Electronics › Electronics › explanation of Water level controller cum indicator circuit › Hi Suman, The circuit is
Hi Suman,
The circuit is clear. I understand your concern but it is time taking to re-draw the entire circuit. I will try to explain you the same, refer below circuit.
1. ULN2003 internal circuit diagram is explained in the circuit with pin numbers so open up the datasheet of ULN2003 IC & refer the pin description & pin diagram.
2. Piezo buzzer is nothing but speaker. Check polarity while connecting.
3. Relay switch is pointed in the below diagram.
when ever you feel confused on connections, try refering corresponding data sheet you will get an idea how to connect it.
Approx cost for this project will cost you less than 150 rupees. Post your further doubts.