The
variety of transistors and diodes in TV sets has increased a lot today,
greatly decreasing their availability in electronics stores. Although it may seem simple, often finding a replacement transistor or diode can be a chore. The
fact is that it is not so simple, it is not just to check the main
characteristics (Voltage, Current and Power) and if it is NPN or PNP, or
if it is a zener or common diode. In
addition, knowing the meaning of the encodings used in the
nomenclatures of these components also helps a lot and greatly
simplifies the work.
There are several encodings for semiconductor nomenclatures. I will address here, the most important, the most usual and directed to transistors and diodes.
The main codifications are: PROELECTRON - Europe / JEDEC - United States / JIS - Japan.
PROELECTRON
They can be started with 2 letters (Commercial use) or 3 letters (Professional use). The first letter indicates the material type:
A : Germanium.
B : Silicon.
The second letter indicates the main application:
A : Detector, mixer and switching diodes.
B : Varicap diode. (Variable capacitance)
C : Low power transistor for audio frequency.
D : Medium and high power transistors for audio frequency.
E : Tunnel diode.
F : Low power transistor for radio frequency.
L : High power transistor for radio frequency.
N : Optocoupler.
P : Photo-diodes and other radiation sensitive components.
Q : Light Emitting Diode and other radiation emitting components.
R or T : Thyristors and other control or trip switched components.
S : Low power switching transistors.
U : High power switching transistors.
X : Varistors and diodes combined.
Y : Rectifier diodes and power diodes.
Z : Zener diodes.
The third letter, if any, indicates whether the component is for commercial or professional use:
W and X : Components for commercial use.
Y and Z : Components for professional use.
Examples: BC337B
B : Silicon
C : Transistor for audio track
33 7: Transistor serial number
B : 60 Volts (No letter: 50 Volts)
BYZ10
B : Silicon
Y : Rectifier diode
Z : I use the professional
10 : Numerical series of the diode.
Small diodes can appear with the three initial letters encoded in the color of the diode body: Green body: BAV / Blue body: BAW / Black body: BAX
In
these cases, the 3 digits of the numerical series are indicated by
bands of the color code with values equivalent to the code used on the
resistors. For these diodes, the first and thickest band is close to the cathode terminal.
Zener Diode :
After the numerical series, a letter is usually used followed by the zener tension, using the letter V as a comma.
The first letter indicates the working voltage tolerance. When the letter R appears at the end, it means that the polarity is reversed.
Letter after numeric series:
A : 1%
B : 2%
C : 5%
D : 10%
E : 15%
Example: BZX79C6V8
B : Silicon
Z : zener diode
X : Commercial use
79 : Numerical series of the diode.
C : 5% tolerance in the working voltage.
6V8 : Value of the zener voltage. (In this case, the "V" represents the comma) = 6.8 Volts
JEDEC
The Jedec code basically starts with a number, followed by the letter N , plus the numerical series. The starting number indicates the number of semiconductor junctions, 1 for the diode and 2 for the transistor. The letter N stands for silicon material.
Example: 2N2236
2 : Transistor
N : Silicon
2236 : Numerical series.
1N4148
1 : Diode
N : Silicon
4148 : Numerical series.
In
the case of color-coded diodes, there can be 3 to 5 colored bands, as
shown in the table below, with no bands to indicate “1N”, the first
bands represent the numerical series and, if the first belt is black, it
will have no value. The last track is usually the letter of the suffix. The strip close to the cathode terminal has a double thickness.
COLOR - NUMERIC SERIES - LETTER
BLACK 0 -
MARRON 1 A
RED 2 B
ORANGE 3 C
YELLOW 4 D
GREEN 5 E
BLUE 6 F
VIOLET 7 G
GRAY 8 H
WHITE 9 J
JIS
It
is a coding initiated by the number 1 or 2, 1 for diodes and 2 for
transistors, followed by a pair of letters that indicate the type and
application of the semiconductor as shown in the table below. Next is the numerical series of the component.
SA : PNP to HF SJ : P channel mosfet
SB : PNP to AF SK : Mosfet channel N
SC : NPN to RF SM : Triac
SD : NPN to AF SR : Rectifier
SE : SS Diodes: Signal Diode
SF : Thyristors SV : Varicaps
SH : Unijunction SZ : Diode Zener
Example: 2SC2235
2 : Transistor
SC : NPN for RF application.
2235 - Numerical series of the component.
1SS101
1 : Diode
SS : Signal
101 : Numerical series of the component.
As
the reader can see, this subject is not limited to a brief article like
this, but the information provided here will help many colleagues when
choosing a diode or a transistor, as a replacement or for use on a TV
card.