NE-2H (Neon Lamp) Specifications

Chicago Miniature has them in their catalog.

Link is at:

Good Luck,

Al

And emit quite a loud report when current exceeds a few amps.

Are there any variants that have decent (>20 years on) life?

Gee, I used to use those all the time. Maybe 90 volts to fire one and about 60 volts to drop back out - and they glow a very pretty blue when you run RF thru them...

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Thanks, Just what I needed.

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

And a beautiful violet at about 1A, though the electrodes quickly melt.

In art. , Jim Thompson wrote:

Striking voltage varies so much and so wildly with age, condition, manufacturer, etc... If it reliably strikes at 110 volts AC (peak voltage

155 volts) in the dark I would not consider it failed/defective. And they have some photoelectric effect!

Valley voltage: Varies widely with manufacturer, age, condition... Anywhere from about 54 volts to 80 volts or maybe even a bit more (well-used). I would say typically 65 volts valley voltage.

Valley current - Design for the voltage drop to be close to the valley voltage at any current from 2.5 to 4 mA. There may even be more than one valley in the 2 to 4 mA range. Secondary valleys sometimes exist sometimes at somewhat lower currents. The lamp may flicker if the current is low enough to have the electrodes not fully or nearly fully covered with glow (the glow may jump around like it does in "flicker flame" neon lamps) - you need the current to exceed that of the highest-current valley to avoid that. But have current exceeding that of the highest valley by as little as practical - current in excess of that of the highest valley results in "abnormal glow" or glow having "above-normal current density", and that causes accelerated wear on the electrodes (and the bulb being darkened by "sputtered" electrode material).

Life expectancy: At 120 volts AC, traditionally 20,000 or 25,000 hours with a 33K resistor, 5,000 hours with a 22K resistor. At 120 volts AC, a resistor of 39K or 47K usually results in current close to the main or highest valley current - going higher extends life no more than proportionately.

NE2H is sometimes AKA C2A. There is a mini-NE2H sometimes AKA A1C, which is Radio Shack 272-1102, even though the catalog claims that it is a C2A.

These are "high intensity" neon lamps, which contain nearly enough pure neon. "Standard intensity" neon lamps have 99.5% neon .5% argon, and these include NE2 (AKA A1A) and the mini-NE2 (AKA A1B, which the Radio Shack

272-1100 usually is). The color of "standard intensity" neon lamps is a "soft orange" rather than a brighter slightly reddish orange. Although argon is expected to make the glow purpler, it does this more in the main discharge column, which low pressure glow lamps having closely spaced electrodes lack. In the electrode glow ("cathode/negative glow") of a neon lamp, argon radiates pretty much only its strong infrared wavelengths, and detracting less from a yellow wavelength of neon (585 nm) than from neon's red and orange wavelengths. (My guess - but the effect of half a percent argon is definitely making the color of the cathode/negative glow yellower, as in a less-red shade of orange!) The valley current of the NE2/A1A is less than a milliamp - the traditionally recommended resistor for use at 120 VAC is 220K. The A1B "mini-NE2" appears to me to want a 330K resistor at 120 VAC. In these "standard intensity" neon lamps that have 99.5% neon .5% argon, the valley voltage is a little lower - generally in the range of 50 to 65 volts, probably usually mid or upper 50's. The striking voltage is usually under 100 volts, but varies widely with age, condition, incoming light, and frequency or whatever can effect the electric field distribution within a lamp that is trying to start. There are variants with Krypton-85 added to assist starting (look for a very slightly pinkish color, milder than usual of that of neon lamps that have had air leak into them) - strinking voltage with those is probably reasonably reliably not far from 75-80 volts, if you allow a few seconds for a beta particle to do some good within the lamp when the peak voltage is that low. And Kr-85 has a halflife of only 9.4 years - give allowance accordingly to ones manufactured a few decades ago back when this was not so politically incorrect!

- Don Klipstein ( snipped-for-privacy@misty.com)

Ok, how about an LTspice model that starts with the following parameters:

V_strike = 130V (strike voltage in fully non ionized gas) I_ionization = .5ma (threshold current between strike and hold regions) Tau_ionization = 1ms (gas ionization time constant) V_hold = 80V (Zener-like hold voltage above ionization current) R_hold = 1k (series resistance within hold current range) I_abnormal_glow = 4ma (current beyond which series resistance increases)

I think this should cover all of the parameters important to model the normal operation of a neon bulb. The decrease in voltage beyond the abnormal glow voltage rise could easily be added onto this if it were required for some reason.

• * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

• NE-2H Small Neon Lamp Behavioral Model by snipped-for-privacy@ieee.org

• Vs: strike voltage (bi-directional)

• Ii: threshold current boundary between strike and hold voltage

• Ti: ionization time constant of gas

• Vh: hold (regulation) voltage within normal current range

• Rh: on resistance within normal current range

• Ia: transition current to the increasing resistance of abnormal glow

• * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

.subckt NE-2H A1 A2 params: Vs=130 Ii=.5m Ti=1m Vh=80 Rh=1k Ia=4m Varc A1 arc 0 ; current sense Barc arc A2 I= sgn(V(arc,A2))*uramp(abs(V(arc,A2))-V(ref))/(Rh*V(abn)) Carc arc A2 5p ; stray terminal capacitance Bref 0 ref I= Vh+{Vs-Vh}/(1+V(ion)**2) Rpar=1 ; voltage transition Cref ref 0 1n ; tiny capacitance here aids convergence Bion 0 ion I= abs(I(Varc)) Rpar={1/Ii} ; measure of free ions Cion ion 0 {Ti*Ii} ; gas ionization time constant Babn 0 abn I= {Ia**2}+I(Varc)**2 Rpar={1/Ia**2} ; abnormal glow Cabn abn 0 1p ; tiny capacitance here aids convergence .ends NE-2H

Note that all static calculations involving only parameters (and not dynamic variables from the circuit matrix) are enclosed within curly braces so that they are evaluated once only as the subcircuit is first read in and not at every step during the transient analysis.

Also, note that the model has only one significant time constant and this represents the lifetime of conductive ions within the gas. Thus, the neon lamp could theoretically be represented by only two sources, one to model the ionization time constant and one to model all of the non-linear effects combined (which are not time dependent).

In fact, I found that breaking these non-linear calculations into several parts actually makes the model run faster and more reliably even though the resulting circuit matrix is somewhat larger. I suppose this is because the matrix solver requires quasi-linear behavior to get from one time point to the next, so that extreme non-linear behavior forces extremely small time steps.

I find the understanding and modeling of glow and arc discharges to be fascinating because of the unusual negative incremental resistance characteristic of arcs at low frequencies. A number of very good papers on the subject of modeling fluorescent lamps are contained within several of the IEEE power electronics conference proceedings published within the last decade. As I recall, these papers concentrated on modeling the ionization time constants and negative (V = 1/sqrt(I)) arc resistance stemming from the area and density modulation of the conductive column within the gas in the arc path. But I don't recall coming across a paper exclusively addressing the very much lower current density glow discharge processes within a neon bulb.

With a neon bulb there isn't enough current to heat up the closely spaced electrodes so the cathode operates cold and also there is no discharge column to contribute to the voltage drop. As long as some ions are already present and the surface of the cathode isn't saturated with current, the voltage required to generate additional conductors is largely independent of current and consists of what is known as the cathode fall voltage. Initial striking voltage is higher because no conductors yet exist to be accelerated by the electric field into regenerating additional conductor through collisions. The first loose electrons must either be ripped from their orbits by electric field alone or with photoelectric assist.

Once the surfaces of the electrodes are entirely covered with glow, it takes a higher energy to crowd in additional conductors and the neon bulb's normal glow voltage begins to rise with current. This is the abnormal glow region of operation and can damage the electrodes by blasting off metal atoms. Pushing the current even higher will heat up the electrodes to the point of thermonic emission, leading to a reduced on voltage as the cathode fall disappears. This is the negative resistance region of operation of an arc discharge and cannot be sustained for any length of time by a tiny neon bulb (boom!).

What this all means is that a good spice model for a neon bulb may not be the same as a model one for a fluorescent bulb or high pressure discharge lamp. An all encompassing model may be possible, but would probably be too complicated to run as quickly as a simpler, application specific model would.

Even on 240V failed neons re quite common.

[snip]

Analog, I_ionozation seems quite large... order of magnitude higher than with your NE-2 model; and gives rather bizarre behavior when used in a "multivibrator" type circuit.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

I have some OA2 (gas voltage regulator) tubes from the early 70's which have a disclaimer on the side about Krypton in them that I never understood before. I understand a little more now!

Tim.

I learned the hard way about the behavior of gas voltage regulator tubes that *don't* have the Krypton...

In 1961, I had my big-ass "toooobz" amplifier in the attic (I rented the third floor of an old house in Cambridge).

Went home to WV for a few weeks that summer and I shut down the normally always-on power supply.

When I came back I flipped the switch and ¡KA-BOOM!, every lytic went off like a rocket.

Seems the striking voltage rises when Krypton-less regulator tubes sit in the dark for a while :-(

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Jim,

If you would also like, I can repost the scan of 'The Ubiquitous Neon' from the "Electrical Experimenter's Handbook" (1969)

Great applications for the NE-2 series of indicators. Useful for everything from voltage regulators to bistable logic elements and just about everything in between.

Oppie

Hi Oppie, Sure would appreciate that! Thanks!

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

I think I even saw a "ring oscillator" once. That's like an astable, but with more than 2 stages. Haven't built one yet, however.

Cheers! Rich

I built one for my dad's BD when I was a kid. It used 3 scrap neon indicators from an old IBM mainframe, and just went blink, blink,blink... in a triangle pattern.

It sat on my dad's night stand for an awfully long time blinking away. At one point, many many years later, the bulbs grew dim, and he asked me if I could fix it for him, so I did.

Funny the things one's parent's just like... fond memories, I guess.

-Chuck

Yup. Baldwin used NE-2's in the triggering of the percussion section of a generation of their organs. The circuitry had a row of Type 47 bulbs along its length to optically bias the neons.

I read in sci.electronics.design that Oppie wrote (in ) about 'NE-2H (Neon Lamp) Specifications', on Mon, 8 Dec 2003:

How do ubiquitious neons differ from ordinary ones?

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There's a 5-stage one illustrated at

I've built it and it works well: even though 150V and 200V B+ batteries aren't around anymore 9-volts stack very nicely.

It's worth noting that the design is perfectly symmetric; with well-matched components it'll go left-to-right just as likely as right-to-left. The symmetry is broken at startup by the firing of the first and second adjacent neon bulbs. Sometimes a third bulb will fire out of sequence at startup, but after that it'll be in sequence.

I think this is an example of "spontaneous symmetry breaking". After building this neon circuit I now understand sentences in my graduate physics books like "it can be seen how the spontaneous symmetry breaking of the U(1) symmetry caused by the degenerate energy minimum of the Lagrangian (2.10) creates a pertubative theory with a massive scalar boson."

I've tried extending it to 10 neons but it doesn't run so stably there... sometimes bizarre patterns pop up seemingly at random, and other times it will run in sequence. The crosswire that "inhibits" the non-adjacent bulb from going off isn't quite so effective compared to the random ionization levels, I guess.

Tim.

They're simply *everywhere*.

-Chuck