Contactless Breaking System

Contactless Breaking System Using IR Sensor Module & Relay Module

1. Introduction

In this project, we have designed a Contactless Breaking System utilizing an IR sensor module and a relay module. The primary objective is to create a system that can automatically stop a motor when an object (in this case, a human hand) comes near the IR sensor. The system operates on a 7.4V DC supply, powered by two 18650 batteries connected in series to deliver 3.7V each. The IR sensor detects the proximity of a hand, generating a logic signal that controls the relay, which, in turn, powers off the motor.

2. Project Components

The project uses the following key components:

1. IR Sensor Module: The IR sensor detects objects by emitting infrared light and receiving it through the photodetector. When a hand or object comes within range of the sensor, it sends a signal indicating proximity.
2. Relay Module: The relay module is responsible for controlling the motor. When it receives the logic low signal from the IR sensor, it activates to cut off the motor’s power.
3. 18650 Li-ion Batteries: These rechargeable batteries are connected in series to power the circuit. With each battery providing 3.7V, two batteries supply a total of 7.4V.
4. Motor: A DC motor is used in the project. The motor is powered by the relay module, and it stops when the relay turns off.

3. Working Principle

The working principle of the system is straightforward:

• The IR sensor module continuously emits infrared light and detects any object or hand that interrupts the emitted light.
• When a hand (or object) is detected within the sensor’s range, the sensor generates a logic low (0V) signal.
• This signal is then sent to the relay module, which activates or turns on the relay to break the power supply to the motor, effectively stopping it.
• The motor remains off until the object (hand) is removed, and the IR sensor again detects the absence of the object, causing the relay to reset and the motor to resume operation.

4. Circuit Design

The circuit design consists of the following components:

1. IR Sensor Module: The IR sensor module connects to the relay module through GPIO pins (input and output). The IR sensor detects the proximity of a hand and sends a low logic signal to the relay module.
2. Relay Module: The relay is a switch that controls the motor. The relay has two states:
   • Normally open (NO): The contacts are open and no current flows to the motor.
   • Closed (when activated): The relay closes the circuit, and power is supplied to the motor, turning it on.
3. Motor: The motor is connected to the relay’s output side, ensuring that it will only run when the relay closes the circuit.
4. Power Supply: The 7.4V DC supply powers the entire circuit, with two 18650 batteries connected in series to provide the required voltage.

5. System Flow

1. The system starts with the IR sensor constantly scanning for any changes in proximity.
2. When the user places their hand near the sensor, the IR sensor generates a logic low signal.
3. This logic low signal is transmitted to the relay module, which then activates.
4. The relay, when activated, breaks the connection to the motor and turns it off.
5. When the hand is removed, the sensor detects no interruption in the infrared beam, and the logic state becomes high.
6. The relay module resets, and the motor is powered on again.

6. Power Consumption

The system operates with a 7.4V DC supply. The power consumption is primarily determined by the current drawn by the IR sensor, relay module, and motor. The 18650 Li-ion batteries are a practical solution for portable applications, providing a significant energy source with rechargeable capabilities. The estimated total current consumption should be minimal, except when the motor is running, which would cause an increased load on the power supply.

7. Advantages of the System

• Contactless Operation: The system eliminates the need for physical interaction to turn the motor on or off, improving convenience and hygiene, especially in environments where manual contact should be avoided.
• Energy Efficiency: The system uses minimal energy, and the use of rechargeable 18650 Li-ion batteries makes it cost-effective and environmentally friendly.
• Safety: By automatically stopping the motor when a hand comes near the sensor, the system can enhance safety by preventing potential injuries.
• Simple Circuit Design: The system involves straightforward components, making it easy to implement and modify for various applications.

8. Challenges & Limitations

• Sensor Range: The range of the IR sensor can be limited, requiring calibration to ensure proper functionality at the intended distance.
• Environmental Interference: Strong light sources or reflective surfaces could potentially interfere with the IR sensor, causing false readings or delayed response times.
• Power Consumption: The motor’s power consumption is the highest in the system, which may require more frequent charging or larger battery packs for extended operation.

9. Conclusion

This contactless breaking system using the IR sensor and relay module offers a convenient, safe, and efficient way to control a motor. It works by detecting a hand or object near the sensor, and upon detection, it stops the motor via the relay module. The use of 18650 batteries ensures a portable and eco-friendly solution for this system. While there are some challenges with sensor range and environmental factors, the overall design provides a functional and reliable contactless control system for motors.

10. Future Improvements

• Enhance Sensor Range: Future versions of the system can use more advanced IR sensors with a longer range to increase its operational flexibility.
• Advanced Relay Control: Incorporating additional relay functions or switching capabilities could offer better control over more complex motor setups.
• Integration with Wireless Systems: Adding wireless communication features (e.g., Bluetooth or Wi-Fi) could allow remote control and monitoring of the system.

This system can be used in various applications, such as in automatic doors, contactless switches for appliances, and industrial machines requiring remote control without physical interaction.