Title: Building a Fun and Smart Home with a DIY Smart Doorbell Introduction: In the exciting world of electronics, there's nothing quite as thrilling as creating your very own smart home gadgets. Today, we'll embark on a journey to build a Smart Doorbell using simple and easily accessible equipment like the Arduino Uno, an IR proximity sensor, and a buzzer. This DIY project is not only a fantastic introduction to electronics but also a step towards transforming your home into a tech-savvy haven. So, gear up, young inventors, as we venture into the world of smart homes! Materials You'll Need: 1. Arduino Uno: The brain of our smart doorbell, capable of processing information and controlling the connected devices. 2. IR Proximity Sensor: A nifty gadget that detects the presence of objects in its vicinity. 3. Buzzer: This component will be the voice of our smart doorbell, alerting you when someone approaches. Step 1: Setting Up the Arduino Uno: Begin by connecting your Arduin...
IGNITION SYSTEM
In spark ignition [ S.I.] engines, a device is required to ignite [ set fire to ] the compressed air and fuel mixture at the end of compression stroke. Ignition system fulfills the requirement. It is a part of electrical system which carries the electric current at required voltage to the spark plugs which generates spark at correct time. it consist of;
- battery
- switch
- distributor ignition coil
- spark plug
- contact breaker
- condenser
REQUIREMENT FOR AN IGNITION SYSTEM
- The ignition system should be cable of producing high voltage current, as high as 22,000 volts or more so that spark plug can produce spark across its electrode gap
- It should produce spark for sufficient duration so that mixture [ air and fuel ] can be ignited at all operating speed for automobile
- Spark must generate at current time as the end of the compression stroke in every cycle of engine operation.
- It should be able to function smoothly even when the spark plug electrodes are deposited with carbon and oil.
CONSTRUCTION AND OPERATION
The system employs a 6-12 volt battery for the supply of low tension current. One terminal of the battery is earthed to the frame of the engine, and the other is connected to the primary terminal of the ignition coil through an ammeter or directly to the ignition switch.
The ignition system can be turn on or off with the help of the ignition switch and the switch is place with eazy reach of the driver.
The ignition coil consist of primary and secondary coils wound on a soft iron core. The primary windings has a small number of turns of thick wire and the secondary winding has a large number of turns of thin wire. whereas one terminal of the primary winding connects with the battery, the other terminal is connected to one end of the contact point of the circuit breaker and to one of the close point to the earth.
Apparently, the primary circuit of the ignition coil gets completed when contact point of the circuit breaker are held together and the ignition switch is closed.
The contact breaker is a spring control switch and is operated by means of a cam. The lobes of the cams corresponds to the number of cylinders and for a four stroke cycle engine, the cam is motored at half the engine speed. The contact breaker breaks the primary circuit for each cylinder during one complete cycle of the engine.
A condenser is connected in parallel with the contact breaker unit and it’s function to provide reservoir for current.
Distributor and the spark plugs for a multi-cylinder engine. A high tension cable connects the secondary coil to the distributor, and from the distributor the cables are connected to all the spark plugs.
IGNITION TIMING
Ignition timing is the correct instant of generating spark just before the completion of compression stroke. Correct ignition timing is necessary to maximize power output of an engine
EFFECT OF IGNITION ADVANCE AND IGNITION RETARD
- IGNITION ADVANCE : Ignition advance is the condition where ignition of fuel occurs earlier than the correct timing . Ignition of mixture takes place near the end of compress stroke. If the ignition is advance it means fuel-air mixture will burn too early before the end of compression stroke. In this case, the crank and connecting rod will have to push the piston in order to compress the gases [ for completing the compression stroke. ] In this situation the force applied on piston by the connecting rod in upward direction may not be able to over come the downward force acting on piston. This downward force acting on the piston is due to enormous pressure generated by the combustion of fuel. Under this condition, the engine may stop or stall. Spark advance may also cause the fuel to explode suddenly under certain operating condition
- IGNITION RETARD : Ignition retard means the condition when ignition occurs after the correct ignition timing. It is known that after ignition burning [ combustion ] of fuel takes place if ignition is retarded too much than the combustion of fuel-air mixture [charge] will continue during power stroke. Therefore peak pressures will not be developed consequently work output of the engine will decrease. In this case, burnt gases will leave the engine cylinder at higher temperature which will over heat the exhaust valves. It result in loss of power, over heating and sometimes burning of exhaust valves and excessive carbon deposit.
FIRING ORDER
The sequence in which the power is produced in an engine is called ‘firing order’. Decision of firing order is a part of design to as get best performance.
When the cylinders are in line the cylinder nearest the radiator is designed as number one[1], the one directly behind it is number two[2] and so on. The general firing order of a four cylinder engine is 1-3-4-2. But as it depends on some factors like flywheel mass, unbalanced forces, type of fuel and oil, it can be some other like 1-2-4-3 and 1-5-3-6-2-4 for six[6] cylinder engine.