COMMON COMPONENTS LEGEND
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D2
D2
R8
D3
C1
This is a Transistor. It has a curved side and
a flat side. Match the flat side of the
transistor with the flat side of the symbol on
the circuit board and install the transistor.
This is an IC (Integrated Circuit). These
have to be installed in a specific fashion.
The two most common indicators are the
square hole of the circuit board symbol
and the notch mark on the circuit board
symbol. The square hole indicates Pin 1 of
the IC. Pin 1 is usually indicated on the IC
by a circle mark in the lower left corner of
the IC, or else the IC will have an indenta-
tion on that side. The leg below the
indentation will be Pin 1. IC sockets will
be matched up by alighning the indenta-
tion marks of the IC and socket.
This is an LED (Light Emitting Diode). It is
Polarized, meaning it has a negative and positive
side. The shorter leg of the LED is typically the
negative side. This can also be indicated on
some LEDs by one side of the edge of the LED
itself being flat. The flat side is the Negative
side. Sometimes the circuit board symbol has a
flat side which indicates the Negative hole.
Otherwise the if not marked with a + or - symbol,
the square hole is the Negative side.
this is a Resistor. It doesn’t have a polarity so it can be installed either
way. The resistor pads will look like this on a circuit board.
This is a diode. Diodes are polarized and must be installed accordingly.
Almost all diodes have a stripe on one side (typically black, silver, or
blue) which indicates the negative side of the diode.Most of the time
the diode symbol on the circuit board will have a stripe as well to
indicate how the diode is to be installed. If the diode does not have a
stripe the the arrow symbol on the circuit board will point to the hole
that the negative lead of the diode goes in.
These are polyfilm, box style, and ceramic capacitors. They are not
polarized so that can be installed either way. On a circuit board their
pads will typically look like this:
This is an Electrolytic Capacitor. Some are polarized, some are not.
General deduction of whether or not it polarized or not is a black or
silver stripe. A non-polarized electrolytic capacitor will not have a stripe.
The negative side of an electrolytic capacitor can also be determined by
the legs of the capacitor. The negaive side will have the shorter leg. The
circuit board symbol indicates the positive or negative side. If it does
not, the square pad in the symbol is the positive hole.
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