<s>
A	O
Nixie	B-Application
tube	I-Application
(	O
)	O
,	O
or	O
cold	B-Application
cathode	I-Application
display	I-Application
,	O
is	O
an	O
electronic	O
device	O
used	O
for	O
displaying	B-Device
numerals	I-Device
or	I-Device
other	I-Device
information	I-Device
using	O
glow	O
discharge	O
.	O
</s>
<s>
The	O
tube	O
is	O
filled	O
with	O
a	O
gas	O
at	O
low	O
pressure	O
,	O
usually	O
mostly	O
neon	B-Application
and	O
often	O
a	O
little	O
mercury	O
or	O
argon	O
,	O
in	O
a	O
Penning	O
mixture	O
.	O
</s>
<s>
It	O
is	O
hence	O
a	O
cold-cathode	O
tube	O
(	O
a	O
form	O
of	O
gas-filled	O
tube	O
)	O
,	O
and	O
is	O
a	O
variant	O
of	O
the	O
neon	B-Application
lamp	O
.	O
</s>
<s>
Vacuum	B-General_Concept
fluorescent	I-General_Concept
displays	I-General_Concept
from	O
the	O
same	O
era	O
use	O
completely	O
different	O
technology	O
—	O
they	O
have	O
a	O
heated	O
cathode	O
together	O
with	O
a	O
control	O
grid	O
and	O
shaped	O
phosphor	O
anodes	O
;	O
Nixies	B-Application
have	O
no	O
heater	O
or	O
control	O
grid	O
,	O
typically	O
a	O
single	O
anode	O
(	O
in	O
the	O
form	O
of	O
a	O
wire	O
mesh	O
,	O
not	O
to	O
be	O
confused	O
with	O
a	O
control	O
grid	O
)	O
,	O
and	O
shaped	O
bare	O
metal	O
cathodes	O
.	O
</s>
<s>
Nixie-like	O
displays	O
made	O
by	O
other	O
firms	O
had	O
trademarked	O
names	O
including	O
Digitron	B-Application
,	O
Inditron	O
and	O
Numicator	O
.	O
</s>
<s>
A	O
proper	O
generic	O
term	O
is	O
cold	O
cathode	O
neon	B-Application
readout	O
tube	O
,	O
though	O
the	O
phrase	O
Nixie	B-Application
tube	I-Application
quickly	O
entered	O
the	O
vernacular	O
as	O
a	O
generic	O
name	O
.	O
</s>
<s>
Burroughs	O
even	O
had	O
another	O
Haydu	O
tube	O
that	O
could	O
operate	O
as	O
a	O
digital	O
counter	O
and	O
directly	O
drive	O
a	O
Nixie	B-Application
tube	I-Application
for	O
display	O
.	O
</s>
<s>
This	O
was	O
called	O
a	O
"	O
Trochotron	O
"	O
,	O
in	O
later	O
form	O
known	O
as	O
the	O
"	O
Beam-X	O
Switch	O
"	O
counter	O
tube	O
;	O
another	O
name	O
was	O
"	O
magnetron	B-Device
beam-switching	O
tube	O
"	O
,	O
referring	O
to	O
their	O
derivation	O
from	O
a	O
split-anode	B-Device
magnetron	I-Device
.	O
</s>
<s>
Trochotrons	O
were	O
used	O
in	O
the	O
UNIVAC	B-Device
1101	I-Device
computer	O
,	O
as	O
well	O
as	O
in	O
clocks	O
and	O
frequency	O
counters	O
.	O
</s>
<s>
The	O
magnetic	O
field	O
and	O
voltages	O
applied	O
to	O
the	O
electrodes	O
made	O
the	O
electrons	O
form	O
a	O
thick	O
sheet	O
(	O
as	O
in	O
a	O
cavity	O
magnetron	B-Device
)	O
that	O
went	O
to	O
only	O
one	O
anode	O
.	O
</s>
<s>
Glow-transfer	B-General_Concept
counting	I-General_Concept
tubes	I-General_Concept
,	O
similar	O
in	O
essential	O
function	O
to	O
the	O
trochotrons	O
,	O
had	O
a	O
glow	O
discharge	O
on	O
one	O
of	O
a	O
number	O
of	O
main	O
cathodes	O
,	O
visible	O
through	O
the	O
top	O
of	O
the	O
glass	O
envelope	O
.	O
</s>
<s>
Most	O
used	O
a	O
neon-based	O
gas	O
mixture	O
and	O
counted	O
in	O
base-10	O
,	O
but	O
faster	O
types	O
were	O
based	O
on	O
argon	O
,	O
hydrogen	O
,	O
or	O
other	O
gases	O
,	O
and	O
for	O
timekeeping	O
and	O
similar	O
applications	O
a	O
few	O
base-12	O
types	O
were	O
available	O
.	O
</s>
<s>
A	O
well-known	O
trade	O
name	O
for	O
glow-transfer	O
counter	O
tubes	O
in	O
the	O
United	O
Kingdom	O
was	O
Dekatron	B-General_Concept
.	O
</s>
<s>
Devices	O
that	O
functioned	O
in	O
the	O
same	O
way	O
as	O
Nixie	B-Application
tubes	I-Application
were	O
patented	O
in	O
the	O
1930s	O
,	O
and	O
the	O
first	O
mass-produced	O
display	O
tubes	O
were	O
introduced	O
in	O
1954	O
by	O
National	O
Union	O
Co	O
.	O
under	O
the	O
brand	O
name	O
Inditron	O
.	O
</s>
<s>
The	O
most	O
common	O
form	O
of	O
Nixie	B-Application
tube	I-Application
has	O
ten	O
cathodes	O
in	O
the	O
shapes	O
of	O
the	O
numerals	O
0	O
to	O
9	O
(	O
and	O
occasionally	O
a	O
decimal	O
point	O
or	O
two	O
)	O
,	O
but	O
there	O
are	O
also	O
types	O
that	O
show	O
various	O
letters	O
,	O
signs	O
and	O
symbols	O
.	O
</s>
<s>
A	O
related	O
device	O
is	O
the	O
pixie	B-Application
tube	I-Application
,	O
which	O
uses	O
a	O
stencil	B-Algorithm
mask	O
with	O
numeral-shaped	O
holes	O
instead	O
of	O
shaped	O
cathodes	O
.	O
</s>
<s>
Some	O
Russian	O
Nixies	B-Application
,	O
e.g.	O
</s>
<s>
Each	O
cathode	O
can	O
be	O
made	O
to	O
glow	O
in	O
the	O
characteristic	O
neon	B-Application
red-orange	O
color	O
by	O
applying	O
about	O
170	O
volts	O
DC	O
at	O
a	O
few	O
milliamperes	B-General_Concept
between	O
a	O
cathode	O
and	O
the	O
anode	O
.	O
</s>
<s>
Nixies	B-Application
exhibit	O
negative	O
resistance	O
and	O
will	O
maintain	O
their	O
glow	O
at	O
typically	O
20	O
V	O
to	O
30	O
V	O
below	O
the	O
strike	O
voltage	O
.	O
</s>
<s>
One	O
advantage	O
of	O
the	O
Nixie	B-Application
tube	I-Application
is	O
that	O
its	O
cathodes	O
are	O
typographically	O
designed	O
,	O
shaped	O
for	O
legibility	O
.	O
</s>
<s>
Nixies	B-Application
were	O
used	O
as	O
numeric	O
displays	O
in	O
early	O
digital	O
voltmeters	O
,	O
multimeters	O
,	O
frequency	O
counters	O
and	O
many	O
other	O
types	O
of	O
technical	O
equipment	O
.	O
</s>
<s>
They	O
also	O
appeared	O
in	O
costly	O
digital	O
time	O
displays	O
used	O
in	O
research	O
and	O
military	O
establishments	O
,	O
and	O
in	O
many	O
early	O
electronic	O
desktop	O
calculators	B-Application
,	O
including	O
the	O
first	O
:	O
the	O
Sumlock-Comptometer	O
ANITA	B-Device
Mk	I-Device
VII	I-Device
of	O
1961	O
and	O
even	O
the	O
first	O
electronic	B-Algorithm
telephone	I-Algorithm
switchboards	I-Algorithm
.	O
</s>
<s>
Later	O
alphanumeric	O
versions	O
in	O
fourteen-segment	B-General_Concept
display	I-General_Concept
format	O
found	O
use	O
in	O
airport	O
arrival/departure	O
signs	O
and	O
stock	O
ticker	O
displays	O
.	O
</s>
<s>
Some	O
elevators	O
used	O
Nixies	B-Application
to	O
display	O
floor	O
numbers	O
.	O
</s>
<s>
Average	O
longevity	O
of	O
Nixie	B-Application
tubes	I-Application
varied	O
from	O
about	O
5,000	O
hours	O
for	O
the	O
earliest	O
types	O
,	O
to	O
as	O
high	O
as	O
200,000	O
hours	O
or	O
more	O
for	O
some	O
of	O
the	O
last	O
types	O
to	O
be	O
introduced	O
.	O
</s>
<s>
There	O
is	O
no	O
formal	O
definition	O
as	O
to	O
what	O
constitutes	O
"	O
end	O
of	O
life	O
"	O
for	O
Nixies	B-Application
,	O
mechanical	O
failure	O
excepted	O
.	O
</s>
<s>
Nixie	B-Application
tubes	I-Application
are	O
susceptible	O
to	O
multiple	O
failure	O
modes	O
,	O
including	O
:	O
</s>
<s>
Driving	O
Nixies	B-Application
outside	O
of	O
their	O
specified	O
electrical	O
parameters	O
will	O
accelerate	O
their	O
demise	O
,	O
especially	O
excess	O
current	O
,	O
which	O
increases	O
sputtering	O
of	O
the	O
electrodes	O
.	O
</s>
<s>
Cathode	O
poisoning	O
can	O
be	O
abated	O
by	O
limiting	O
current	O
through	O
the	O
tubes	O
to	O
significantly	O
below	O
their	O
maximum	O
rating	O
,	O
through	O
the	O
use	O
of	O
Nixie	B-Application
tubes	I-Application
constructed	O
from	O
materials	O
that	O
avoid	O
the	O
effect	O
(	O
e.g.	O
</s>
<s>
As	O
testament	O
to	O
their	O
longevity	O
,	O
and	O
that	O
of	O
the	O
equipment	O
which	O
incorporated	O
them	O
,	O
several	O
suppliers	O
still	O
provided	O
common	O
Nixie	B-Application
tube	I-Application
types	O
as	O
replacement	O
parts	O
,	O
new	O
in	O
original	O
packaging	O
.	O
</s>
<s>
In	O
the	O
former	O
Soviet	O
Union	O
,	O
Nixies	B-Application
were	O
still	O
being	O
manufactured	O
in	O
volume	O
in	O
the	O
1980s	O
,	O
so	O
Russian	O
and	O
Eastern	O
European	O
Nixies	B-Application
are	O
still	O
available	O
.	O
</s>
<s>
Other	O
numeric-display	O
technologies	O
concurrently	O
in	O
use	O
included	O
backlit	O
columnar	O
transparencies	O
(	O
"	O
thermometer	O
displays	O
"	O
)	O
,	O
light	O
pipes	O
,	O
rear-projection	O
and	O
edge-lit	O
lightguide	B-General_Concept
displays	I-General_Concept
(	O
all	O
using	O
individual	O
incandescent	O
or	O
neon	B-Application
light	O
bulbs	O
for	O
illumination	O
)	O
,	O
Numitron	O
incandescent	O
filament	O
readouts	O
,	O
Panaplex	O
seven-segment	B-General_Concept
displays	I-General_Concept
,	O
and	O
vacuum	B-General_Concept
fluorescent	I-General_Concept
display	I-General_Concept
tubes	O
.	O
</s>
<s>
Before	O
Nixie	B-Application
tubes	I-Application
became	O
prominent	O
,	O
most	O
numeric	O
displays	O
were	O
electromechanical	O
,	O
using	O
stepping	O
mechanisms	O
to	O
display	O
digits	O
either	O
directly	O
by	O
use	O
of	O
cylinders	O
bearing	O
printed	O
numerals	O
attached	O
to	O
their	O
rotors	O
,	O
or	O
indirectly	O
by	O
wiring	O
the	O
outputs	O
of	O
stepping	O
switches	O
to	O
indicator	O
bulbs	O
.	O
</s>
<s>
Later	O
,	O
a	O
few	O
vintage	O
clocks	O
even	O
used	O
a	O
form	O
of	O
stepping	O
switch	O
to	O
drive	O
Nixie	B-Application
tubes	I-Application
.	O
</s>
<s>
Nixie	B-Application
tubes	I-Application
were	O
superseded	O
in	O
the	O
1970s	O
by	O
light-emitting	O
diodes	O
(	O
LEDs	O
)	O
and	O
vacuum	B-General_Concept
fluorescent	I-General_Concept
displays	I-General_Concept
(	O
VFDs	O
)	O
,	O
often	O
in	O
the	O
form	O
of	O
seven-segment	B-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
The	O
VFD	O
uses	O
a	O
hot	O
filament	O
to	O
emit	O
electrons	O
,	O
a	O
control	O
grid	O
and	O
phosphor-coated	O
anodes	O
(	O
similar	O
to	O
a	O
cathode	B-Device
ray	I-Device
tube	I-Device
)	O
shaped	O
to	O
represent	O
segments	O
of	O
a	O
digit	O
,	O
pixels	O
of	O
a	O
graphical	O
display	O
,	O
or	O
complete	O
letters	O
,	O
symbols	O
,	O
or	O
words	O
.	O
</s>
<s>
Whereas	O
Nixies	B-Application
typically	O
require	O
180	O
volts	O
to	O
illuminate	O
,	O
VFDs	O
only	O
require	O
relatively	O
low	O
voltages	O
to	O
operate	O
,	O
making	O
them	O
easier	O
and	O
cheaper	O
to	O
use	O
.	O
</s>
<s>
Unlike	O
Nixies	B-Application
,	O
the	O
glass	O
envelope	O
of	O
a	O
VFD	O
is	O
evacuated	O
rather	O
than	O
being	O
filled	O
with	O
a	O
specific	O
mixture	O
of	O
gases	O
at	O
low	O
pressure	O
.	O
</s>
<s>
Specialized	O
high-voltage	O
driver	O
chips	O
such	O
as	O
the	O
7441/74141	O
were	O
available	O
to	O
drive	O
Nixies	B-Application
.	O
</s>
<s>
LEDs	O
are	O
better	O
suited	O
to	O
the	O
low	O
voltages	O
that	O
semiconductor	O
integrated	O
circuits	O
typically	O
use	O
,	O
which	O
was	O
an	O
advantage	O
for	O
devices	O
such	O
as	O
pocket	O
calculators	B-Application
,	O
digital	O
watches	O
,	O
and	O
handheld	O
digital	O
measurement	O
instruments	O
.	O
</s>
<s>
LEDs	O
use	O
less	O
power	O
than	O
VFDs	O
or	O
Nixie	B-Application
tubes	I-Application
with	O
the	O
same	O
function	O
.	O
</s>
<s>
Citing	O
dissatisfaction	O
with	O
the	O
aesthetics	O
of	O
modern	O
digital	B-Device
displays	I-Device
and	O
a	O
nostalgic	O
fondness	O
for	O
the	O
styling	O
of	O
obsolete	O
technology	O
,	O
significant	O
numbers	O
of	O
electronics	O
enthusiasts	O
have	O
shown	O
interest	O
in	O
reviving	O
Nixies	B-Application
.	O
</s>
<s>
During	O
their	O
heyday	O
,	O
Nixies	B-Application
were	O
generally	O
considered	O
too	O
expensive	O
for	O
use	O
in	O
mass-market	O
consumer	O
goods	O
such	O
as	O
clocks	O
.	O
</s>
