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On 10-07-31 10:41 AM, figureloop wrote:

I have a Heathkit model IP-17 power supply that does +400VDC 0.1A and
-100VDC 1mA. It uses 2 of 6L6 tubes. You might be able to find the
schematic on the web.

If tying to build one of these, the 6L6 heater needs a well insulated transformer. The H-K limit of a 6L6 (or most simalar tubes) is not 400V. The old tubes could take some abuse but the modern ones might not. If you use a separate filament transformer and tie the Cathode to the center tap, this will not be an issue.

Horizontal output types would work as well, like a 6DQ6 or its many friends.

--
Charles MacDonald Stittsville Ontario
cmacd@... Just Beyond the Fringe

No Microsoft Products were used in sending this e-mail.

Who prefers all the same size digits?

Who prefers smaller seconds?

Who doesn't care as long as it has numbers glowing orange?

Yes, to all of the above !

I like all of those presentations, but the main goal is the overall presentation, including what type of case it goes into. I've even mixed end view (IN-4) with side view (ZM1032) tubes in my 1st nixie clock. Its a 4 digit (hh:mm) animal.

Here I go on my common rant again: I still want to see more case varieties that just 6 tubes sticking straight out of a rectangular box. And if you think you're skills aren't up to snuff, to build something spiffy, you can always used a 'found item' (or found object), and work the tubes into that. Around the time I joined this group (2003) there use to be some friendly competition on making clock cases. I haven't seen too much of that lately. Way too many rectangular boxes with tubes sticking out of the top. </rant>

Hi:

I'm inclining toward making some future Nixie clock designs follow this pattern, mainly to conserve the big expensive tubes.

I'd prefer if the size ratio could be kept to about 1:0.66, but I think I'll have to settle for 2:1, such as 30mm digits for HH:MM and 15mm digits for SS.

Who prefers all the same size digits?

Who prefers smaller seconds?

Who doesn't care as long as it has numbers glowing orange?

--- In NEONIXIE-L@..., michail1@... wrote:

I have a bunch of Russian and Chinese tubes. The china are terrible.
You would even think they were used and suffering from cathode poisoning (and
maybe they are), but many do this within a month. I just chalk it up as a
China problem so that I don't get upset about it.

Note about your IN-18 tubes. I have purchased and sold many factory
sealed boxes before. I have noticed a huge difference in tubes appearing used
and new in the same box. So, although you didn't purchase from me, it is
possible you did not get used tubes. I am still amazed at how many (within
the same batch/same box) have tubes with the Digit 1 blue spots. Also
pretty amazing is the height difference in the manufacturing size of the glass
envelope (up to 4mm range) -- again within the same batch (all matching
number of prod dates and OTK, etc.


Michail

Thanks for the comments, Michail.

About the IN-18. I wrote a post a few months ago about these. Basically I see three signs of use on the IN-18:

1. darkening of the insulating spacer washers on the support rods between the digits.
2. darkening of the mica support disks (mostly the darkening appears on the top mica disk).
3. darkening of the glass near the rectangular openings in the anode cage on the left and right sides.

I think that #1 can occur just with factory burn-in and test procedures.

But I would be surprised to see darkening of the glass unless many hours of use had occurred.

The mica disks I'm not sure about. I have some Z566M that have darkened mica and significantly darkened ceramic washers. These were also supposed to be new, and Jan at Ask Jan First states that they are new. I tend to believe him.

Perhaps you can tell us if new sealed boxes of IN-18 show darkening observation (as described above):

#1 ?
#2 ?
#3 ?


Thanks.

--- In NEONIXIE-L@..., John Rehwinkel <jrehwin@...> wrote:

Oh, I hadn't even noticed the analog meter! That is indeed a nice design!

- John

Oh yes, and it went for 70EUR... What a shame.

Jens

Actually, the combination of both analog and digital readout is quite
nice.

Oh, I hadn't even noticed the analog meter! That is indeed a nice design!

- John

[edited by A.J. - please trim quoted material]
--- In NEONIXIE-L@..., "figureloop" <crobc@...> wrote:

I am just getting started with the MAX1771 myself. I have done some other SMPS work and some SPICE modeling as well.

It is likely that the 1771 can be scaled up to high power levels. The limiting factors will include inductor core saturation and MOSFET drive capability. Ie., to get more power, you may need to insert an additional high-current MOSFET gate driver. And the inductor needed will be larger. Inductor design is non-trivial. There aren't many high power inductors suitable for flyback available commercially. Once you get over 10-20 watts, you need to start picking cores and winding custom. So you need a low loss high frequency core material.

Also, a straight boost topology such at the 1771 doesn't scale well to huge voltage boost ratios. At some point it becomes more efficient to use a flyback topology, which employs an additional winding on the inductor. That keeps the voltage stress on the MOSFET lower, as well as loosing less energy to the drain capacitance each cycle. But then the flyback transformer design is even more tricky. Winding proximity effects become a significant efficiency bugaboo.

If you don't need it to be small or highly efficient (though it is wise to try to be efficient these days), such as for a development power supply, you could also consider a linear regulator based on 6L6 tubes or even transistors.

<snip>

Thanks for the reply. Unfortunately, I want the supply to be both small and efficient, so I keep coming back to the 1771 as the best choice (even over a 555). It's a finicky IC, and even pitted against other SMPS's, component selection is of the utmost. I went over the spec sheet again, and it's limited to 24w dissipation. That's nothing to sneeze at, but it does put a pretty firm restriction on the output tubes to be used in an audio circuit.

I'm going to go ahead and attempt to build one that will give me about 325v at 50-60ma. I can still run a pair of 6v6 or EL84 with this (and of course Nixie pentodes and the like), and in the long run it will be cheaper and easier than custom transformers.

I'll put a BOM together and will post it before I order any parts for critique from those who know more than me as well as for anyone else who may find a use for a HV 1771 circuit.

--- In NEONIXIE-L@..., John Rehwinkel <jrehwin@...> wrote:

Mirrored scale? I thought we were talking about the nixie multimeter

on ePay! A nixie display with a mirrored scale would be pretty, but
possibly tricky to read. However, a mirror behind an IN-13 might be
interesting.

Well yeah I was. In the German description it says "Spiegelskala" i.e.
mirrored scale. I think in the pictures it is just not noticeable, or
maybe the mirror is a little tainted ;-)

Actually, the combination of both analog and digital readout is quite
nice.

Jens

--- In NEONIXIE-L@..., "jensboos" <neuss.boos@...> wrote:

--- In NEONIXIE-L@..., "Tidak Ada" <offline@> wrote:

The combination CVM plus C and L measurement will bw hard to find in a nixie
modell.
In that time LC meters where separate instruments.
I think you can better look for a nice Digital Multimeter (Volts/Amps/Ohms)
and eiter a LCR bridge or a digital LCR meter.

That's what I have been afraid of ;-)

May me you can find on at a ham fest. Hier die Terminenkalender für Hamfests
in Deutschland, Belgien, Niederlande und Frankreich: [
] (Deutsche sprache)

Oh thanks for the link, Eric. I am living in Aachen, Germany, so I technically could not be nearer to both Belgium and the Netherlands. Lucky me.

The VOM, you missed looks a nice instrument from a well known manufacturer.

Tell me about it, I espeially liked the very small dimensions (nearly as my Rigol digital scope) as well as the mirrored scale.

Hi Jens, Gossen is a well known German manufacturer of analoge measuring instruments. Also exposure meters for photograpy. Actually I did not know they entered the digital aera.
UNIGOR is a VOM made by Gossen and used widespread. It is a verry robust intrument, even 'student proof'....

When you live in Aachen, jou must perhaps know the Ham-fest "Dreil?ndertreff" in the polytechnical school at Roter Erde (East side of Aachen) I was there several times and liked it much.

Also the big ham-fest in Rosmalen (Near Den Bosch, Netherlands) will be a good goal for you. Not to far to travel.

I admire your NIXIE collection, since I am a tube collector too.

eric

The VOM, you missed looks a nice instrument from a well known manufacturer.

Tell me about it, I espeially liked the very small dimensions (nearly as my Rigol digital scope) as well as the mirrored scale.

Mirrored scale? I thought we were talking about the nixie multimeter on ePay! A nixie display with a mirrored scale would be pretty, but possibly tricky to read. However, a mirror behind an IN-13 might be interesting.

- John

--- In NEONIXIE-L@..., "quicklynamed" <quicklynamed@...> wrote:

Hello,
I'm a noob to SMPS (really IC's in general) but have long been a hi-fi and valve guitar amp hobbyist. I've been doing my best to comprehend the Max1771 (), but it's a steep learning curve (not to mention one of the most involved data sheets I've come across). What I'm trying to understand is if I could safely run Nick DeSmith's circuit (see links-->power supplies--->SMPS or desmith.net) at up to 400v, 60-70ma or more? I'm tired of ordering one-off transformers for prototypes and would love to be able to build a HV SMPS so I can simply adjust the output for a particular design.

Do I understand correctly that the Max1771's output abilities are simply dependent on the specs of the passive components, diode, inductor, etc?

Sorry if this has been addressed--I've tried my best to scroll through old threads. Thanks for your help (and a big thanks to Nick DeSmith for getting me interested enough to sign up at this forum). Eric

Hi,

I am just getting started with the MAX1771 myself. I have done some other SMPS work and some SPICE modeling as well.

It is likely that the 1771 can be scaled up to high power levels. The limiting factors will include inductor core saturation and MOSFET drive capability. Ie., to get more power, you may need to insert an additional high-current MOSFET gate driver. And the inductor needed will be larger. Inductor design is non-trivial. There aren't many high power inductors suitable for flyback available commercially. Once you get over 10-20 watts, you need to start picking cores and winding custom. So you need a low loss high frequency core material.

Also, a straight boost topology such at the 1771 doesn't scale well to huge voltage boost ratios. At some point it becomes more efficient to use a flyback topology, which employs an additional winding on the inductor. That keeps the voltage stress on the MOSFET lower, as well as loosing less energy to the drain capacitance each cycle. But then the flyback transformer design is even more tricky. Winding proximity effects become a significant efficiency bugaboo.

If you don't need it to be small or highly efficient (though it is wise to try to be efficient these days), such as for a development power supply, you could also consider a linear regulator based on 6L6 tubes or even transistors.

I have a Heathkit model IP-17 power supply that does +400VDC 0.1A and -100VDC 1mA. It uses 2 of 6L6 tubes. You might be able to find the schematic on the web.

My first Nixie power supply was an overly complex zero voltage switching (ZVS) flyback design created by a guy named Harry Delamano from the sci.electronics.design newsgroup. It used the UC3843A controller IC. I did some tweaking to it and wound my own flyback transformer. A big pain in the neck. Not something I want to repeat for a large number of projects. So that's why I'm going to switch to the MAX1771.

--- In NEONIXIE-L@..., "jensboos" <neuss.boos@...> wrote:

--- In NEONIXIE-L@..., John Michaud <greyfox1143@> wrote:

So are these Chinese (SZ-8) tube plentiful? They seem clear but I would bet they don't have Hg in them.
Sent from my iPhone

Hmm I reckon they are, but a great deal of them is of very poor quality. I have bought 8 of these from a batch of 25, and 3 of my 8 show serious abnormalities in construction, i.e. the pins are not centered, see for yourself:

Interesting. These are the first tubes I've seen which have worse quality than the Russian nixies. The Russian's aren't awful, just not as neat and polished as western ones. In particular, the popular IN-8 are rather ugly. That's why I've focused on German and US made tubes, since I'd like to sell some clocks when I retire, and I think visual quality is a big deal.

I'm still a bit annoyed that about 50% of the "new" IN-18 that I bought appear to have many hours of use on them. I don't think I will purchase more of those unless I am sure they are new, which is nearly impossible.

I have a bunch of Russian and Chinese tubes. The china are terrible.
You would even think they were used and suffering from cathode poisoning (and
maybe they are), but many do this within a month. I just chalk it up as a
China problem so that I don't get upset about it.

Note about your IN-18 tubes. I have purchased and sold many factory
sealed boxes before. I have noticed a huge difference in tubes appearing used
and new in the same box. So, although you didn't purchase from me, it is
possible you did not get used tubes. I am still amazed at how many (within
the same batch/same box) have tubes with the Digit 1 blue spots. Also
pretty amazing is the height difference in the manufacturing size of the glass
envelope (up to 4mm range) -- again within the same batch (all matching
number of prod dates and OTK, etc.


Michail

Hmm, sounds like they may have been some version of the HDSP-2000?



These are Hewlett Packard 5x7 displays, four digits, in a small 12 pin ceramic package with a glass lid. They have built in 14 bit shift registers but no on-board character generator, so you can light up the pixels in any combination desired. HP made a myriad different versions of this display, in a variety of different package styles and LED colors.

--- In NEONIXIE-L@..., "Tidak Ada" <offline@...> wrote:

Hallo Jens,

The combination CVM plus C and L measurement will bw hard to find in a nixie
modell.
In that time LC meters where separate instruments.
I think you can better look for a nice Digital Multimeter (Volts/Amps/Ohms)
and eiter a LCR bridge or a digital LCR meter.

That's what I have been afraid of ;-)

May me you can find on at a ham fest. Hier die Terminenkalender für Hamfests
in Deutschland, Belgien, Niederlande und Frankreich: [
] (Deutsche sprache)

Oh thanks for the link, Eric. I am living in Aachen, Germany, so I technically could not be nearer to both Belgium and the Netherlands. Lucky me.

The VOM, you missed looks a nice instrument from a well known manufacturer.

Tell me about it, I espeially liked the very small dimensions (nearly as my Rigol digital scope) as well as the mirrored scale.

Jens

--- In NEONIXIE-L@..., John Michaud <greyfox1143@...> wrote:

So are these Chinese (SZ-8) tube plentiful? They seem clear but I would bet they don't have Hg in them.
Sent from my iPhone

Hmm I reckon they are, but a great deal of them is of very poor quality. I have bought 8 of these from a batch of 25, and 3 of my 8 show serious abnormalities in construction, i.e. the pins are not centered, see for yourself:



Jens

[edited by A.J. - please trim quoted material]
On Jul 30, 2010, at 4:12 PM, "figureloop" <crobc@...> wrote:

--- In NEONIXIE-L@..., "cagamba" <cagamba@...> wrote:

<snip>

So the future hinges on Russian tubes, which is a bit unfortunate since their visual quality is poorer vs. western tubes (though IN-18 are actually quite appealing). If there are many thousands, then perhaps they may be purchased in quantity well into the future. If not, then future Nixie enthusiasts will have to scrounge tubes from old equipment, perhaps even current generation retro applications like clocks, for tubes for new projects.

<snip>


So are these Chinese (SZ-8) tube plentiful? They seem clear but I would bet they don't have Hg in them.
Sent from my iPhone


[Non-text portions of this message have been removed]

--- In NEONIXIE-L@..., "cagamba" <cagamba@...> wrote:

What do you think will be the future of this hobby? Some thoughts: Do you think it will stay pretty much the same or will things change a lot? Prices of tubes, will they go up or down? Any new developments, useful chips, things becoming easier? New ways of doing things? Shortage of important parts such as ICs? Tubes in extinction? A lot of people joining the crowd? Other uses besides (mainly) clocks? Some unexpected flood of NOS IN-18 tubes on the market, bringing prices down to 3 dollars apiece? LOL

Just a few questions, what's in your neon crystal ball?

Marco
(yeah, bored)

US tubes are very scarce. 600 NL840s at Sphere's have diminished to just 23 in less than a year. Those may very well have been the last batch of National tubes in quantity that will ever appear. There are some smooth tops at Sphere's, which are way expensive. I tend to pay little attention to end view tubes, but I don't see any quantity of those.

I'm not sure how many more European tubes exist. They are not seen much on Ebay. Only Russian tubes. Russian tubes are the big mystery as to how many are in stockpiles, and what is the true status of large tube supplies (IN-18).

So the future hinges on Russian tubes, which is a bit unfortunate since their visual quality is poorer vs. western tubes (though IN-18 are actually quite appealing). If there are many thousands, then perhaps they may be purchased in quantity well into the future. If not, then future Nixie enthusiasts will have to scrounge tubes from old equipment, perhaps even current generation retro applications like clocks, for tubes for new projects.

It would totally blow my mind if someone managed to put new tubes into production. Though it has happened for the 6L6 beam tetrode. I suspect that the 6L6 market dwarfs the esoteric Nixie however.

It seems the trend is toward every sort of display, except perhaps for the common alarm clock and some industrial automation equipment, to have LCD graphic displays or custom VFD or LCD displays.

Interface semiconductors trend toward increasing high level functionality integration. Simple drivers are becoming obsoleted.

I am planning some VFD clock designs and settled on cascaded 20-bit serial-in to parallel-out high voltage source driver chips as being the most cost effective for a flexible "universal" VFD driver board. Also, there are 3 manufacturers making these: Supertex HV5812, Allegro A6812, and Maxim 6921, all pin compatible.

Well at present, Allegro is discontinuing theirs:



The Maxim ones are available but rather expensive for designing in to projects intended for sale. I am buying up my supply of Supertex ones before they may become obsolete.

It should still be possible to build drivers with discrete transistors for the foreseeable future, though. I tend to go with discrete drivers for my Nixies.

Perhaps future enthusiasts will be forced to render LCD graphic image Nixie tube clocks!

Still available?on eBay, see item 110564447144
?
/P



De: samwibatt samwibatt@...
Objet: [NEONIXIE-L] Re: 14-/16-segment LED's with magnifying cupole and NO ascii rom?
?




Do you mean displays like this:



I found those on eBay a few years back, not sure if there's any reliable supply of them to be found. As I recall they're multiplexed and have no character ROM.

--- In NEONIXIE-L@..., "marta_kson" <marta_kson@...> wrote:

Have there ever been manufacured any 14- or 16-segment miniature alphanumeric LED displays with magnifier cupole that does not have an integrated ASCII-ROM?

IMHO one of the most fascinating LED's ever made, but all I know of have that limiting factor with the damn character generator that can not be bypassed.

.

How about the MAN2185?



Manual multiplexed control, no internal driver circuits, and you can stack them horizontally to make displays as long as you want. They are not very common though, you might have to wait a while on Ebay for one to come up for sale.

Richard Kline
www.decadecounter.com