The final circuit diagram and design can be seen above. We also thanks to our sponsor JLCPCB(https://jlcpcb.com/RTA) for sponsoring us PCB for this project.
Thanks To JLCPCB. $2 for 1-4 Layer PCBs.
Get SMT Coupons - https://jlcpcb.com/RTA
Component List -
- LED – 5mm
- Resistor – 1 KΩ
- Transistor – BC 547
- Power Source – DC 12v
- Soldering Iron
- Cutting Plus
Water Level Indicator Circuit Design
The schematic of water level indicator circuit along with the PCB layout can be seen above. Here LED and buzzer used to watch and hear the signal of water level. Power supply don’t included with the circuit. You can use any DC 12v adapter or 12v battery.
Transistor Pin Out
We know that, there are two type of transistor. Every transistor contain 3 legs and this 3 legs have different names. Here BC547 is an NPN transistor and if we count it’s leg from left side, then 1st leg “Collector” 2nd leg “Collector” and 3rd leg “Emitter”
Connect LED Lights
To make this water level indicator we are using 5mm LED lights. Here 5 led should be 5 different color. We connect all LED positive leg with DC 12v positive cable and connect LED negative cable with resistors.
We are using 1 KΩ resistor to make this circuit. We connect resistor one terminal with “Collector” leg of transistor and resistor other terminal with negative leg of LED lights.
For alert signal, we are using a buzzer. When the water tank will full, then the buzzer will make sound and let you know that the tank is almost full with water. We connect buzzer positive leg with LED positive leg and buzzer negative leg with resistor.
Now we connect transistor with the circuit. We connect 5 piece BC547 transistor with the circuit. We connect all transistor “Emitter” leg with negative leg of DC 12v power supply.
Our circuit is now ready for use.
Soldering And Cleaning
Neat and perfect soldering is an important part of all kind of PCBs. Since soldering, you should remember that, there should not be any kind of short circuit. After soldering all leg, we cut-off the extra leg of all electronics component.
Our circuit, is now completely ready for use. Now we just connect power supply with the circuit.
Put every transistor “Base” leg inside water tank and check the circuit. Again thanks to JLCPCB for best quality PCBs.