NEWSLETTER FROM RAJESH JOSHI INSPIRATION 11th

January 2012

Electrical Technology for Automobiles

When Allesandro Volta, an Italian physicist, invented the

storage battery in 1796, he had no idea that he was

invented the modern automotive electrical system. Volta

made his discovery 89 years before the first car was put on

sale. It took another 25 year for automakers to even take

notice. Most cars made between 1885 and 1910, and with

gas engines, did not needs storage batteries. There was no

devices that required electricity! Ignition was left to the non-

electrical hot tube. Magneto happened later and was a self-

generating mechanism. Electric horns known as Klaxons,

made an appearance in 1908, and used expensive dry cells.

The first electric lights on autos appeared in 1898. In 1912 appeared the voltage regulator. Developed

by Delco, it solved the problem of battery overcharging. By then, the generator had been found.

Delco was also instrumental in the development of electric starter. First seen on Cadillac cars in 1912,

the electric starter then was a combination of a starter motor and generator with an overrunning

clutch and reduction gear. Gear teeth engaged the flywheel to provide a reduction of about 25 to 1

between the starting motor and crankshaft, allowing sufficient torque to crank the engine

successfully. Signalling the way ahead , the starter in those times was very unlike today's systems

where a starter-alternator combination can work as a start-stop mechanism! Interestingly, the

generator or dynamo mentioned above was also the starting point of hybrid cars. In 1899, Dr

Ferdinand Porsche, a young engineer at Jacob Lohner & Co, built the first hybrid vehicle. The car used

a petrol engine rotating at a constant speed to drive a dynamo, which charged a bank of

accumulators, These in turn, fed current to electric motors contained within the hubs of the front

wheels. Three fore there was no need to drive shafts, transmission, gears, straps chains or clutch. Due

to its extreme simplicity, the transmission operated, without losses produced by mechanical friction

with an incredibly yield of 83%. New developments in electronics led to the alternator replacing the

dynamo. The alternator would help generate more current. This would also make way for the

development of better lamps and other electrical systems. While the sealed beam head lamps

appeared in 1939, the alternator employed rectifiers and an in-built voltage regulator. Rising

popularity of electronics drove researchers. One big outcomes was the invention of Electronic Fuel

Injection (EFI) system. A system that has been fine tuned to power the current automobile, and the

result of which is power, efficiency, refinement and less emission. The arrival of digital

microprocessor increased the viability of EFI many folds. Such was the effect that electronics was

extensively tried out in other areas. Today's automobile makes it hard to distinguish therefore, what

is electrical or electronic. So, if a sparkplug can be defined as part of electrical technology, the

NEWSLETTER FROM RAJESH JOSHI INSPIRATION 11th

January 2012

injector and various sensors are clearly electronic in nature. The combination of electrical and

electronic technology is inseparably and finds use in instrumentation, HVAC, wash/wipe and more. A

good example of the coming together of the two technologies is the electric power steering.

Found on cars like the Maruti Alto, this technology involves an electric motor fitted on the steering

rack. A torque sensor is located on the input on the steering rack. A torque sensor is located on the

input shaft and converts the steering torque input and its directions into voltage signals. There's also

the rotation sensor, which converts the rotation sped and direction into voltage signals.

An "interface" circuit, in turn, converts the signal from the torque sensors and rotation sensor into

signals the electronic control unit (ECU) can process. Inputs from the steering sensors are digested by

a monitors input from the vehicle's speed sensor. The sensors inputs are then compared to

determine how much power assists is required according to a pre-programmed "force map" in the

control unit's memory. The control unit then sends out the appropriate command to the "power unit".

Which then suppliers the electric motor with current. The motors pushes the rack to the right or left

depending on which way the voltage flow (reversing the current reverses the direction the motor

spins). Increasing the current to the motor increases the amount of power assist.

Applications like the electric power steering are common lace in modern automobiles. Servo motors

like the one used in an electric power steering can perform tasks as mundane as operating the

windows or the central locking mechanism. They also perform more interesting tasks like selective

applications of individual wheel brakes to retain control on a slippery road surface or inject highly

precise amount of fuel in the chamber! Electrical and electronics work the suspension of modern

autos too. US-based Bose Corporation, Known for producing high-end audio systems, has developed

a unique electromagnetic suspension system fir automobiles. Replacing traditional shock absorbers

and springs with electronic actuators, at the core is a linear electromagnetic motor, which is installed

at each wheel. Inside the linear electromagnetic motor are magnets and coils of wire. When electrical

power is applied to the coils, the motor retracts and extends creating motion between the wheel and

car body. With speed as the key advantage, the linear electromagnetic motor responds swiftly to

counter the effects of bumps and potholes, maintaining a comfortable ride. Additionally, the motor

has been designed for maximum strength in a small package, allowing it to put out enough force to

prevent the car from rolling and pitching during electrical power to the manoeuvres. A power

amplifier delivers electrical power to the motor in response to signals from the control algorithms.

The amplifiers are based on the switching amplification technologies pioneered by founder, Dr Bose

at MIT in the early 1960s- technology that led to the founding of Bose Corporation in 1964. The

regenerative power amplifiers allow power to flow into the linear electromagnetic motor and also

allow power to be returned from the motor . For example, when the Bose suspension encounters a

pothole power is used to extend the motor and isolate the vehicles occupants from the disturbance.

NEWSLETTER FROM RAJESH JOSHI INSPIRATION 11th

January 2012

On the far side of the pothole, the motor operates as a generator and returns power back through

the amplifier. In so doing, the Bose suspension requires less than a third of the power of a typical

vehicles's air condition system.

The most visible application where electrical, electronic and lighting technologies unit are the

modern-day lighting systems. Illuminating not just the road ahead, lamps in an automobile play

various functions, that of the tail light; brake light turning signal and more. The reliability of LED

technology has seen its use go up in centrally mounted brake light. LED technology is also finding its

way into head lamps and tail lamps. Offering very long life and an uncanny resistance to vibration,

LEDs have found a place in lighting systems as daytime running lights and various signal and marker

lights. The commercial vehicle industry has rapidly adopted LEDs for virtually all signalling and

marking functions on trucks an buses, because in addition to the fast rise time and concomitant

safety benefit, the extremely long service life of the LEDs reduces vehicle downtime. Almost all

commercial vehicles use exteriors lighting devices of standardised format and fitment, which has

cost-reduced and sped the changeover. LED lamps have also proved to be a feasible alternative to

traditional light sources for flashing beacon lights on vehicles such as maintenance trucks.

Automakers like Mercedes Benz have engineered flashing LED brake lamps. Dubbed Adaptive Brake

Lights, these brakes lights are only activated when the brake pedal is pushed heavily for a hard stop.

Use of LED clusters as lamp modules, courtesy the LED' ability to lit up instantaneously has led

automakers to experiment with such safety enhancing features. Dictated by regulations that call for

smaller carbon footprint and less emission most automakers are striving to develop new technologies

that are lighter and reliable. Electrical electronic and lighting technologies are not out of the purview.

Wires have long given way to CAN-Bus systems in autos. Newer technologies like LEDs and

electronically adjustable ride height, BAS, ESP, etc., are turning autos more efficient. However, hybrid

ad electric cars are calling for he next best. This has led manufactures and suppliers to hunt for newer

technologies like Li-ion battery technology, LED lighting technology, regenerative braking technology

and more.

The automobile of tomorrow is certain to be far removed from the one today. It may have completely

given up on fossil fuels. This would propel the importance of electrical electronic an lighting

technology to a new high . The Result would most probably be a vehicles that is zero emission

complaint an self driving. All it would requires is a login, password and a command! A development

that Allesandro Volta would have watched with great interest.(AF)