Automotive electronics



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AUTOMOTIVE ELECTRONICS
UNIT-1
Section-A
1. How Engine Works?
It's the reason you can put the pedal to the metal and go from zero to 60 in about 8 seconds. The car engine is a piece of engineering genius and one of the most amazing machines we use on a daily basis.
2. How Diesel Engine Works?
Diesels are more efficient and cheaper to run than gasoline engines. Instead of using carburetion or port fuel injection, diesel engines use direct fuel injection.
3.How Rotator Engine Works?
A rotary engine is an internal combustion engine, but it's not like the one in most cars. Also called a Winkle engine, this type of engine performs intake, compression, combustion and exhaust in a different part of the housing.
4. How Quarsiturbine Engine Works?
The quasiturbine engine takes the Wankel concept and improves on it: Instead of three combustion chambers, it has four, and the setup of a quasiturbine allows for continual combustion. That means greater efficiency than any other engine in its class.
5.How Super Charger Works?
Since the invention of the internal combustion engine, automotive engineers, speed junkies and racecar designers have been searching for ways to boost its power. One way is by installing a supercharger, which forces more air into the combustion chamber
Section-B

1.Explain the Operation of Current in ACH?


ACH currently operates the following plants:

Indianapolis Plant--Indianapolis, Indiana (steering components): Ford has extended the life of this plant to the end of 2011.

Milan Plant--Milan, Michigan: The Milan plant produces gas tanks, and in the past has produced bumper fascias.

Saline Plant--Saline, Michigan: The Saline plant produces interior components including instrument panels, consoles and door trim.

Sandusky Plant--Sandusky, Ohio: Lighting/air induction/fuel vapor storage production.

Sheldon Road Plant--Plymouth, Michigan: Climate control components.

2. How does automotive multiplex systems work?

Each of the systems (ABS, Engine, Airbag ect) has a control unit. Each of these control units has a transmitter and a receiver to "talk" to the other units. The units are "ranked" according to safety or the systems that they control. As an example, this is how the system would operate. The ABS system receives a message fom the wheel sensors to say that the wheels have locked. The ABS unit sends a message to the engine unit to reduce throttle angle (acceleration). At this point, the ABS unit has priority to send messages. The vehicle fails to stop and crashes. At this point the airbag (SRS) unit sends out a crash signal. Now, the SRS unit has priority, as it is safety crittical.

3. what is Versatile system infrastructure?


The OCS has abstracted major objects of all charging processes as the pillars of its infrastructure and adopts customer-oriented design ideas. It is based on a model that separates subscribers from accounts as well as features an off-the-shelf product management mode. It completely breaks away from the traditional offline hard coding development mode based on service flow. This leads to a stable but versatile system infrastructure, which enables online tariff configurations through rule-driven engine technology, and the product launch period is greatly shortened.

4. Explain about Unified charging engine for all services


The traditional IN provides real-time charging & rating capabilities only to prepaid subscribers. The traditional billing system is always offline based on CDR file processing. It handles non real-time charging requirements, and its charging execution process is not directly involved in service application control. The OCS is oriented to all subscriber types and service types, offers unified online charging and online control capabilities and can be used as a unified charging engine for all network services, making it a core basis for convergent billing in the network.

5. Explain Briefly about Rapidly boosted marketing capabilities


Both the traditional IN and the billing system are somewhat passive support systems for market promotion with the limited charging capabilities.

The OCS offers unprecedented flexibility and extendibility, or you could say, gives the ball to the marketing department to run with it. With the OCS, the marketing department can really explore network resource potentials and the desires of subscribers, to create personalized and feasible promotion strategies that meet the marketing objectives.



Section-C

1. Explain about Air-start system


An air-start system is a power source used to provide the initial rotation to start large diesel and gas turbine engines.

Compared to a gasoline ("petrol") engine, diesel engines have very high compression ratios to provide for reliable and complete ignition of the fuel without spark plugs. An electric starter powerful enough to turn a large diesel engine would itself be so large as to be impractical, thus the need for an alternative system. When starting the engine, compressed air is admitted to whichever cylinder has a piston just over top dead center, forcing it downward. As the engine starts to turn, the air-start valve on the next cylinder in line opens to continue the rotation. As this goes on, fuel is injected into the cylinders, the engine is then under way and the air is cut off. To further complicate matters, a large engine is usually "blown over" first with zero fuel settings and the indicator cocks open, to prove that the engine is clear of any water build up and that everything is free to turn. After a successful blow ahead and a blow astern, the indicator cocks are closed on all the cylinders, and then the engine can be started on fuel. Significant complexity is added to the engine by using an air-start system, as the cylinder head must have an extra valve in each cylinder to admit the air in for starting, plus the required control systems. This added complexity and cost limits the use of air-starters to very large and expensive reciprocating engines.





Cutaway of an air-start system of a General Electric J79 turbojet. The small turbine (next to yellow shaft) and epicyclic gearing (to right of perforated metal screen) are clearly visible.

Another method of air-starting an internal combustion engine is by using compressed air or gas to drive a fluid motor in place of an electric motor. They can be used to start engines from 5 to 320 liters in size and if more starting power is necessary two or more motors can be used. Starters of this type are used in place of electric motors because of their lighter weight and higher reliability. They can also outlast an electric starter by a factor of three and are easier to rebuild.

An air-starter on a turbine engine would typically consist of a radial inward flow turbine, or axial flow turbine, which is connected to the High Pressure compressor spool through the accessory gearbox, plus the associated piping and valves. Compressed air is provided to the system by bleed air from the aircraft's auxiliary power unit or from an air compressor mounted on ground support equipment.

Compared to electric starters, air-starters have a higher power-to-weight ratio. Electric starters and their wiring can become excessively hot if it takes longer than expected to start the engine, while air-starters can be run as long as their air supply lasts. Turbine starters are much simpler and are a natural fit for turbine engines, and thus are used extensively on large turbofan engines used on commercial and military aircraft.

The air starter industry has been known to be extremely competitive thus creating questionable, and unscrupulous behavior among many suppliers.




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