Week 3
Electrical Circuits and Components
It’s a Radio!
Electrical current comes in
different forms depending
on the source creating the
voltage.
Current that flows in only 1 direction all
the time is called direct current (DC)
Batteries and solar cells produce direct current
Currently that regularly reverses
direction is alternating current.
generator
Power company
(Utility)
A circuit is a complete path through
which current can flow.
Any break in the circuit will prevent
the flow of electricity throughout the
whole circuit. (open circuit)
There are two basic types of pathways that
can be set up for electric current to flow.
A series circuit is connected
so that there is only 1 pathway
through which current can flow
A parallel circuit is connected
to provide each component
with its own pathway.
What is the name of a current
That flows in only one direction?
Direct current (DC)
Are these bulbs
connected in
a series
or a parallel
circuit?
Parallel
What type of
current is
flowing through
this circuit?
Direct current
Which of these
circuits is a
series
circuit?
A
A
B
Some common Components used in Electronics
It’s a Radio!
Capacitors
The function of a
capacitor is to
store and release
electrical energy.
A capacitor is made from
two conducting surfaces
separated by an
insulating material, called
the dielectric.
The property of storing electric
energy is called capacitance
Capacitance is measured in farads.
The purpose of the capacitor is
to smooth out voltage changes.
See videos about capacitors
Inductors:
Function is to store magnetic energy ,
An
inductor
is made
from a
coil of
wire.
The property of storing magnetic
energy is called inductance
Inductance is measured in henries.
The purpose of the inductor is
to smooth out current changes.
Resistors:
Function is to control the flow of current.
Resistors have a certain specified
resistance measured in ohms ()
Some resistors are variable, meaning the
Resistance can be changed. This type of
resistor is called a potentiometer,
and is the type of component used as
a volume control.
Diodes allow current to
flow in only 1 direction,
meaning it can turn an
ac current into a dc
current by stopping the
flow in the wrong
direction.
LED=Light Emitting Diode
Transistors use voltage
or current signals to
control current flow.
Transistors can be used
as either an electronic
switch or an amplifier.
Gain is the term used that describes a
transistor’s ability to amplify an signal.
Circuit board showing component parts
What electrical component is
used to oppose the flow of
current in a circuit?
Resistor
What electrical component
stores energy in an electric
field?
Capacitor
What type of electrical component
consists of two or more
conductive surfaces separated
by an insulator?
capacitor
What type of electrical component
stores energy in a magnetic field?
Inductor
What component prevents ac current
from flowing in the “wrong” direction
in a circuit?
Diode
Representations of components in a
wiring diagram are schematic symbols.
What is component 6 in the
schematic above?
Capacitor
What is component 7 in the
schematic shown above?
Resistor
Where is the diode located on the
schematic diagram above?
5, 8 and 10
What component is shown at
4 in the schematic above?
Transformer
Where is the component located
that is used to connect or
disconnect this circuit? 3
Some components are used
to prevent equipment damage
or safety hazards such as fire
or electrical
shock due
to equipment
malfunction
Fuses “blow” when
excessive current
melts a short
length of metal.
Fuses are not re-usable!
Circuit breakers
“trip” when the
current overloads.
They can be reset.
Always replace a fuse or
circuit breaker with the same
size or model to avoid creating
a safety hazard.