Maitland Grossmann High School - meprogram.com.aumeprogram.com.au/wp-content/uploads/2016/03/... ·...
Transcript of Maitland Grossmann High School - meprogram.com.aumeprogram.com.au/wp-content/uploads/2016/03/... ·...
2
Electronics activities should be confined to projects that only use extra - low-voltages. The activities
include connecting electronic components in differing ways to create many useful and fun projects; these
components have names such as resisters, diodes, transistors and capacitors.
Hazards that may be encountered in electronics activities could include:
Burns: from hot the soldering iron. You can also receive a burn
from the heat that remains in the electronic components and wire
after it has been soldered.
The hot soldering iron can melt the protective insulated leads and
other equipment exposing live electrical wire that could cause
electric shock.
Flux is a mild acid solution and it corrosive form can burn skin.
Cuts from wire, sharp edges of materials, knives and cutting tools.
Breathing difficulties if excessive toxic fumes are inhaled during
the soldering process
The work area should be appropriate for electronics activities. Bench tops should be made of a suitable
material. Seat and bench heights need to be considered.
Adequate supervision of students in the work area should be maintained at all times.
First aid equipment and supplies should be available and easily accessible.
All equipment should be in good condition and be regularly maintained.
Electrical equipment should be inspected regularly and where possible.
Tools and materials should be stored appropriately to prevent personal injury from cutting edges, sharp
material edges and wire.
Ventilation such as having windows open and the use of fans is recommended when soldering because
the fumes given off may be harmful if inhaled in excessive amounts.
Fluxes assist the soldering process. Contact with the flux should be avoided as it is a mild corrosive
liquid and when heated the fumes from these fluxes can be toxic if inhaled.
A suitable soldering station - cradle should be used which allows the hot soldering iron to be stored and
stop it from coming into contact with anything, or any one.
Power boards with overload protection should be used.
All students should be given sufficient instruction in the safe operation of all the tools, components and
procedures involved with electronics, design and technology.
Safety glasses reduce the risk of any splash of flux or other caustic liquid from entering the eyes. These
glasses can also reduce the risk of any other object from entering the eyes.
The general use of electricity inherently includes potential hazards that would normally require
precautions to be implemented including:
- Never allow the use of an electrical appliance with a damaged plug or lead
- The power switch must be switched off before removing the plug
- Never attempt to touch a tool or lead where exposed conductors can be seen. Notify the teacher who
will switch off the power to the room immediately.
- Electrical tools must never be operated close to water or with someone with wet hands. Therefore all
work areas are to be kept clean and dry at all times.
3
The energy sources we use to make electricity can be
renewable or non-renewable, but electricity itself is neither
renewable nor non-renewable.
Electricity is the flow of electrical power or charge. It is both
a basic part of nature and one of our most widely used forms
of energy.
Electricity is a form of energy that we use in our everyday
lives. We use it in our homes, business and industry. So what
exactly is electricity? No one really knows! We cannot see it,
it has no weight, it has no shape, but it is everywhere.
To understand what electricity is we need to learn more
about the atom, since everything around us is made up of
atoms.
Atoms are so small that we cannot see them with the human eye. They
consist of three tiny particles:
PProtons - positive charge
Electrons - negative charge
Neutrons - neutral charge
When the electrons in an atom become loosely attached they can easily travel from one atom to another
via conductors such as electrical wires. When this occurs a current or charge is created and we have
electricity or also known as an electric current.
(Electric current is a flow of electric charge through a medium. This charge is typically carried by
moving electrons in a conductor such as wire. It can also be carried by ions in an electrolyte, or by both
ions and electrons in a plasma)
Electrons are strange and unusual little fellows. Strange things happen when too many or too few of the
little fellows get together. Some are attracted to each other whilst some things or some repel each other
away. Occasionally you may see a spark of light and sound. The light and sound may be quite small or
may be as large as a bolt of lightning. When electrons gather, strange things happen. These strange things
are called electricity.
The proton has a positive charge, the neutron has no charge (neutron, neutral get it?) and the electron has
a negative charge. These charges repel and attract one another kind of like magnets repel or attract. Like
charges repel (push away) one another and unlike charges attract one another. Generally things are
neutrally charged. They aren't very positive or negative; rather have a balance of both.
4
Things get charged when electrons move. Electrons are negatively charged particles. So if an
object has more electrons than it usually does, that object would have a negative charge. If an object has
less electrons than protons (positive charges), it would have a positive charge. How do electrons move?
Depending on the type of atom they are a part of, they are quite willing to jump ship and go somewhere
else. The way to get them to jump ship is to rub things together. This is where we explore various types
of crazy materials, as some material can carry these atoms called electrons better than other materials
these have names, material that conduct electron very well are called conductors, they are called
conductor because of their ability to carry and electric current. Material that don’t conduct electricity well
are called resistors and have properties called insulators, just as some properties conduct electricity well
some properties resist well too, like glass rubber and porcelain which is a really good resistor of electrical
charges or really good insulators.
There are two basic types of circuits. In a series circuit,
there is only one complete loop for the current to take. A
parallel circuit has multiple loops where the current can
travel. The examples shown use 2 light bulbs and a
battery.
A circuit diagram is like a map. It shows where the
various components go, and how electricity flows
through them to complete a circuit.
The following electronic components are what you will use during your construction of the continuity
tester. A picture, description and the way the component is represented on a wiring diagram will be
shown.
Batteries are containers that store the electrical potential.
They contain chemicals that react to provide a flow of electricity.
All batteries have a positive terminal and a negative terminal of
some sort, so that we can connect them to electrical circuits or
provide power for our electrical appliances. In a circuit the battery is represented
by the short thick line the positive and the long thin line for the negative for a
battery.
As batteries only come in limited voltages, many components require the voltage and
current flow to be reduced so that the components will not be damaged. Resistors are
used to limit the flow of electrical current. A colour code is printed on resistors, so we
can tell how much resistance is provided. In a circuit the resistor is represented by a
rectangle with two thin lines coming out each end as shown above.
A diode allows electricity to flow in one direction only and blocks the flow in the
opposite direction. They may be regarded as one-way valves and they are used in various
circuits, usually as a form of protection. There are different types of diode but their basic
functions are the same. These are noted below along with examples of diodes in use.
5
6
7
Approximately 99% of all power generated is done so via rotating electrical machines. Similarly,
approximately 75% of all electrical power is consumed in rotating machines. Electrical machines are
important! Motors (and generators) have evolved for around 100 years. Many clever minds have been
applied to the task of inventing, refining and applying all manner of machines to many different and
specific applications. Consequently, we cannot expect to understand all of the types of motors that exist.
Your Electric car is powered by a small electric motor, below is an image of what is inside.
8
http://www.renewableenergyworld.com/rea/video/solar-gardens-bring-solar-to-the-masses
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/motdc.html
9
The purpose is to tell the reader how to do or make something.
The information is presented in a logical sequence of events,
which is broken up into small sequenced steps. These texts are
usually written in the present tense.
The most common example of a procedural text is a recipe.
There are different procedural texts for different purposes:-
Texts that explain how something works or how to use instruction /operation manuals e.g. how to use the
video, the computer, the tape recorder, the photocopier, the fax.
Texts that instruct how to do a particular activity e.g. recipes, rules for games, science experiments, road
safety rules.
Texts that deal with human behaviour e.g. how to live happily, how to succeed.
Goal - clearly stated (often in the heading)
Materials - listed in order of use
Method - the steps are chronological and are numbered or listed
Recipes usually have the information presented in at least two basic groups: ingredients and method.
Games instructions usually include instructions on how to play, rules of the game, method of scoring, and
the number of players.
Scientific experiments usually include the purpose of the experiment, equipment, procedure, observations
and conclusion.
The text usually:
focuses on generalised people rather than individuals (first you take, rather than first I take)
the reader is often referred to in a general way, ie. pronouns (you or one)
action verbs (imperative verbs), (cut, fold, twist, hold etc)
simple present tense (you cut, you fold, you mix)
linking words to do with time (first, when, then) are used to connect the text
detailed information on how (carefully, with the scissors); where (from the top); when (after it has set)
detailed factual description (shape, size, colour, amount)
10
The U.S. passed its peak of oil production in 1970. During the dual oil
crises of the 1970's the U.S. imported 35% of its oil needs, and today it
imports nearly 70% of its oil needs. The world oil peak is due to happen
relatively soon, either it has already happened, or it will occur within the
next 10-20 years. Oil availability and price follows a clear supply/demand
arrangement, the demand for oil is rising as population increases and as
oil-burning technology is more widely deployed around the world.
Oil is derived from fossil
times, the total supply is limited to the amount in the
ground, the total production capacity is related to the
quality of the oil fields, and when the oil runs out it will
require millions of years for the planet to recapture the
carbon and turn it into oil again.
Electric vehicles do not (directly) rely on oil to move. Because the electrons can come from any source it
gives society huge flexibility in choosing the source of the electrons.
Burning oil produces a wide range of poisonous chemicals in the exhaust. Studies have shown these
poisonous chemicals to cause a range of illnesses from asthma to cancer. Burning less oil will decrease
the amount of poisonous vapours in the atmosphere. Electric vehicles do not (directly) rely on oil to
move. The electrons can come from any source, including ones who do not burn fossil fuels. So long as
the majority of vehicles are burning fossil fuels the quality of the air will be negatively impacted, we all
will be breathing these poisons into our bodies, and our health will be negatively impacted.
Again, burning fossil fuels produces a range of poisonous chemicals. These go into the air, water, ground,
and end up in our food. Burning fossil fuels means de sequestering carbon that had millions of years ago
been plants and animals. The carbon which had formerly been those plants and animals is being added to
the ecosphere, and increasing the total amount of carbon in the ecosphere. Carbon levels are directly
responsible for effects like global temperature. The mining, refining, transportation, and consumption of
fossil fuels involve occasional accidents that spill these fuels into the environment. Crude oil is highly
toxic and directly negatively impacts the wellbeing of wildlife. Oil spills are difficult to clean up and the
effects last for years.
11
An electric car is powered by an
electric motor instead of a gasoline
engine. The electric motor gets
energy from a controller, which
regulates the amount of power—
based on the driver’s use of an
accelerator pedal. The electric car
(also known as electric
vehicle or EV) uses energy stored in
its rechargeable batteries, which are
recharged by common household electricity.
Unlike a hybrid car, which is fuelled by petrol and uses a battery and motor to improve efficiency, an
electric car is powered exclusively by electricity. Historically, EVs have not been widely adopted because
of limited driving range before needing to be recharged, long recharging times, and a lack of commitment
by automakers to produce and market electric cars that have all the creature comforts of gas-powered
cars.
That’s changing. As battery technology improves, simultaneously increasing energy storage and reducing
cost, major automakers are expected to begin introducing a new generation of electric cars.
Electric cars produce no tailpipe emissions, reduce our dependency on oil, and are cheaper to operate. Of
course, the process of producing the electricity moves the emissions further upstream to the utility
company’s smokestack—but even dirty electricity used in electric cars usually reduces our collective
carbon footprint.
12
The electric vehicle is yet to make its break in Australia although recent announcements in the US and
the UK demonstrate that it is only a matter of time before Car Company’s click on to the potential market
here. Currently there are a number of electric vehicle conversion and parts companies in Australia, and it
is likely that there will be much more in the future. You can read more at Electric Vehicle Revolution
Starts Now
(http://www.greenchipstocks.com/report/the-electric-car-revolution-starts-now/479)
When coupled through Vehicle to Grid (V2G) systems, electric
vehicles can allow the introduction of more renewable energy
sources such as wind, wave, solar and geothermal energy onto
our electricity transmission system. Furthermore the
introduction of the carbon trading market in Australia in 2013
should prompt financial incentives for individuals and
companies to look into low carbon emitters such as electric
vehicles, and the benefits they can bring to sustainable energy
increase.
There is no doubt that the electric vehicle will play a major role in the development of a more sustainable
Australia in the very near future. If you want to find out more about electric vehicles or are interested in
converting your car, there are a number of resources that you can Google. You may also want to check
out this Build Your Own Electric Vehicle Link if you want to try and build your own.
13
There are a number of other car options which reduce the carbon footprint of the vehicle;
however these technologies are nowhere near as efficient as electric vehicles. Some of the more efficient
vehicle technologies include Hybrids, Hydrogen Powered Vehicles and Air Powered Vehicles. There are
also a number of incentives from the Government to convert your car to gas which is worth looking into,
although gas is still a non renewable resource which Australia exports, will soon have a tax associated
with it, and is of course running out. There are also some impressive diesel vehicles coming onto the
Australian market with better MPG performance, however electric vehicles and the benefits of vehicle
connected electric vehicles put them well ahead of the competition, especially when we look at carbon
emissions.
Use much less energy than combustion engine driven vehicles
Can be charged directly from the sun or by wind turbines
Batteries can act as demand management storage during the 95% of time the vehicle is parked using
vehicle to grid
Electric cars don't stink and don't clog up our streets with carbon monoxide and other nasties
Electric cars have instant full torque acceleration the moment you press the accelerator
The centre of mass of the vehicle can be lower as weight is distributed more intelligently around the
perimeter of the vehicle which allows for better handling
They can be charged anywhere there is access to electricity and this can come directly from solar panels
or small home based wind turbines. I.e. no more trips to the petrol station.
A huge onboard voltage allows you to run a fairly hefty sound system which doesn't require bulky and
expensive inverters
They are quiet and elegant. Electric cars are green and some are most definitely sexy.
Electric vehicles require no oxygen, so you can design one which runs under water!
http://www.sustainableenergy.com.au/electric_vehicles.html>
http://www.sustainableenergy.com.au/renewable_energy.html
http://www.greenchipstocks.com/report/the-electric-car-revolution-starts-now/479
A fuel cell is a device that converts the chemical energy from a fuel
into electricity through a chemical reaction with oxygen or another
oxidizing agent. Hydrogen is the most common fuel, but
hydrocarbons such as natural gas and alcohols like methanol are
sometimes used. Fuel cells are different from batteries in that they
require a constant source of fuel and oxygen to run, but they can
produce electricity continually for as long as these inputs are
supplied.
Fuel cells offer a significant advantage over traditional combustion-
based thermal energy conversion, in that they provide efficiencies of
electrical power supply in the range of 35 to 55%, whilst
causing very low levels of pollutant emission.
http://www.keepbanderabeautiful.org/hydrogen.html
14
Fuel cells generate electrical power quietly and efficiently, without pollution. Unlike power sources that
use fossil fuels, the by-products from an operating fuel cell are heat and water. With a fuel cell, chemicals
constantly flow into the cell so it never goes dead -- as long as there is a flow of chemicals into the cell,
the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the
chemicals.
Fuel cells power buses, boats, trains, planes, scooters, forklifts, even bicycles. There are fuel cell-powered
vending machines, vacuum cleaners and highway road signs. Miniature fuel cells provide electricity for
cellular phones, laptop computers and portable electronics. Hospitals, credit card centres, police stations,
and banks are all using fuel cells to provide power to their facilities. Wastewater treatment plants and
landfills are using fuel cells to convert the methane gas they produce into electricity. Telecommunications
companies are installing fuel cells at cell phone, radio and 911 towers. The possibilities are endless.
Hydrogen can be burned either to provide heat, or to drive turbines, or in internal combustion engines for
motive and electrical power. Many of these technologies need improvements in materials and processes to
improve efficiency and durability.
http://ec.europa.eu/research/energy/eu/research/fch/background/index_en.htm
Penn State researchers have developed a microbial electrolysis cell, which they call BEAMR, to produce
hydrogen. The process uses bacteria to break down organic material, such as acetic acid and cellulose. A
small external burst of voltage aids in boosting hydrogen production.
15
Gears are used in tons of mechanical devices. They do several
important jobs, but most important, they provide a gear
reduction in motorized equipment. This is key because, often, a
small motor spinning very fast can provide enough power for a
device, but not enough torque. For instance, an electric
screwdriver has a very large gear reduction because it needs lots
of torque to turn screws, but the motor only produces a small
amount of torque at a high speed. With a gear reduction, the
output speed can be reduced while the torque is increased.
Another thing gears do is adjust the direction of rotation. For
instance, in the differential between the rear wheels of your car,
the power is transmitted by a shaft that runs down the centre of
the car, and the differential has to turn that power 90 degrees to
apply it to the wheels.
There are a lot of intricacies in the different types of gears. In
this article, we'll learn exactly how the teeth on gears work, and
we'll talk about the different types of gears you find in all sorts
of mechanical gadgets.
http://science.howstuffworks.com/transport/engines-equipment/gear.htm
16
To understand the gear you first have to understand the lever. The
lever and fulcrum make up a simple machine where a stiff beam (the
lever) rotates about a fixed pivot (the fulcrum).
The principle of the lever has been used since before written language. Levers were initially invented so
that heavy stone blocks could be moved using only muscle power. Levers still form the operating principle
behind many common machines, both powered and hand operated. A practical lever includes the lever itself
and the fulcrum. To work properly, the fulcrum is usually fixed in place relative to the lever.
Like other simple machines, the lever is best understood through the concepts of input and output forces.
The diagram above shows a lever. The hand pushing down on the lever is the input force. When the hand
pushes down the rock will rise up. This is the output force. The output force can be larger or smaller than
the input force, depending on the length of the lever and where you place the fulcrum.
The diagram above shows a little longer lever. You will notice side "A" is equal to side "B". Or the input
force equals the output force. But notice that side "B" is longer than side "A". Therefore the output force
will be larger. This is a ratio of output force to input force called mechanical advantage.
This is why we can change a tire on a car by ourselves. With very little input force we can raise the car to
change the tire. (output force.)
Although they may seem very different, wheels and gears are closely related
to levers. The wheel is essentially a rotating lever. Think of the diagram of the
lever above as being bent into a circle. The centre of the circle is the fulcrum.
In math we call this the centre point.
17
Figure 1. Animation of peg wheel gear (see link below). On any
gear, the ratio is determined by the distances from the centre of the
gear to the point of contact. For instance, in a device with two
gears, if one gear is twice (B) the diameter of the other, (A) the
ratio would be 2:1.
http://www.engineerstudent.co.uk/understanding_gears.html
One of the most primitive types of gears we could look at would
be a wheel with wooden pegs sticking out of it.
The problem with this type of gear is that the distance from
the centre of each gear to the point of contact changes as
the gears rotate. This means that the gear ratio changes as
the gear turns, meaning that the output speed also changes.
If you used a gear like this in your car, it would be
impossible to maintain a constant speed -- you would be
accelerating and decelerating constantly. Many modern
gears use a special tooth profile called an involute. This
profile has the very important property of maintaining a
constant speed ratio between the two gears. Like the peg
wheel, the contact point moves; but the shape of the
involute gear tooth compensates for this movement.
Spur gears are the most common type of
gears. They have straight teeth, and are
mounted on parallel shafts. Sometimes,
many spur gears are used at once to create
very large gear reductions. Spur gears are
used in many devices that you can see all
over HowStuffWorks, like the electric
screwdriver, dancing monster, oscillating
sprinkler, windup alarm clock, washing
machine and clothes dryer. But you won't
find many in your car.
This is because the spur gear can be really
loud. Each time a gear tooth engages a
tooth on the other gear, the teeth collide,
and this impact makes a noise. It also
increases the stress on the gear teeth.
When two spur gears of different sizes mesh together, the larger gear is called a wheel, and the smaller
gear is called a pinion. In a simple gear train of two spur gears, the input motion and force are applied to
the driver gear. The output motion and force are transmitted by the driven gear. The driver gear
rotates the driven gear without slipping.
18
Bevel gears have teeth cut on a cone instead of a cylinder blank. They are
used in pairs to transmit rotary motion and torque where the bevel gear
shafts are at right angles (90 degrees) to each other.
A gear which has one tooth is called a worm. The tooth is in the form of a screw
thread. A wormwheel meshes with the worm. The wormwheel is a helical gear with
teeth inclined so that they can engage with the thread-like worm. The wormwheel
transmits torque and rotary motion through a right angle. The worm always drives
the wormwheel and never the other way round. Worm mechanisms are very quiet
running.
A rack and pinion mechanism is used to transform rotary motion into linear motion and vice versa. A
round spur gear, the pinion, meshes with a spur gear which has teeth set in a straight line, the rack.
Internal gears have better load-carrying capacity than external
spur gears. They are safer in use because the teeth are guarded.
http://science.howstuffworks.com/transport/engines-equipment/gear.htm>
http://www.fi.edu/time/Journey/Time/Escapements/geartypes.html>
http://www.fi.edu/time/Journey/Time/Escapements/geartypes.html>
http://www.fi.edu/time/Journey/Time/Escapements/gearint.html>
http://facweb.cs.depaul.edu/sgrais/Automaton.htm
19
This project requires the student to design and build an electric car using
a Scorpio Technology Lo-Rider kit. www.scorpiotechnology.com.au
This basic vehicle is suitable to introduce students to technology and
Electronics. After completion of the vehicle, it can be used for a variety
of experiments (physics or otherwise) or even paired with another
vehicle for racing and performance tests.
This is a basic four wheeled vehicle, with both front and rear wheels on
fixed axles. This vehicle:
• is capable of forward and reverse motion (direction of travel being
controlled by a two-way switch)
• has a choice of two gearbox ratios (at the construction stage).
The major aspects of this project are the design, construction and assembly of the vehicle. The design
stage is crucial. At this stage the location of all the components is worked out. Follow the instructions
from the job sheet to construct all the main components of the electric car. There are different aspects of
the design that can be modified to individualise your electric car.
The following components are supplied in a plastic bag, for the construction of one vehicle:
1 x Slide Switch (Centre Off)
2 x 52 mm dia. Wheels
1 x Battery holder (2 xAA)
2 x 38 mm dia. Wheels
1 x 2.5 mm.dia. 120mm long steel rod
2 x Self-tapping screws 2.6mm x 4mm long
1 x Plastic guide tube 100 mm long
1x Two Ratio Gearbox and Motor kit, consisting of:
1 x Two Ratio Gearbox
1 x 10T Pinion gear 1.9 hole
1 x 4.5V Electric motor (round)
2 x M2.6x 4 self-tapping Screws
b1) The following are available from us, and need to be ordered separately: AA batteries (HD), and a
2.3mm drill bit (to drill pilot holes for the self-tapping screws)
b.2) The following material is supplied by the school: fine, multi-strand electric hook-up wire (assorted
colours); black PVC insulation tape; suitable adhesive (Hot Glue or double sided foam tape), material for
the body of the electric car (Pine), and everything else!
20
If a high torque application is required, serrations should be
formed along the ends of the driven rear axle (the serrations can be
formed using eg. a cold chisel; but they must be shallow).
The axle for the front wheels uses plastic tubing as a bearing. The
plastic tubing can be fixed to the base by hot glue or double sided
tape. The steel axle should be first placed through the plastic
tubing, hot glue is then applied to the base. Hold each end of the
steel axle and press the tubing down into the glue. Make sure that
the tubing is parallel to the rear wheels, or the vehicle will travel in
a circle.
A choice of 2 gearbox ratios is available, and must be chosen prior to
assembly to the vehicle. The Gearbox itself is pre-assembled, and the
motor needs to be assembled to the Gearbox.
The choice of ratios available at the „Output” shaft are:
Single reduction (shaft A) = 1:5
Double reduction (shaft B) = 1:25
The motor, under load, turns at approximately these speeds.
- with 3 Volts (2xAA batteries) 6,500 RPM
- with 6 Volts (4xAA batteries) 12,600 RPM
Before starting assembly, the following must be done (based on the intended use of the gearbox):
select the desired gearbox ratio – one of the two available
cut off the other excess shaft
Press the 10T pinion onto the motor shaft.
HINT: Place the gear on the bench, insert the motor shaft into the worm gear’s hole and gently tap the
end of the shaft (where it exits the motor) with a small hammer. Stop when the worm gear is 3mm from
the motor’s body.
WARNING: Don’t just push the motor down by hand as this can push the motor armature out of its
bearings and jam the motor.
Solder a suitable length of wire to each of the motor’s terminals – prior to installing the motor in the
gear case.
Secure the motor to the gearbox case using the supplied two self-tapping screws.
21
To hold the gearbox in place, two, 2.3 mm holes must be drilled in the platform, to match 2 diagonally
opposite holes in the gear case, The self-tapping screws should be inserted from the top of the gear case to
the platform. Do not over tighten the screws (refer to the drawing for mounting).
6.1.1 The electric motor is nominally 3.0 volts. This is mounted as part of the Gearbox assembly.
6.1.2 The motor can operate between 1.5 and 6 volts. The kit is supplied with a 2 x AA battery holder,
which allows for 3 volts. If a different voltage is required, a different battery holder will need to be
purchased. Lower voltage gives slower speed, higher voltage means higher speed.
WARNING: It is recommended not to increase the power supplied to more than 6 volts, otherwise the
life expectancy of the motor may be significantly reduced.
6.2.1 The battery holder and switch are mounted on the base. The Two-way switch should be wired as
shown in the “Wiring Schematic”. This allows forward and reverse motion of the vehicle.
Good Luck! You’re now ready to roll. Now you have the race to look forward to. But before then, the
electric car should be tested. The class should build a test track on a long flat surface.
When you test your electric car, check for the following points.
Does the electric car travel in a straight path?
Are the wheels on straight?
Do the wheels spin freely?
Were the washers mounted with the axles?
Are the tires tight against the wheel hub? They should not spin on the hub.
Try to find out what might be causing problems.
The final stage of the process is to evaluate your design. From the criteria that you set yourself at the
beginning of the design process you need to determine if this project was successful. Remember that all
cars will be compared for excellence in design, neatest idea, best craftsmanship and fastest racing time.