basic circuits foundations of technology basic circuits © 2013 international technology and...

Foundations of Technology

Basic CircuitsBasic Circuits

© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology

Teacher Resource – Unit 4 Lesson 4

The BIG IdeaThe BIG Idea

Big Idea:

Troubleshooting allows users to continue to use and maintain the proper operation of a system or product.


Basic CircuitsBasic Circuits

All electronic circuits have a path for electrons to flow and an energy source.

Electrons will flow from the negative(-) to the positive(+).

The amount of electron flow will depend on resistance.


-

+

Direct CurrentDirect Current

Direct Current (DC) electrons flow in only one direction.

Examples: a battery, hand held electronics such as an iPod and other devices like an automobile


Alternating CurrentAlternating Current

Alternating Current (AC) electrons flow back and forth, negative (-) to positive (+) to negative (-)

Examples: the electrical appliances at your house


The AtomThe Atom

All matter is made of atoms.

The atom is made of three things:

Protons

Neutrons

Electrons


P NP

NP

N

NP

e-

e-

e-

e-

Electrons rotate around the group of proton and neutrons.

When electrons move from one atom to the next, it is called electron flow.

ElectronsElectrons


P NP

NP

N

NP

e-e-

e-

e-

Opposite electrical charges always attract and like electrical charges always repel.

Balanced atoms normally have an equal number of electrons and protons, which means they are electrically neutral.

ElectronsElectrons


P NP

NP

N

NP

e-e-

e-

e-

e- e-

e+ e-

Ion particles occur when an atom loses or gains an electron causing an imbalance.

When an imbalance occurs, Ion's will take or release an electron to become balanced again, causing electron flow.

IonsIons


P NP

NP

N

NP

e-e-

e-

e-

Ion’s can be charged:

Positive (+), which has one less electron than proton.

Negative (-), which has one more electron than proton.

The positive Ion attracts to a negative Ion to become balanced.

IonsIons


P NP

NP

N

NP

e-e-

e-

e-

Electrons rotate around the atom at different orbits.

Bound electrons orbit around the nucleus on the inner rings

Free electrons are loosely held and orbit around the outermost ring which is known as the valance ring

Electron OrbitsElectron Orbits


e- e-

e-

e-

+

e-

e-

e-

e-

e-

e-

e-

e-e-

e-

e-

e-

e-e-

e-

e-

e-

e-e-e-

e-e-e-

e-

e-

An insulator is any material that prevents the flow of electrons.

Insulators typically have five to eight free electrons in the outer ring, which means they are tightly held to the atom and cannot easily move.

Insulator material includes glass, rubber and plastic.

InsulatorsInsulators


e- e-

e-

e-

+

e-

e-

e-

e-

e-

e-

A conductor is any material that easily allows electrons to flow.

Conductors typically have one to three free electrons in the outer ring, which means they are loosely held to the atom and can easily move.

Conductor material includes copper and gold.

ConductorsConductors


e- e-+

e-

e-

e-

A semiconductor is neither a good conductor or insulator.

Semiconductors have exactly four free electrons in the outer orbit and are commonly used to manufacture diodes, transistors, and integrated circuit chips.

Semiconductor material includes carbon, silicon, and germanium.

SemiconductorsSemiconductors


e- e-+

e-

e-

e-

e-

Proposed by George Ohm, and is the relationship between Voltage, Current and Resistance.

Ohm suggested that if you double the Voltage across something that provides resistance, then the current would double.

Voltage (V) = Current (I) X Resistance (R)

Ohm’s LawOhm’s Law


-

+V

R

I

Voltage is the electrical force that moves electrons through a conductor.

Voltage is electrical pressure that pushes electrons.

VoltageVoltage


V

I R

Current is the quantity or flow rate of electrons moving past a point.

Current flow is also known as amperage, or amps for short.

CurrentCurrent


V

I R

Resistance is the force that reduces or stops the flow of electrons and opposes voltage.

ResistanceResistance


V

I R

In a Series circuit, the current through two or more resistors is the same, and the circuit is connected in a series.

The total resistance of the collection is the sum of the individual resistances.

In series, electrons have only one path to follow to complete the circuit and must travel through all components.

Resistors in SeriesResistors in Series


In a Parallel circuit, the voltage through two or more resistors is the same, and the circuit is connected in parallel.

The total resistance of the collection is divided among the three resistors .

In parallel, electrons have multiple paths to follow to complete the circuit and do not need to travel through all components in the circuit to do so.

Resistors in ParallelResistors in Parallel


Parts of the Electronics Parts of the Electronics KitKit


2 Battery Snaps

Battery

Speaker

SCR Capacitors

PhotocellPush Button

Transistors

Diode3 LED’s

555 Timer

Potentiometer

15Wires

Solderless Breadboard



LED Resistor 3904 Transistor Speaker

Diode Photocell 3906 Transistor Push Button

“Can” Capacitor Potentiometer Battery SCR

Ceramic Disc Capacitor



10

ohm

(B

row

n, B

lack

, B

lack

, G

old

)

2 @

47 o

hm

(Yello

w, V

iole

t,

Bla

ck, G

old

)

2 @

100

ohm

(B

row

n, B

lack

, B

row

n,

Gold

)

3 @

220

ohm

(R

ed,

Red

, B

row

n, G

old

)

3 @

330

ohm

(O

range, O

range

Bro

wn,

Gold

)

47

0 o

hm

(Yello

w,

Vio

let,

Bro

wn

, G

old

)

4 @

1K

ohm

(B

row

n, B

lack

, R

ed, G

old

)

2.2

K o

hm

(R

ed, R

ed, R

ed,

Gold

)

3.3

K o

hm

(O

ran

ge, O

ran

ge, R

ed, G

old

)

2 @

6.8

K o

hm

(B

lue, G

ray, R

ed, G

old

)

3 @

10K

ohm

(B

row

n, B

lack

, O

ran

ge, G

old

)16

K o

hm

(B

row

n, B

lue, O

range,

Gold

)

2 @

33K

ohm

(O

ran

ge, O

range,

Ora

nge, G

old

)

12

0K

ohm

(B

row

n, R

ed, Yello

w,

Gold

)

47

0K

ohm

(Yello

w,

Vio

let,

Yello

w,

Gold

)

Resistors have four (4) color bands on them called the “color code”

Band 1 = 1st Digit

Band 2 = 2nd Digit

Band 3 = Multiplier.

Band 4 = Tolerance

Gold = 5%

Silver = 10%

Color CodesColor Codes


The Breadboard includes two sides (a-e and f-j) and the “ditch” or the space in the middle.

The holes are connected by rows not columns.

Building a CircuitBuilding a Circuit


Build the circuit below:

Practice Building a CircuitPractice Building a Circuit


-

+9Volts

R = 1000 Ohms

I

1000 ohms resistor (brown, black, red, gold)

Use your simple circuit and measure for Volts, Current and Resistance.



-

+9Volts

R

I

Use the multimeter to measure the resistance.

Use the multimeter to measure voltage

Place the digital multimeter in series to measure current.


Do the math using Ohm’s Law to find the actual value of the resistor - What does it measure?



-

+9Volts

R

I

Use the multimeter to measure the resistance.

Use the multimeter to measure voltage

Place the digital multimeter in series to measure current.


basic circuits foundations of technology basic circuits © 2013 international technology and...

Documents

international technology

electron flow

equal number of electrons

electrical appliances

balanced atoms

big ideabig idea

group of proton

proper operation