure you scratch the surfaces where you'll be applying adhesive. in this case, the refill.]

IF you made a wire frame like me, you shud cover it up.
i used a strip of plastic lying around. make sure its not flabby or easily bend-able.

Step 4: Assemble

prepare contact points-

cut the aluminum strip into two pieces of atleast 10mm x 30mm

bend the strip into a curve as shown.

solder one end of wire to each curved strip of aluminum
[P.S-  I'm using aluminum b'coz of other metals forming a corroded film due to moisture in the water tank.]

if u wanna avoid soldering like me,
- make a slit in aluminum. insert the wire and press the aluminum over it. it'll hold well.
 (but frankly, i'm not sure about the life of this type of contacts. especially taking the electrode potential into consideration.)

get the adhesive ready.

stick one aluminum contact strip to the small end of the lever.
stick the lever arm at the bend to the slit refill.
stick another Al contact strip on the support frame such that the strip on lever will touch it when lifted to close position.

now run the wires towards the hook so that they dont hinder the movement of the lever.

your sensor is ready. test contacts

Step 5: Atach to Tank and Jhakaas!

once making sure of the contacts working well, attach the sensor from the hook in the tank at a level you want to be warned at.
make sure the sensor doesnot get submerged. only the bottle should be in contact with water when tank is full.

lead the wire out of tank and into your house to a point where you desire the alarm/ indicator.

attach the battery/ dry cells, switch, tweeter/ electric bell in series and complete the circuit.

Now, you can forget looking at the clock everytime the pump is on and let the alarm do the work!!