OCCUPANCY AND TEMPERATURE BASED FAN CONTROLLER

SUBMITTED BY:SHARAFAT HUSSAINANURAG MISHRAVINAY KUMAR MISHRA

UNDER THE GUIDANCE OF Mrs. VANDANA CHAUHANPROJECT COORDINATORMr. PRAVEEN KUMAR

OVERVIEW

This project is used to regulate the fan speed based on number of occupant and turn the fan off when the temperature is below the set temperature .A bulb is also provided with the circuit, it turns on when the number of occupant is greater than zero.

The complete project is divided into three PCB 1. Temperature controller circuit2. Timer and counter circuit3. Speed regulator circuit

We will describe each with block diagram, description of components and circuit diagram

PCB NO.1Temperature controller circuit

Components

1. AT89C52 Microcontroller --12. ADC0804 LCN --13. Temperature Sensor LM35--14. 16*2 LCD Display --15. Voltage Regulator L7805 --16. Resistors --97. Capacitors --58. Diodes --3 9. Transistor TIP120 --210. Crystal Oscillator 12MHz --111. Electric Fan 12 V --112. DC6V RELAY --113. LED --214. BUTTONS --4

PCB-1BLOCK DIAGRAM-1

PCB-1WORKING

HOW DO TEMPERATURE CONTROLLERS WORK?

To accurately control process temperature without extensive operator involvement, a temperature control system relies upon a controller, which accepts a temperature sensor LM35 as input. It compares the actual temperature to the desired control temperature, or set point, and provides an output to a control element. The controller is one part of the entire control system, and the whole system should be analyzed in selecting the proper controller.

ON/OFF CONTROL

An on-off controller is the simplest form of temperature control device. The output from the device is either on or off, with no middle state. An on-off controller will switch the output only when the temperature crosses the set point. For heating control, the output is on when the temperature is below the set point, and off above set point. Since the temperature crosses the set point to change the output state, the process temperature will be cycling continually, going from below set point to above, and back below.For the circuit to turn off or on a electronic DC6V relays is used.

PCB-1DESPRIPTION OF COMPONENTS

ADC0804

FEATURES• 80C48 and 80C80/85 Bus Compatible - No Interfacing Logic Required• Conversion Time . . . . . . . . . . . . . . <100μs• Easy Interface to Most Microprocessors• Will Operate in a “Stand Alone” Mode• Differential Analog Voltage Inputs• Works with Bandgap Voltage References• TTL Compatible Inputs and Outputs• On-Chip Clock Generator• Analog Voltage Input Range (Single + 5V Supply) . . . . . . . 0V to 5V• No Zero-Adjust Required• 80C48 and 80C80/85 Bus Compatible - No Interfacing Logic Required

TEMPERATURE SENSOR LM35The LM35 series are precision integrated circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature.

LM35 INTERFACING WITH ADC0804 LM35

MICROCONTROLLERThe AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory.

POWER SUPPLYFULL WAVE RECTIFIER

INTERFACING THE LCD WITH THE MICROCONTROLLERS

INTERFACING OF A ADC0804 WITH A 8051 MICROCONTROLLER

CIRCUIT DIAGRAM-1

PCB NO.2COUNTER AND TIMER CIRCUIT

COMPONENTS1. IR Transmitter Module 2. IR Receiver Module 3. IC 5554. Up down Counter5. Seven Segment Display6. Seven Segment decoder7. 4 Bit Comparator8. Relay

PCB-2BLOCK DIAGRAM

WORKING OF PCB-2Infrared receiver module is used to receive the infrared signal transmitted by transmitter. In this project we use two infra red sensors. Both connected in the door. Two photodiode’s are also connected to the receiver circuit to detect the infra red signal. Both the infra red sensor is connected to the IC 555 as a monostable timer In attach with the sensor and 555 we use one up down counter circuit. Up down counter increment and decrement the input pulses and display it on the seven segment display. One logic circuit to compare the total number of person in the room is also involved in this project. For this purpose we use ic 7485 4 bit binary comparator to compare the total number of person in the room. One relay driver circuit to interface the main lights or fan with this unit. Relay provide a high voltage to the fan and lights for proper working

PCB-2DESPRIPTION OF COMPONENTS

INFRA RED SENSOR

IC 555The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator and as a flip-flop element. Derivatives provide up to four timing circuits in one package. In this circuit it works as monostable.

MONOSTABLE MODE

In this mode, the 555 functions as a "one-shot" pulse generator

IC 555

UP/DOWN COUNTERA counter that can change state in either direction, under the control of an up/down selector input, is known as an up/down counter. When the selector is in the up state, the counter increments its value. When the selector is in the down state, the counter decrements the count.

IC555 WITH 74192PIN CONFIGURATION

7447 WITH SSD

PCB-2CIRCUIT DIAGRAM

PCB-3SPEED REGULATOR CIRCUIT

In this project we have used a DC6V Motor, in order to control its speed based on the number of occupants, We change the armature current by changing the armature voltage. The up/down counter in PCB-2 is connected to a 4-bit magnitude comparator and in turn connected to a another a-bit comparator. It compare the counter values a gives voltage to ic358 accordingly.

COMPONENTS

1. 7485 Magnitude comparator2. 358 dual op-amp3. Transistor4. Resistors5. LED6. Capacitors

BLOCK DIAGRAM OF PCB-3

DESPRIPTION OF COMPONENTS 7485 Magnitude Comparator

DESCRIPTIONThe 74F85 is a 4-bit magnitude comparator that can be expanded to almost any length. It compares two 4-bit binary, BCD, or other monotonic codes and presents the three possible magnitude results at the outputs. The 4-bit inputs are weighted (A0–A3) and (B0–B3) where A3 and B3 are the most significant bits.

OP-AMP ICFeatures1. Available in 8-Bump micro SMD chip sized

package,2. Internally frequency compensated for

unity gain3. Large dc voltage gain: 100 dB4. Wide bandwidth (unity gain): 1 MHz

(temperature compensated)5. Wide power supply range: Single

supply:3V to 32V:dual supplies:±1.5V to ±16V

6. Very low supply current drain (500 μA)essentially independent of supply

7. Low input offset voltage: 2 mV8. Input common-mode voltage range

includes ground9. Differential input voltage range equal to

the power supply voltage10. Large output voltage swing

PCB-3CIRCUIT DIAGRAM

THANK YOU

“There is neither this world nor the world beyond nor happiness for the one who

doubts.” -BHAGAVAD GITA