Description
ABSTRACT
The first remote controllers were developed in the early 1990s, and the first remotes were connected with wires to devices. Nowadays remotes use infrared control and thus are capable of controlling several things at a time. The remotes are not only used for entertainment, but also for industries, military requirements, and recreation. Infrared remote controls were developed in the late 1970s. These remote controls use infrared light and photo receptors and different light frequencies for different functions. These remotes also use invisible light beams to send signals to electronic devices.
IR remote controls today can control several devices at a time as the working abilities of these remotes is such that a light beam is emitted out by the remote control and is received by a photo transistor. These remotes receive signals and transmit signals to devices via radio waves. These remotes can control several appliances, equipments and gadgets like, radios, TVs, video games, CD/ DVD players, and also applicable in Space.
The system consists of two sections: a transmitter section and the other receiver section. The transmitter section work as a normal remote and the receiver section remains in a stable position, which means, it is connected to any load.
TABLE OF CONTENTS
COVER PAGE
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWELDGEMENT
ABSTRACT
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
- OBJECTIVE OF THE PROJECT
- SIGNIFICANCE OF THE PROJECT
- PROBLEM AND LIMITATION OF THE PROJECT
- SCOPE OF THE PROJECT
- APPLICATION OF THE PROJECT
CHAPTER TWO
LITERATURE REVIEW
- OVERVIEW OF THE PROJECT
- HISTORICAL BACKGROUND OF THE PROJECT
- AN OVERVIEW OF A REMOTE
- REVIEW OF AN INFRARED TECHNOLOGY
CHAPTER THREE
SYSTEM DESIGN
- DESCRIPTION OF THE SYSTEM BUILDING BLOCK
- SYSTEM DESIGN SPECIFICATION
- BLOCK DIAGRAM OF THE SYSTEM
- DESCRIPTION OF THE OVERALL OPERATION OF THE SYSTEM
- LIST AND DESCRIPTION OF THE SYSTEM COMPONENTS
- COMPLETE CIRCUIT DIAGRAM
CHAPTER FOUR
- IMPLEMENTATION, TESTING AND RESULTS
- CONSTRUCTION PROCEDURE AND TESTING
- INSTALLATION OF THE COMPLET DESIGN
- CASING AND PACKAGING
- ASSEMBLING OF SECTIONS
- TESTING OF SYSTEM OPERATION
- PROBLEM ENCOUNTERED
CHAPTER FIVE
- CONCLUSION
- RECOMMENDATION
- REFERENCES
Presented here is a infrared remote controlled timer circuit. The circuit comprises two sections, namely, the transmitter section and the receiver section. Fig. 1 shows the IR transmitter section. The astable multivibrator NE555 (IC1) is used to generate a 10kHz modulated IR signal. The output of IC1 is connected to the base of pnp transistor T1 via resistor R2. Two infrared LEDs (IR1 and IR2) are connected in series between the collector (via resistor R3) and ground. When switch S1 is pressed, the IR LEDs transmit the modulated IR signal of 10-11 kHz. This frequency can be changed with the help of VR1 potmeter.
Infrared Remote Controlled Timer Circuit
Fig. 1: IR transmitter section
In the receiver section shown in Fig. 2, two photodiodes (IR3 and IR4) receive the IR signal transmitted by the IR transmitter. Transistors T2 and T3 amplify the weak signal. The amplified signal is filtered by capacitors C6 and C7. The amplified and filtered signal is now fed to the inverting input pin 2 of op-amp IC2 (IC 741). The output of IC2 is further connected to trigger pin 2 of timer NE555 (IC3) that is used as a monostable multivibrator whose frequency may be varied with the help of potmeter VR3.
Fig. 2: IR receiver section
Circuit operation
When switch S1 of the transmitter is pressed, the modulated IR rays are generated, which are received by photodiodes in the receiver section and amplified by the amplifier circuit. The output of op-amp goes low to trigger the monostable. Then high output at pin 3 of IC3 activates the two changeover relay RL via transistor T3 (BC548) for a preset time.
The on/off time can be set in the timer with the help of VR3 and C10. Switch S2 is used to reset the monostable. If you want to turn the appliance on for a preset time, connect the appliance via relay RL(a). On the other hand, if you want to turn the appliance off for a preset time, connect the appliance via relay RL(b). The timer can be reset by pressing reset switch S2. The circuit works up to 3 metres without using any focusing lens. However, you can increase the operating range by using focusing lens.
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