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testing out a nixie?

V

Vivek G.

Jan 1, 1970
0
Hi, I have some old nixies that I want to use for a clock, unfortunately
there's no data sheet out there for them (tried googling). Is there any
way to simply test these things to find out their operating voltages?
Also, any ideas on interfacing these things to a microcontroller, since
the nixies don't start lighting up until you have at least 100 volts
running across them.

my best idea on testing them so far is to guess a good value for a
resistor to put in parallel with the nixie, to serve as a current
divider since the wanted current in a nixie is around 1-5mA.

one site i've been trying to understand so far is this one:
http://web.inter.nl.net/users/massar/ePage/neon/HowToDriveNixies.html
 
P

Peter Bennett

Jan 1, 1970
0
Hi, I have some old nixies that I want to use for a clock, unfortunately
there's no data sheet out there for them (tried googling). Is there any
way to simply test these things to find out their operating voltages?
Also, any ideas on interfacing these things to a microcontroller, since
the nixies don't start lighting up until you have at least 100 volts
running across them.

my best idea on testing them so far is to guess a good value for a
resistor to put in parallel with the nixie, to serve as a current
divider since the wanted current in a nixie is around 1-5mA.

You want to put the resistor in _series_ with the nixie, not in
parallel. If you have a 100 volt supply, I'd suggest 50 - 100 K ohms
as a safe value.
one site i've been trying to understand so far is this one:
http://web.inter.nl.net/users/massar/ePage/neon/HowToDriveNixies.html

--
Peter Bennett, VE7CEI
peterbb (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Vivek G. said:
Hi, I have some old nixies that I want to use for a clock, unfortunately
there's no data sheet out there for them (tried googling). Is there any
way to simply test these things to find out their operating voltages?
Also, any ideas on interfacing these things to a microcontroller, since
the nixies don't start lighting up until you have at least 100 volts
running across them.

my best idea on testing them so far is to guess a good value for a
resistor to put in parallel with the nixie, to serve as a current
divider since the wanted current in a nixie is around 1-5mA.

one site i've been trying to understand so far is this one:
http://web.inter.nl.net/users/massar/ePage/neon/HowToDriveNixies.html

I have thousands of some high voltage transistors, Dionics DTN-205,
which are supposed to be for driving Nixie tubes. They're rated for
150V max, and since they're in a TO-106 package, they can handle only
about 200 mW, so at that voltage it would only be a mA or so. Or maybe
a few mA no problem when saturated.

I think if I wanted a Nixie effect, I'd engrave the digits into
plexiglas rectangles, and stack them one behind the other. Then I'd
illuminate each of them with a few LEDs, driven by regular low voltage
transistors. That's how the original digital meters did their display.
But they used relays to drive the lamps, and the racket was quite
noticeable.
 
M

Miguel A

Jan 1, 1970
0
Vivek G. said:
Hi, I have some old nixies that I want to use for a clock, unfortunately
there's no data sheet out there for them (tried googling). Is there any
way to simply test these things to find out their operating voltages?
Also, any ideas on interfacing these things to a microcontroller, since
the nixies don't start lighting up until you have at least 100 volts
running across them.


Hi Vivek,

I have some nixies (ZM1210) that need 170V to start.
Once lighted they impose a 140V anode to cathode. Recommended
current for this devices is max 2mA so you have to use a
resistor depending on the supply voltage. For a supply of
200V and a 1mA current on the nixie a resistor of 60/0.001 = 60K
is adquate.
This resistor should be placed in series with the nixie, otherwise
it would not be limitting the current as expected.

A good page whith lots of information on nixie displays is:

http://www.die-wuestens.de/eindex.htm

(They also sell nixies)

good luck,

Miguel A
 
V

Vivek G.

Jan 1, 1970
0
Miguel said:
Hi Vivek,

I have some nixies (ZM1210) that need 170V to start.
Once lighted they impose a 140V anode to cathode. Recommended
current for this devices is max 2mA so you have to use a
resistor depending on the supply voltage. For a supply of
200V and a 1mA current on the nixie a resistor of 60/0.001 = 60K
is adquate.
This resistor should be placed in series with the nixie, otherwise
it would not be limitting the current as expected.

Cool, thanks to everyone for the help. I guess I was confused about the
whole series/parallel resistor thing because I kept thinking that the
100+ volts HAD to be across the nixie, ignoring the current really
needed to be driven through the circuit.

I guess the next step i'm trying to do is to use both relays or
transistors with some type of electronically controlled potentiometers
to easily switch between the nixie's numbers, and possibly do that fade
in/out technique i've seen.
 
M

Miguel A

Jan 1, 1970
0
I am also on the process of building a nixe clock,
for some time. Since I don't require fade in / fade out
effect I will use CD4017 ICs followed by a high voltage
transistor, to interface with the PIC
microcontroller. Common clock and reset lines come
from the PIC and 6 select lines are used to select which
nixie is updated. A pulse is issued to the clock line
to update to the next digit or a reset pulse is sent to
reset to digit zero. That way 6 nixies are driven with only
8 wires (PIC port B).
In Alarm mode or Adjust mode the digits have to blink to
indicate which is being Adjusted by the user. To do that
I use a series transistor in the supply line of each group
of two nixes. ON and OFF
with this transisttor does the blinking effect. (I guess
this could be used for fading too by applying a PWM).

good luck,

Miguel_A
 
S

Sal Brisindi

Jan 1, 1970
0
Hi there,
Depending on the voltage (B+) you are using for your nixie tubes, you
will need anywhere from 15k on up. Do not wire your nixie tube without
the current limiting resistor. Connect your meter in series with the
anode and measure the current and adjust your current limit resistor
until the numbers (cathodes) light up fully. There is a great nixie
group on Yahoo called Neonixie-L, do a search on yahoo and join it. Its
a great group with pictures, schematics etc...

You can go to my website and check a few of the clocks I
built. I am almost done building a 6 digit 40mm tall nixie clock.

Regards,
Sal Brisindi
www.tuberadios.com
 
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