Download Electronics and Circuit lab Fall 2016 Egr110

Electronics and Circuit lab
Fall 2016 Egr110
Goal:
Circuit’s lab will provide students with a basic understanding of electronic principles, basic
breadboard management and general circuit construction. This will help students as they
pursue the final EGR110 design project, which will include components of electronics and
circuit building. Students will learn theory, relevance and will complete hands on, group
activities.
ELECTRICAL BASICS
What is electricity?
Electricity is a natural occurrence that takes place in nature. For this lab we will focus on the
electricity that powers our homes, devices and tools. Electric current is defined as the flow
of an electrical charge, which can consist of any moving charged particles, most commonly
these are electrons. Engineers create and harness electricity using damns, turbines, and other
means to send power to cities. It is a vast and fascinating topic, but for today’s class we will
be learning about basics of electrical circuits, electrical definitions and
Electrical definitions:
 Voltage: Also called Electrical Potential. This is the ability of an electric field to do
work with a charge. This is measured in Volts and is seen as the symbol V.
 Amperage: Also called Electrical Current. This is the flow of the electrons
measured in Amps and seen as the symbol I. Also, the rate of flow, an Amp is equal
to one coulomb per second.
 Resistance: The measure of how difficult it is for electricity to pass. Electricity will
always pass through the path of least resistance.
 Electrical Circuit: A configuration of electrical components that produce a specific
outcome for directing correct power to an electrical device.
These three values are used to make up Ohm’s law, which is shown below:
𝐶𝑢𝑟𝑟𝑒𝑛𝑡 =
𝑉𝑜𝑙𝑡𝑎𝑔𝑒
𝑉
𝑂𝑅 𝐼 =
𝑟𝑒𝑠𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑅
Ohm’s law can help us calculate the necessary values for voltage, current or resistance in any
given circuit we may work with.
Electrical Components:
Many different electrical components exist for creating different circuits. Below are a few
components we have for our purposes
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Batteries are used for storing
electricity to power a circuit. A battery
can be any power source.
Battery
Battery symbol used in
circuit diagrams
Resistor Symbol
Resistor
LED Symbol
Resistors are used for slowing down
electrical current as it goes to various
components. Resistors are color coded
to
indicate
their
values.
Potentiometers are three terminal
resistors that can form adjustable
voltage. Resistance is measured in
Ohms
LED’s or light emitting diodes are
commonly used as indicator lights in
electronics. The symbol shows which
direction the LED needs to be placed
in the circuit; electricity should flow in
the direction of the arrow.
LED
Capacitors are used
electrical charge.
Capacitor
for
storing
Capacitor Symbols
A push button switch shown can be
used to complete or breakup a circuit.
Push Button Switch
Switch Symbol
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There is not enough time in this lab to cover all types of components for circuit building.
There are numerous sensors, printed circuit boards and components you can power and use
to create advanced electrical systems. Circuit building will be integral to your project. Below
are the basics of circuit diagram reading and construction.
CIRCUIT DIAGRAMS
A circuit diagram draws out the schematic necessary for powering a specific circuit. In this lab you
will complete three basic circuits, one of which will be used in your next lab for programming.
Circuit Basics:
Here are some tips for circuits:
 A circuit must be closed to work. CLOSED. This means there can be no breaks,
and the electrical current must flow from a positive to a negative/ground.
 Some components are directional, meaning they must be put into the circuit in a
specific orientation. LED’s, some capacitors are examples.
 Certain components can be connected in SERIES or PARALLEL to move electrical
current throughout a circuit in a specific way.
o Series: Components are connected one right after the other, like a long
chain
o Parallel: Components are connected at both ends, think stacked together
 Make sure you don’t ‘overpower’ or ‘under power’ and components. A light hooked
directly to a battery may immediately burn out. Make sure you have proper
resistance, amperage and voltage for each component (Remember Ohm’s law!)
Circuit Diagram:
Left, is a basic circuit diagram. We have a four
component Diagram, A battery, a switch (S1), a
resistor (R1) and a Diode (D1). The Electrical
Current flows from the battery through the switch,
then to the resistor and finally the diode before
returning to the battery. The circuit, however, is
not complete until S1 is closed. This circuit should
light the diode at the end.
This is a series circuit. All components are attached
end to end in one single chain. If any part of the
chain is broken the circuit will no longer work.
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Left is a more complex circuit that does the same
task as the first circuit. It lights a diode once a
switch is closed. This time, we have three resistors,
connected in parallel. If we remove any resistor,
our circuit will still work, because there will still be a
path for electricity to travel back to the battery.
Circuit diagrams can get much more complex and difficult. For now, we will work with the
two circuits above. We will build them using a breadboard. A breadboard is used for
making an experimental model for an electric circuit. It is a test board, you can use to
change and make circuits quickly.
A breadboard
Breadboards allow you to poke the ends of components and wires into holes that connect
the components underneath the plastic top. Below is a diagram of how a breadboard
connects components. In the center, each column is connected, meaning any parts you
connect there will be at the same point. Each ‘dot’ is a point where a component end can
go. BUT, remember for a part to work, you cannot connect both ends of a component into
the same column. That would ‘Short’ or ‘cutout’ that component as it would have no thing
to flow across. This will make much more sense when you complete your first activity!
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Breadboard inner workings
HANDS ON ACTIVITIES
Activity One: Build a circuit to light and LED
Materials:
1. Breadboard
2. LED
3. Push Button Switch
4. Wires
5. Battery and holder with wires
6. Resistor (Value 100 Ohms)
7. Volt/Amp meter
Use the breadboard and components to create the circuit shown. Make sure to fully
complete your circuit, you should create one long chain of parts that makeup a whole circuit.
You will know your circuit worked when the switch is hit and LED lights up.
After your circuit is working, you will measure the voltage and amperage across each
component (With the switch closed) and record it in the table below.
Component
Switch
Voltage (Volts)
Amperage (Amps)
Resistor
Diode
What happens to Voltage as you go around the circuit? What about Amperage?
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WHEN YOU’VE COMPLETED TASK ONE, TELL THE LAB COORDINATOR
AND SHOW THEM
Activity Two: Create a Parallel Circuit to light an LED
Materials:
1. R1: 100 ohm
2. R2: ??? ohm
3. R3: ???ohm
Modify your first circuit to have three resistors in parallel. Once you’ve done this, measure
the voltage and amperage across each resistor. Take out one resistor and see if the circuit
still works. Does the brightness of the LED change with removal of certain resistors?
Component
Resistor 1
Voltage (Volts)
Amperage (Amps)
Resistor 2
Resistor 3
Diode
How does Amperage and Voltage change across the diode with the removal of one of the
resistors?
WHEN YOU’VE COMPLETED TASK TWO, TELL THE LAB COORDINATOR
AND SHOW THEM
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Activity Three: Adding Arduino and Building your circuit for next lab
Arduino will be discussed in much more detail next class. But, in short, Arduino is another
electrical component that helps you interface electrical circuits with a computer. Using the
Arduino board, a PCB, you can monitor the different items on your circuit using a computer
and programming. This will test your circuit building skills. Once you’ve built this circuit,
we will explore programming next class.
Materials:
1. Arduino board
2. Breadboard
3. Wires
4. LED
5. R1: Photoresistor
6. Speaker
7. R2,3,4 (values given on diagram)
8. Button
WHEN YOU’VE COMPLETED TASK THREE, TELL THE LAB
COORDINATOR AND SHOW THEM
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