18-01-2012, 03:11 PM
TEMPERATURE BASED FAN SPEED CONTROLLER
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Existing Model
At present we use voltage regulators which are used manually to alter the speed of a fan .
MICROCONTROLLER
-The AT89S52 is a 40 pin microcontroller.
-Mainly microcontroller is based on single task.
-Microcontroller is famous because of
Interrupts
Timers/counters
Serial communication
ADC 0808
-The ADC0808 data acquisition component is a monolithic CMOS device with an 8-bit analog-to-digital converter, 8-channel multiplexer and microprocessor compatible control logic.
-The ADC0808 offers high speed, high accuracy, minimal temperature dependence, excellent long-term accuracy and repeatability, and consumes minimal power
LM 35 TEMPERATURE SENSOR
The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is
linearly proportional to the Celsius
(Centigrade) temperature.
Features
Calibrated directly in ° Celsius
(Centigrade)
Linear + 10.0 mV/°C scale factor
Rated for full −55° to +150°C range
Suitable for remote applications
Low cost
Operates from 4 to 30 volts
