Today we are going to demonstrate a very useful project of a Wireless water level indicator circuit. This circuit will detect the water level for different containers and act as an alarm. One of the best features of this circuit is that it will detect the selected level of water and inform you wirelessly to a long-distance range by transmitting a melody on your FM radio.
It is an ideal device if you want to monitor the water level even from a distance.
Hardware Components
The following components are required to make Wireless Water Level Indicator Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Battery | 3.7V | 1 |
| 2. | Probes- | – | 2 |
| 3. | Transistor | BC547, 2N3904 | 1, 1 |
| 4. | IC | UM66 | 1 |
| 5. | Variable resistor | 50K, 10K | 1, 1 |
| 6. | Ceramic Capacitor | 0.1uF, 28pF, 2pF, 5pF, 62pF, 10nF, 1N | 1, 1, 1, 1, 1, 1, 1, 1 |
| 7. | Resistor | 39KΩ, 100Ω | 1, 1 |
| 8. | Antenna | – | 1 |
BC547 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BC547
Wireless Water Level Indicator Circuit
Working Explanation
This circuit is operating at 3.6V. We are using a melody generator IC UM66 which is connected to an FM transmitter circuit to transmit the melody to the FM receiver. The volume of the melody is adjusted by a 10K variable resistor.
Water is detected by probes when it reaches the desired level it starts conducting electricity and sends the signal to a transistor which activates and turns on the UM66 IC. It generates a melody which is then transmitted through the FM transmitter circuit. The transmitting frequency is adjusted by TR which is a 1-30pF trimmer capacitor. The antenna should be any 12-inch wire or 30-inch wire if you want maximum range. The coil L1 is equal to 2 turns of # 24 wire wound on 5mm form (remove the form after winding the coil).
Circuit tuning
Connect the power and put probes in water or use a 100Ω resistor between them to activate the transistor. This will activate the IC and the transmitter circuit, now tune your FM receiver on a blank dial and adjust the trimmer capacitor until you listen to a melody. Tune the circuit from a distance of 10 meters to make sure you’ve turned a real frequency not harmonics.
Applications and Uses
- Water tanks
- Swimming pools
- Washing machines
- Aquariums
