A 3:8 priority encoder(near the tank) is used to measure the level of water in the tank,then encode it and transmit into the 8:3 decoder, which is  in the housethe highest level upto which water is filled up,that level is only considered by the encoder,and it encodes it. When the water level increases  the water measuring level contacts are short circuited,and current flows to the data pins of the ic.

Truth table

 

Since the conductivity of water is low,so it is not easy for elctrons to cross the water.So multiple wires contacts are used at every contacts so that electrons can pass through water easily.One end of it is connected to vcc and the other to the data bits.since multiple wiresa are used,each wire will be eroded in a less amount,thus increasing its lifetime.

The encoder ic near the tank can also be powered from solar cells or any nearby power source, whichever convinient.

In the reciever part(in home)-

 

In the house, this water level measurement circuit is placed. For input, a mobile charger can be used. The signals are decoded and are send through the leds.since the output is active low, so the leds are placed in reverse direction. The level upto which the water is filled up, is first encoded and then decoded and the consecutive led glows.

Power source-mobile,ipod chargers  can be used for supplying power to the circuit.

Advantage-

The circuit is simple

Due to encoding less amount of wire is required

The 5 wires(Vcc,G,A,B,C) runs from the encoder to decoder.these wires can be passed through a tube or it can be covered by winding it using selu-tape so that ir doesn,t get damage due to rain…

Since it is priority encoder, even if any pin doesn’t work properly, then the encoder considers the next level, and the led below the actual led glows, thus predicting almost near to the actual result.

 

 

 

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Filed Under: Electronic Projects
Tagged With: water level measurement
 

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