This document provides an overview of the Electronics Merit Badge module on electronic components and what they do. It defines electronics and electricity, discusses conductors and insulators, and how electricity is measured. It also describes common electronic components like resistors, capacitors, transistors, integrated circuits and their functions. Measurement tools like multimeters and their uses are explained. Finally, it provides an introduction to schematic diagrams and symbols.

1. Electronics Merit Badge
Boy Scouts of America
Module 1 – Electronic Components
and What They Do
2014

2. Key Topics in This Module
1. Basic Electronics
2. Electronic Components
3. Schematics

3. What are Electronics?
• Electronics are devices made up of
electrical components that use
electricity to perform a task.

4. What is Electricity?
• Electricity is the flow of electrons, tiny
particles that are part of atoms.
• Electricity flows through conductors
• Electricity is blocked by insulators

5. Conductors & Insulators
• Conductors conduct (carry) electricity.
– Most Metals (Gold, Silver, Aluminum, Copper)
– Many Liquids (Water)
• Insulators insulate (don’t carry) electricity.
– Air
– Most Rubbers and Plastics
– Most Ceramics
– Wood and cloth (when dry)

6. How do we measure electricity?
• Current is the flow of electrons in a
conductor. Electrical current is
measured in amperes, or amps.
• Voltage is the electrical pressure that
pushes current to flow in a wire. The
unit of voltage is the volt.
• Electricity can do work. Electrical
power is measured in watts.

7. • High voltage • Low voltage

8. Where does Electricity
come from?

9. What tools can we use
to measure Electricity?
A Multimeter can be
used to measure:
• Volts
• Amperes
• Resistance
5.b.1

10. What tools can we use
to measure Electricity?
A Power meter is
used to measure
total watts used
over time
5.b.2

11. What tools can we use
to measure Electricity?
An oscilloscope is used to show
electrical signals in time
5.b.3

12. Why do we use tools
to measure Electricity?
Test equipment like
meters, oscilloscopes
and other tools are used
to make sure a circuit is
working right, or if it is
not, to find out what
needs to be fixed. Test
equipment is used to
measure volts, amps, or
other information in a
circuit.
5.b

13. Resistors slow down or
resist the flow of
electricity. Resistors are
measured in Ohms.
2.b.1

14. Resistor Color Codes

15. Capacitors act like a
stretchy container that
can store and release
electrons. Capacitance
is measured in Farads.
2.b.1

16. Inductors
Inductors act to
work against
changes in the
flow of current, like
a heavy flywheel.
Inductors are
measured in
Henries.
2.b.5

17. Diodes
Diodes only let
electricity flow
one way through
them, like a one-way
valve.
Some diodes
make light when
2.b.5
electricity flows through them.
These are called LEDs

18. Transistors can use a
small signal to control a
large signal, like a valve.
Transistors can act as
amplifiers or switches.
2.b.3

19. • Integrated Circuits combine
transistors, resistors and capacitors
into a single package to save space
2.b.4

21. Ohms Law
Ohms Law says that the current in a circuit
is the voltage divided by the resistance.
Example: Connecting a 1Kilo-ohm
resistor (1000 ohms) to a 9v battery lets
9 ÷ 1000 = 0.009 amps of current flow.
We can verify this with the multi-meter.
Try it yourself with different resistors and
batteries!
5.a

22. Schematic Symbols
Fuse Contains a thin wire which is made to melt which protects the rest of the
circuit from damage if there is too much current from a short circuit.
Battery Stores electric energy.
Resistor Resists the flow of electric current, reducing its flow.
Variable
resistor
Like a regular resistor, but adjustable. For example, the volume knob on
your stereo.
Earth
ground
A connection between the equipment (radio) and the earth, usually through
a copper pipe driven into the soil.
Chassis
ground
A connection of the negative side of the electronic circuit to the chassis, or
steel frame, of the equipment.

23. Schematic Symbols (cont.)
Capacitor Gets and stores an electric charge. Lets alternating current (AC - like in your
house) flow but stops direct current (DC - like from a battery).
Variable
capacitor
Same as a regular capacitor, but adjustable.
NPN
transistor
Amplifies a current.
PNP
transistor
Amplifies a current.
Coil Also called a choke, it works the opposite of a capacitor. It lets DC flow but
stops AC.
Tube A vacuum tube made of glass with wire filaments inside. Amplifies a current. It
has been replaced by transistors in most home equipment, but is still found in
some high power radio transmitters.

24. Schematic Symbols (cont.)
Antenna Sends radio frequency signals into the air.
SPST
switch
Single-pole single-throw switch. Has two positions, on and off. Like most light switches
DPDT
switch
Double-pole double-throw switch. A double-throw switch has three positions. It can
switch one input to one of two outputs - sort of like the switch you put on your television
to switch between watching TV and playing your video game. The double-pole means it
can switch a pair of inputs to either of two pairs of outputs.

25. A Schematic Diagram
Requirement 1
2.a

26. Electronics Merit Badge
Boy Scouts of America
Module 2
Soldering and Safety
2014

27. Safety
• When working on electronics, it is
important to:
• Protect yourself!
• Protect the electronics!
• Protect the work area!

28. How can you connect
electrical parts?

29. Printed Circuit Board
• A Printed Circuit Board or PCB is how
most electronics are built today.
• The PCB is a board of insulating
material. Electrical parts are mounted
to it, and copper strips called traces
and pads make electrical connection
between the parts.
• The parts are attached to the PCB by
soldering.
3.c

30. Printed Circuit Board

31. Soldering
• Soldering is a way to connect electronic
parts together to make a circuit
• Solder is a kind of metal that melts
at a ‘low’ temperature: 600ºF.
• It acts as a kind of glue that holds
the parts to the board and makes
an electrical connection.
• A Soldering Iron is used to heat up
the parts to melt the solder.

32. Soldering Safety
• There are things that you must do to be
safe when soldering:
• The soldering iron is HOT. Protect
the work surface so that nothing
can get melted or burned.
• Use a stand or holder to hold the
iron when not in use.
• Solder can sometimes splatter.
Make sure you wear EYE
PROTECTION.
1.

33. Soldering Safety
• There are things that you must do to be
safe when soldering:
• Solder contains LEAD which is
toxic. Always wash your hands
after soldering!
• Do not solder where food will be
prepared or eaten.
• Avoid breathing the solder fumes.
• Make sure a hot soldering iron is
NEVER left unattended!
1.

34. How to Solder
1. Make sure the parts to be soldered are clean
and not corroded. Sand or scrape if
necessary.
2. Clean the tip of the hot iron by wiping it on a
damp sponge.
3. Heat the joint with the tip of the iron.
4. After the joint has heated a few seconds,
apply solder to the joint while still holding the
iron to the joint.
5. Solder will flow into the joint.
6. Remove the iron, and do not move the joint
until it is cool.
3.a

35. How to Solder
3.a

36. How to Solder
1. The finished joint should be shiny, and have
the shape of a ‘Hershey’s Kiss’. If the solder
is dull looking or ball-shaped you have what is
called a ‘cold joint’, which is not a good
connection.
2. Use diagonal cutting pliers to cut the extra
lead from the component. Hold the end of the
lead so it does not go flying, and WEAR EYE
PROTECTION!
3.a

37. How to Prevent Heat
Damage to Parts
Some parts can be damaged from too much heat.
Use a temperature-controlled iron or use a clip-on
heat sink. 3.b

38. Precautions when
Soldering PCBs
• NEVER solder a PCB that has power
applied! Unplug everything first!
• Static electricity can damage some
electronic parts. Use a grounded
soldering iron and a anti-static wrist
strap to protect the board if needed.
• Too hot an iron can cause damage to
the PC board. Use the right wattage
soldering iron: 20 to 30 watts.
3.d

39. Anti-static wrist strap

40. How to Desolder
• Everyone makes mistakes! If you need to
desolder a part, there are ways to do it.
• If it is a part in a PCB, heat the
solder joint and pull the lead out of
the PCB hole.
• Use a desoldering bulb or
desoldering braid to remove hot
solder from the PCB hole.
3.a

41. Desoldering Braid
Desoldering Bulb
3.a

42. Electronics Merit Badge
Boy Scouts of America
Module 3
Audio Circuits
2014

43. Audio Circuits
Many electronics circuits are used for
audio. Any device that makes a sound or
processes a sound signal is an audio
circuit.
Audio circuits are found almost everywhere
you look. How many can you find?

44. Audio Circuits
Amplifiers are a kind of
circuit that increases the
volume of a sound signal.
4.c.1

45. Audio Circuits
Communications circuits, like
radio, TV and cell phones, let
people communicate with audio
signals.
4.c.2

46. 4.c.3
Audio Circuits
Warning circuits, like sirens and
alarms use sound to warn
people of danger.

47. Audio Circuits
The circuit we are going to build is an
audio circuit for practicing Morse Code!

48. Electronics Merit Badge
Boy Scouts of America
Module 4
Electronic Careers
2014

49. Electronics Careers
There are literally thousands of different
careers available in Electronics. Each one
requires different amounts of training and
education.
Many people in Electronics careers got
their start in Electronics through Boy
Scouts!

50. Cable TV Technician
Installs and repairs
cable TV equipment
Education requirement: Minimum High
School diploma, with employer supplied
classes and training.
6.1

51. Electronics Technician
Builds and
troubleshoots
electronics equipment.
Education requirement: Two Year
Associates Degree, often with employer
supplied classes and training. 6.2

52. Electrical Engineer
Designs electronics
devices for others.
Education requirement: Four year BS or
six-year MS Electrical Engineering degree,
internships during college are helpful and
encouraged. 6.3