Transcript Electronic Components

Ch4
Electronic Components
Circuit/Schematic Symbols
RESISTOR
Resistors restrict the flow
of electric current,
for example a resistor is
placed in series with a
light-emitting diode (LED)
to limit the current
passing through the LED.
CAPACITORS
Capacitors store
electric charge.
They are used with
resistors in
timing circuits
because it takes time
for a capacitor to fill
with charge.
DIODES
Diodes allow electricity to
flow in only one direction.
The arrow of the circuit
symbol shows the
direction in which the
current can flow.
Diodes are the electrical
version of a valve and
early diodes were actually
called valves.
TRANSISTOR
Transistors amplify
current, for example they
can be used to amplify
the small output current
from a logic chip so that it
can operate a lamp, relay
or other high current
device.
In many circuits a resistor
is used to convert the
changing current to a
changing voltage, so the
transistor is being used to
amplify voltage.
SWITCH
A simple on-off
switch.
This type can be used
to switch the power
supply to a circuit.
SPEAKER
Loudspeakers are output
transducers which
convert an electrical
signal to sound.
Usually they are called
'speakers'.
They require a driver
circuit, such as a 555
astable or an audio
amplifier, to provide a
signal
LAMP
Lamps emit light
when an electric
current passes
through them
BATTERY
Supplies electrical
energy.
A battery is more than
one cell.
INTEGRATED CIRCUITS (IC)
Integrated Circuits are usually
called ICs or chips.
They are complex circuits
which have been etched onto
tiny chips of semiconductor
(silicon).
The chip is packaged in a
plastic holder with pins spaced
on a 0.1" (2.54mm) grid which
will fit the holes on stripboard
and breadboards.
Very fine wires inside the
package link the chip to the
pins.
VOLTAGE REGULATOR
A Voltage Regulator (also
called a "regulator") has only
three legs and appears to be a
comparatively simple device
but it is actually a very complex
integrated circuit.
A regulator converts varying
input voltage and produces a
constant "regulated" output
voltage.
Voltage regulators are
available in a variety of
outputs, typically 5 volts, 9
volts and 12 volts.
The last two digits in the name
indicate the output voltage.
LM7805+ 5 volts
Breadboards are used for testing and
experimenting with electronic circuits.
They are very convenient since all you
have to do is plug in the components.
On the surface of a breadboard, there are
many holes for plugging in components.
The bread board has many strips of metal
which run underneath the board that
connects the component. The metal strips are
laid out as shown below:
Each strip is a connection. So whichever
components connected to a certain strip are
connected to each other.
The blue strips shown in the illustration are
usually used for connecting the batteries and
the green strips are for the components.