Why are you sharing 1 anode resistor across two tubes? :) Is board space
at that much of a premium?
On 3/16/2012 12:18 PM, Imbanon wrote:
First of all, thank you all for your support. Feels great to have some
people with knowledge behind my back.
So many replies since I had time to check the group last time that I
don't know where to start :)
I do not have a schematic for my design, as it is my own design that I
pretty much pull out of my head as I go. That often shown like a bad
idea, making me to change a lot of things afterwards. Just like today,
I had to rewire the whole 'spider web'. And that was the second time I
had to do it!
And I have to clear out that I have a common anode resistor for 2
tubes, making a total of 3 anode resistors for all 6 tubes. That means
that the current has to be double (resistance cut by half). I hope
that it now explains the rounded 8mA (7.74 to be more precise) on the
anode resistor. It cuts to two nixies, giving appox 3.87mA peak
current to each tube. So then 3.87*sqrt(0.267)=2mA RMS
Anyhow, I do believe that I have to use the RMS values when working
with multiplexed designs, rather than average. Just like someone
already explained why, because of the power dissipation. I really hope
it is that way :)
Well that's all for now. I hope that my setup with anode resistors is
finally done. If not - I still have another week to use all the fancy
expensive oscilloscopes! So if anyone doesn't agree with this, please
say the word :)
Cheers
On Mar 16, 9:13 am, Dekatron42<[email protected]> wrote:
Many manufacturers write that you will have to contact them for the
special curves you need when you are going to multiplex their Nixies
since they do not usually print that information in the databooks.
These sheets show you that the Nixie will have an increased turn-on
voltage corresponding to the increased current when run in switched
mode. This is the same as when a neon voltage stabilizer tube is used,
the voltage increases somewhat when the current increases, you can
check the OB2 voltage regulator tube for instance.
The curves for most Nixies when used in multiplexed mode are not
linear so if you can't find those curves you'll have to make the
measurements yourself and take into account the spread between
different Nixies to draw the curve. Some of these special curves have
a voltage span of approximately 10-30V for a certain current through
the Nixie, so there is an upper and a lower limit for the turn-on
voltage corresponding to the current used.
This book:http://www.oldtimeradio.de/BU7908.php"Electronica 171 -
Elektronische Anzeigebauelemente" by Winfired Müller contains a few of
these curves for the ZM-series of Nixies.
/Martin
On 16 mar, 00:55, Cobra007<[email protected]> wrote:
Yes, I think I mentioned "slightly" increase rather than a mayor
increase.
I have measure this on another nixie tube and came to the following
voltages:
0.5mA : 120V
1.0mA : 125V
1.5mA: 130V
2.0mA: 133V
3.0mA: 140V
4.5mA: 150V
His tube current will increase from 2mA to about 7.5mA, so according
to the above measurements, the increase in tube voltage will be
playing a role.
Michel
On Mar 16, 10:06 am, Charles MacDonald<[email protected]> wrote:
On 12-03-15 05:46 AM, Cobra007 wrote:
So it looks like your resistor is correct. The only thing is that the
voltage across the tube will slightly increase due to the higher
current, so it's not 100% correct but pretty much.
Since we are talking a Neon device, the voltage across the tube will try
to stay the same, with the current adjusting if needed. That is why
Neon bulbs were used as Voltage reference devices in days of Old.
--
Charles MacDonald Stittsville Ontario
[email protected] Just Beyond the
Fringehttp://users.trytel.com/~cmacd/tubes.html
No Microsoft Products were used in sending this e-mail.
--
You received this message because you are subscribed to the Google Groups
"neonixie-l" group.
To post to this group, send an email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/neonixie-l?hl=en-GB.
