Light Sensors:

Light sensors provide a sensitive measurement of light and are often used as non-intrusive motion sensors. Typical light sensors include photodiodes, phototransistors, photoresistors, infrared detectors, etc. Example project ideas:

• Devise an experiment to validate the inverse square law of light decay.
• Determine the effectiveness of different light insulating materials and light reflecting materials.
• Develop prototype systems such as home/office theft alarm, marine collision detection, and automated door opener, etc., using a light sensor and an appropriate logic algorithm.

Sound Sensor:

A sound sensor measures the fluctuation in air pressure to provide a measure of amplitude and frequency of sound waves. Example projrct ideas:

• Perform noise pollution studies in the proximity of busy streets, train tracks, airports, etc.
• Determine the effectiveness of different materials in absorbing sound of different amplitude/frequency.
• Demonstrate the feasibility of destructive interference techniques for noise cancellation.

Thermal Sensors:

A thermal sensor measures the fluctuation of either temperature or heat flux in different media. Typical thermal sensors include thermistors, resistance temperature devices (RTDs), thermocouples, thermopiles, etc. Example project ideas:

• Design a prototype experiment, using an air and a carbon dioxide filled enclosure, a lamp, and temperature sensors, to validate the phenomenon of global warming.
• Design an experiment to validate Newton's Law of Cooling, which states that the rate of heat transfer from a hot to cold body is proportional to their temperature difference.
• Using heat flux and temperature sensors distributed throughout the interior and exterior of a house, which is subjected to extreme exterior weather conditions, measure the heat loss from specific locations of the house and recommend appropriate action.

Feedback Control:

In feedback control, the error between desired output and actual output of a system is used to compute and apply a corrective action. Example project ideas:

• Develop an automatic liquid dispensing machine, which begins dispensing liquid once a cup is placed on it and stops when the liquid level in the cup is about to violate safety limit.
• Develop a prototype automatic headlight control system for automobiles, which turns the light on/off by continuously monitoring the ambient light condition.
• Develop an indoor climate control system, which controls heating and air conditioning units to maintain a comfortable environment.
• Develop a prototype device to control indoor lights when window blinds are opened/closed.

Voltage Divider:

Numerous sensor designs exploit the "Voltage Division Law" to provide the measurement of a physical quantity by measuring the voltage across a resistor. Example project ideas:

• Develop a comprehensive fault detection system for automobiles using the voltage divider circuit and appropriate resistive sensors. For example:
  • Using a resistive temperature sensor, monitor the engine temperature.
  • Using a resistive pressure sensor, monitor the air pressure in tires and pressure in hydraulic lines of a braking system.
  • Using a thermistor, develop a sensor to warn the driver of icy road condition.
• Develop subsystems for home monitoring/automation that exploit the voltage divider circuit and appropriate resistive sensors. For example:
  • Monitoring the ambient light intensity to turn on (off) the lights at sunset (sunrise)
  • Monitoring the activities of inhabitants in a house to control heating/cooling systems
  • Monitoring unauthorized entry in the house