DIN 40719-2

Area	documentation
title	Reference marking
Latest edition	1978-06
ISO	IEC 1346-1: 1996-03

The DIN 40719-2 was valid since 1978, a total of 25 years. The labeling of the equipment was subject to a relatively simple order that was the same as in IEC 1346-1 from 1996. These standards were replaced by EN 81346 in 2010 . In practice, the old code letters are often still used, at least in electronics.

The following table is an extract from DIN 40719-2 and IEC 1346-1:

Code letter	Resources	Examples
A.	Assemblies	Amplifiers, lasers
B.	Converter non-electrical electrical	Microphone, thermal cell, loudspeaker, photo resistor
C.	Capacitors, (capacitances)
D.	Binary elements, memory	Digital IC, flip-flop, timer
E.	various	Heating, lighting
F.	safety devices	Fuse, surge arrester, bimetal release
G	Generators, power supplies	Battery, oscillator
H	Reporting devices	Optical and acoustic, signal lamp, (power LED), buzzer
K	Relays, contactors
L.	Inductors	Coil, shaft lock
M.	Engines
N	Analog components, amplifiers	Regulator, impedance converter
P	Measuring devices, test equipment	Indicating, writing and counting, pulse generator, clock
Q	Heavy current switchgear	Circuit breaker, disconnector
R.	Resistances	Fixed resistors, potentiometers, hot conductors
S.	Switch, voter	Button, coding switch
T	Transformers	Voltage converter, current converter
U	Modulators, converters	Discriminator, frequency converter, analog-digital converter, opto-coupler, DC voltage converter
V	Tubes, semiconductors	Diode, transistor, rectifier, capacitance diode, (internal LED)
W.	Transmission routes	Waveguide, antenna, cable, light guide
X	Terminals, plugs, sockets	Terminal strip, bridge (jumper)
Z	Terminations, filters, equalizers	High pass, low pass, dynamic control

Differences between DIN 40719-2 and EN 81346

If you compare DIN 40719-2 with EN 81346 from 2010, you can see that not all code letters have changed. The previous code letters are still valid for most equipment. Depending on the application of the components, the code letters may change in the new standard. For the sake of simplicity, the most important electronic components and equipment are listed in the following table with the old and new code letters:

Components / equipment	DIN 40719-2	EN 81346
accumulator	G	G
antenna	W.	T
battery	G	G
Command devices	S.	S.
Bimetal release	F.	F.
diode	V	R.
Choke coils	L.	R.
Push button	S.	S.
Pressure switch	F.	B.
Setting resistor	R.	R.
Electrostatic precipitator	E.	V
frequency converter	G	T
frequency converter	U	T
generator	G	G
Rectifier	G	T
Limit switch	S.	B.
Power / semiconductor contactor	K	Q
Heating resistor	R.	E.
Auxiliary relay / auxiliary contactor	K	K
capacitor	C.	C.
Lamps	H	E.
Switch disconnector	Q	Q
LED	V	P
Transmitter	B.	T
Measuring device	P	P
Measuring resistor	R.	B.
engine	M.	M.
Operational amplifier	N	K
Opto-coupler	U	K
Potentiometer	R.	R.
relay	K	K
counter	S.	S.
Fuse	F.	F.
Signal light / lamp	H	P
Soft starter	G	Q
Voltage converter AC	T	T
Voltage converter DC	U	T
Storage	D.	C.
Coil (inductance)	L.	R.
Power converter	T	T
transformer	T	T
transistor	V	K
Thyristor	T	Q
UPS	G	G
resistance	R.	R.
Timing relay	K	K

Note: The most common application of the component was selected for the code letter of the new standard. According to the new standard, the marking actually consists of two letters.

Web links

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Supplement 1 to DIN 40719 part 2 circuit documents June 1978