03-01-2013, 11:09 AM
TEMPERATURE CONTROLLED FAN
TEMPERATURE CONTROLLED FAN.docx (Size: 77.99 KB / Downloads: 84)
INTRODUCTION
Over the last decade, advances in digital electronics have made computer smaller, cheaper and faster. Throughout this revolution as well, mobile computing environment such as PDA has been created and undoubtedly other advances in technology like smart home also play an important role towards better life in the future. This project is about how we can control the fan based on temperature sensor regardless of traditional thermostat. It is also part of smart home application where the fan will gradually increase the speed if the temperature in the environment is increasing. Besides that, the component
that made up the temperature sensor is known as thermistor. A sensor is a type of transducer. In a broader sense, a transducer is sometimes defined as any device that converts energy from one form to another. There are two types of thermistor depend on the sign of k. Firstly is positive temperature coefficient (PTC). PTC thermistor works by increasing the resistance with increasing temperature. Secondly is negative temperature coefficient (NTC). NTC thermistor works by decreasing the resistance with increasing temperature. This project will focus on NTC type of thermistor. Experiment can be followed to evaluate whether this circuit can save energy through the use of temperature sensor and thus promote efficiency. Finally, after some experiments have done, the result of the experimentation and finding can be concluded.
WHAT IS TEMPERATURE CONTROL?
Temperature is the physical property of a system which underlies the common notions of "hot" and "cold"; the material with the higher temperature is said to be hotter. Temperature is a measure of the average kinetic energy of the particles in a sample of matter. In other words, temperature is a measure of activity and the frequency of collisions of molecules.
The formal properties of temperature are studied in thermodynamics. Formally, temperature is that property which governs the transfer of thermal energy, or heat, between one system and another. When two systems are at the same temperature, they are
in thermal equilibrium and no heat transfer will occur. When a temperature difference does exist, heat will tend to move from the higher-temperature system to the lower temperature system, until thermal equilibrium is established. This heat transfer may occur
via conduction, convection or radiation. Temperature is related to the amount of thermal energy or heat in a system. As more heat is added the temperature rises, similarly a decrease in temperature corresponds to a loss of heat from the system. On the microscopic scale this heat corresponds to the random motion of atoms and molecules in the system. Thus, an increase in temperature corresponds in an increase in the rate of movement of the atoms in the system.
WHAT IS TEMPERATURE CONTROLLED FAN?
In brief, temperature controlled fan is an alternative way to deal with the speed of the motor. Temperature control is a process in which the temperature of an object is measured and the passage of heat energy into or out of the object is adjusted to achieve a desired temperature.
A thermostat is a simple example for a closed control loop. It constantly measures the current temperature and controls the heater's valve setting to increase or decrease the room temperature according the user-defined setting. A simple method switches the heater or cooler either completely on, or completely off, and an overshoot and undershoot of the controlled temperature must be expected.
PROJECT DESCRIPTION:
This circuit purpose is to control the speed of a fan related to temperature with a minimum parts counting and avoiding the use of special-purpose ICs, often difficult to obtain.