Course Content

Abstract:
The Wheelchair Fall Detection circuit is designed using a tilt vibration sensor and a comparator IC LM393. The tilt vibration sensor detects sudden changes in orientation or shocks, while the LM393 acts as a comparator. During stable operation, the sensor remains inactive, and the LED stays off. When a fall or significant tilt is detected, the sensor activates, causing the LED to glow, signaling the event.

Application of the Circuit:
This circuit offers a cost-effective solution for wheelchair fall detection, utilizing the tilt vibration sensor for reliable and accurate fall detection. It is ideal for healthcare applications, enhancing safety for the elderly and differently-abled individuals.

Why This Particular Circuit:
Tilt vibration sensors are compact, affordable, and efficient. They operate seamlessly with a 5V DC power supply, making the circuit easy to integrate with USB-powered devices or other standard DC sources.

Explained Working of the Circuit:
The tilt vibration sensor reacts to changes in position, angle, or shocks by generating an electrical signal. The LM393 comparator processes this signal and activates the LED, providing a clear indication of a fall or tilt event. The circuit is simple yet effective, ensuring dependable fall detection.

How to Build:

• Follow the circuit diagram and PCB layout provided in the manual.
• Solder components according to the layout, paying attention to correct positioning and polarity.
• Use IC sockets for easy replacement of the LM393 during troubleshooting.
• Begin soldering from one corner of the PCB and proceed systematically.
• Handle sensitive components, such as diodes and capacitors, with care.

Testing the Kit:
After assembly, connect a 5V DC power supply. Tilt or shake the sensor to simulate a fall or orientation change. The LED should glow when the sensor detects a tilt or vibration. Adjust the R2 variable resistor to fine-tune the sensitivity of the detection.

ICs Used:

• LM393: A dual comparator IC suitable for interpreting tilt or vibration signals.

Part List:

• Semiconductors: LM393 (U1), 8-pin base
• Resistors: R2 – 10k Ohm (variable), R3 – 1k Ohm, R4 – 1k Ohm, R5 – 10k Ohm, R6 – 10k Ohm
• Capacitor: C1 – 1uF
• Miscellaneous: Tilt Vibration Sensor, Red LED (D1), Green LED (D2), 5V USB Cable, PCB

Key Applications:

• Wheelchair fall detection and safety for elderly and differently-abled individuals.
• Healthcare monitoring and mobility assistance devices.
• Orientation and tilt detection in automation and robotics projects.