Jul 284 min read

Tank Water Flow Alarm using Transistor Done by Vignan's Nirula Students

Updated: Aug 3

Overview

This project, undertaken by Vignan's Nirula ECE students Harshitha, Tulasi and Santhi represents a significant advancement in the tank overflow alarm system is designed to prevent overflows in liquid storage tanks by providing real-time monitoring and alerting capabilities. This system employs sensors to continuously measure the liquid level within the tank, detecting when it approaches or exceeds predetermined thresholds. Upon detecting an imminent overflow condition, the system activates visual and auditory alarms to notify operators, thereby allowing for prompt corrective actions to prevent spillage and potential damage.

Additionally, the system may include features such as automated shutdown mechanisms, remote monitoring capabilities, and integration with other control systems for enhanced operational safety and efficiency. The implementation of such an alarm system is crucial in industries where liquid management is critical, including chemical processing, water treatment, and oil and gas sectors, where overflow incidents can lead to environmental hazards and economic losses.

Steps involved in PCB designing:

1. Design Specification

Requirement Analysis: Define the functional requirements and constraints for the PCB, including size, number of layers, and electrical specifications.
Schematic Design: Create a schematic diagram showing the electrical connections between components using PCB design software.

2. PCB Layout Design

Component Placement: Arrange the components on the PCB layout according to the schematic. Ensure that components are placed for optimal signal flow and ease of routing.
Routing: Connect the components with traces, considering electrical constraints such as trace width and spacing. Use routing tools in the PCB design software to automate or manually route the connections.
Design Rule Check (DRC): Run DRC to verify that the design adheres to manufacturing and electrical specifications.

3. Generating Gerber Files

File Generation: Create Gerber files, which are standard file formats used to describe the PCB layers, drill holes, and other manufacturing details.
Bill of Materials (BoM): Prepare a BoM listing all components and their specifications needed for the PCB assembly.

4. PCB Fabrication

Penalization: Combine multiple PCBs into a single panel for efficient manufacturing.
Layer Printing: Print the copper layers on the PCB substrate using photolithography or other methods.
Etching: Remove unwanted copper from the PCB to create the traces and pads.
Drilling: Drill holes for component leads, vias, and other features.
Plating: Plate the drilled holes with copper to create electrical connections between layers if the PCB is multilayer.
Solder Mask and Silkscreen: Apply a solder mask to protect the traces and a silkscreen layer for component markings.

5. PCB Assembly

Component Placement: Place the components onto the PCB, typically using automated pick-and-place machines.
Soldering: Solder the components to the PCB, which can be done through techniques like wave soldering, reflow soldering, or hand soldering.

6. Testing and Quality Control

Electrical Testing: Perform tests such as in-circuit testing (ICT) or functional testing to ensure the PCB operates as intended.
Inspection: Inspect the PCB visually or using automated optical inspection (AOI) to check for soldering issues or defects.

7. Final Assembly and Packaging

Enclosure: Place the PCB in an enclosure if required.
Final Assembly: Complete any additional assembly tasks, such as attaching connectors, displays, or other peripherals.
Packaging: Package the final product for shipment or distribution.

Required components:

1. Transistor (BC547)

2. Resistor (1k ohm)

3. Buzzer

4. HDR M (1*2) connectors

5. 9v battery

6. JST connectors

7. PCB board

Block Diagram

Fig1: Block Diagram

Transistor BC547:

The BC547 is an NPN transistor, meaning it has a layer of P-type semiconductor material sandwiched between two N-type layers. It is commonly used for low to moderate power amplification and switching applications.

In NPN transistors like the BC547, when a small current flows into the base, it allows a larger current to flow from the collector to the emitter. This characteristic makes it useful for amplification and switching.

Construction and working:

Construction:

Open EASY EDA software and select the components and connect the circuit diagram in below manner. Consider BC547 transistor and connect the emitter of the BC547 to the ground (anode terminal) of the power supply then connect the collector of the BC547 to one terminal of the buzzer. Now another terminal of the buzzer is connected to the positive terminal (Cathode terminal) of the power supply. The base of the transistor is connected to the one terminal of the HDR connector which is placed in the water and another terminal of HDR terminal is connected to the positive terminal of the buzzer.

Fig 2: - Schematic Diagram

After completing the construction of circuit diagram, we have to save it and convert it into the Layout diagram.

Fig 3: - Layout Diagram

Working:

Normal Water Level (Below HDR pin level):

When the water level in the tank is below the HDR terminal in water, the switch remains open.
With the float switch open, there is no current flowing into the base of the BC547 transistor.
Without base current, the BC547 transistor remains in the "off" state.
In the "off" state, there is no current flowing from the collector to the emitter.
Consequently, the buzzer does not receive current and remains silent.

Water Level Reaches Overflow Point (Reached HDR pin level):

When the water level rises to the point where it touches the HDR terminal, the switch closes.
Closing the switch allows current to flow from the positive terminal of the power supply to the base of the BC547 transistor through the base resistor and here water is used as conductor.
This base current turns the BC547 transistor "on," allowing current to flow from the collector to the emitter.
As a result, current flows through the buzzer from the positive terminal of the power supply to ground via the transistor.
The buzzer sounds, providing an alarm to indicate that the tank is at or above the desired level.

Outcome: