Anyone selling IEL-0-IV or the more rare IEL-0-VI?

[Chaos Hydra]

Hi Yall,
Just by looking, I fell in love with the so called "alien" EL display tubes. Absolutely beautiful tubes! Any one here selling IEL-0-IV or IEL-0-VI (especially)? I am willing to put some big money to collect a set of those. Yall have a good day!

[gregebert]

Recently, I've seen them on Ebay so I bought a set of 4. I'm sure I saw a set of 6 about a week ago for roughly $60 US.

These things are really large, so they will make a good-looking clock.

It's a future project of mine, but I will warn you that E-L displays have a very short lifespan, roughly 500 hours. Definitely not for an always-on clock. They also require an A-C driving waveform, and definitely NOT a square-wave. Basically, they use capacitive current (i=Cdv/dt). I will likely use a triangular wave, which has a constant dv/dt.

[John Rehwinkel]

> It's a future project of mine, but I will warn you that E-L displays have a very short lifespan, roughly 500 hours. Definitely not for an always-on clock. They also require an A-C driving waveform, and definitely NOT a square-wave. Basically, they use capacitive current (i=Cdv/dt). I will likely use a triangular wave, which has a constant dv/dt.

They take over a hundred volts too. It's easy enough to get a sine wave like that with a Royer circuit with a high step-up ratio, but how do you get a triangular wave of over a hundred volts?

- John

[gregebert]

>but how do you get a triangular wave of over a hundred volts?

With a capacitive load, a constant-current source will produce a triangular waveshape. With the common electrode grounded, each segment could be driven with a totem-pole driver to roughly +100v and -100v. When I say 'roughly', I mean there will need to be some tweaking, and it will probably be somewhere between 100-150V.  Constant-current drivers are very simple to design; the challenge here is to make reliable high-side and low-side drivers. Since the operating speed is only a few hundred Hz, you could use opto-isolators to serially shift-in segment data.

The triangular waveform really isn't the end-goal; it's actually a consequence. What really matters in my opinion is the current.

[Jonathan Peakall]

Tubes!

http://www.oddmix.com/tech/circ_oscillator_neon_relaxation.html

Or you can find circuits that use tubes like the 6SN7. 100V no problem!

JOnathan

[Dekatron42]

Here is a link to a Russian website on these electroluminescent displays: http://www.155la3.ru/electroluminescent.htm a bit down you can see a few different ways to drive these. The Russians used a lot of small transformers to drive these, I used small 24V/230V 0.6VA transformers when I experimented with these displays and I learned that they don't like overtones nor anything other than sine wave as a drive signal, they quickly burn out and short circuit if you drive them improperly. You also need to use a current limiting resistor as that will protect them somewhat from catastrophic failure and save them somewhat if they are driven improperly.

/Martin

[SWISSNIXIE - Jonathan F.]

Do u mean these?
http://tubes-store.com/product_info.php?cPath=32_100&products_id=660

[gregebert]

Martin - Were you able to get the E-L display working in a project, or were you just experimenting with them ?

I stopped experimenting with mine until I have time to develop a proper driver, because I only had a 60Hz source. The segments were very dim due to the low frequency, and the only way to make them brighter at 60Hz is to raise the voltage, which would destroy the display.

[Dekatron42]

I didn't finish a clock or something like that, I just made sure that I could drive them properly and then put them away for future projects. I either fed a true sine wave signal to the transformer from an oscillator or used a square wave with a transistor driving the transformer and made sure that the output was a proper sine wave without too much distortion or over tones. Even when I ran them from a dynamotor producing a perfect sine wave at 400Hz they didn't shine anywhere near as nice as in the auction photos on Ebay - my guess is that the photos the seller's show have been adjusted (manipulated) to show a much better shine than the actual displays show, they are a lot more grainy and have a lot lower intensity compared to the ones in the auction photos. I bought a few each from all seller's I could buy from and all were grainy and shone a lot less even with a setup with the dynamotor that one seller claimed he ran them from. I don't think all of the ones I got were bad or damaged but that it is their true condition. I also read (in a test I translated with Google translate) in a Russian book that these displays age over time even when they aren't used due to their construction. The small glass encased ITEL2 displays, single segment ones, seem to work a lot better, maybe due to their construction.

/Martin

[John Rehwinkel]

> I stopped experimenting with mine until I have time to develop a proper driver, because I only had a 60Hz source. The segments were very dim due to the low frequency, and the only way to make them brighter at 60Hz is to raise the voltage, which would destroy the display.

I wonder how they'd work with modern EL driver chips (MIC4826, HV850, HV860).

- John

[gregebert]

Those devices might work, but be aware they are designed for single-element E-L devices, such as backlights. Segmented displays would need additional circuitry, perhaps triacs, to control segments individually.

The E-L drivers I looked at produced slow rise-fall square-waves; I still think a triangular wave (ie current-controlled) driver is the best. I also think that, compared to a sinusoidal waveform, a triangular waveshape would place less voltage across the E-L display and less peak-current, for a given brightness & frequency.

[Chaos Hydra]

Yeah, found those! Siberian store have have the VI but it is out of stock. Considering the difficulty of turning them on, now I am looking for ways to build a proper driver.............

[ZY]

You should also try looking at I-209 and I-195 displays. They look to be much larger than the IEL ones. You can see a few as the first few images of this google search:

https://www.google.com/search?q=I-209+electroluminescent+display&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj30a7-3rrNAhVJ1h4KHfxXBRUQ_AUICSgC&biw=919&bih=635#imgrc=_

They seem to pop up quite often on Ebay.

[gregebert]

I have 4 of the larger devices (I-195 ?), and at 75mm character-height,  they are the largest displays in my collection. Much larger than my nixies.

I'm still puzzled about the drive-current; supposedly these are capacitive loads, so at a given frequency & voltage you should be able to calculate the current.  For sinusoidal waveforms, the peak current should be V/(2*pi*f*C).

After measuring the segment capacitance of my device (ranges from 95p to 460pF depending on segment length), and calculating the current at 400Hz for all segments, I come up with 1.6mA. But the datasheet says 4-12mA, so I'm not sure what the discrepancy is.

I dont have a suitable driver yet, and I've only taken a quick look at 60Hz / 150Vrms. The segments were very dim. I wont do any further work till I have a decent driver, then I'll post my findings.

[SWISSNIXIE - Jonathan F.]

Ebay auction 191888892377 has the IEL-0-VI