How Do Neon Glow Bulbs Work

[Mackey]

A very frequent question amongst fans of flip clocks, can be paraphrased: "Wouldn't it be better just to replace those old orange lights in flip clocks with an LED?"

That's for you to decide, but as for me and many other collectors of vintage flip clocks, the short answer is "no". The long answer is " #$@&%*!    NO!" No it would not be better. It’d be about as better as removing the flip clock mechanism and replacing it with an electronic digital clock, - just because they’re more accurate and efficient.

The reasons that I personally continue to use the neon glow bulbs are many:
1. I want to keep a vintage clock as original as possible.
2. The warm orange glow perfectly suits these vintage clocks and it is quite pleasant at night - very easy to wake up to.
3. Putting in an LED requires a DC source - this will require installation of a converter or pulling DC off the circuit board (causing possible performance issues).
4. It's easier!
5. It's Retro.

To learn how these bulbs work, see the article The wonders of the orange neon glow lamp . In this thread I'm hoping we can add more details about these retro bulbs.

[Mackey]

More Details
There are many miniature neon bulbs types - the first five on the list below being the most commonly seen in flip clocks:

• A1B
• C2A (NE-2H)
• A2B (NE-2V)
• A3C (NE-2U)
• A1A (NE-2)
• ----
• B2A (NE-51H)
• B1A (NE-51)
• C9A (NE-2J)
• A1H
• B7A (NE-45)
• A9A (NE-2E)
• C7A (NE-2D)
• B9A (NE-48)

As mentioned in the article , the neon glow lamps use straight AC current. But it is crucial that you make sure that the proper resistor is placed in line between the bulb and the current. Only one leg of the glow bulb has to have a resistor in place. You'll have to find out what size resistor is needed by reading the specifications regarding the specific bulb that your are considering. Sometimes, online sellers include the resistors with the purchase and you will have to soldier it to the bulb properly. On some eBay listings the bulb already comes with the resistor in place.

If you're repairing a clock, you often can just simply replace the bulb (soldiering it into place) and using the resistor that is already there. However, I personally always get a new resistor and start fresh. If you use the wrong resistor for the bulb you'll either end up with a dim bulb or a bulb that is running to hot and which could cause problems, but for sure will not last as long as it would with the proper resistor.

bulb with in-line resistor in place.

Some online sources of Neon Glow Bulbs

North America
Memotronics.com - C2A Neon Glow Bulb>
Replacement Neon Lamps & Light Bulbs
All Electronics - NE-2 Neon Lamp

Australia / New Zealand
jaycar products

If anyone has additional sources, please let us know and I will updated this list.

[flipoclock]

The link for 'Jaycar', even has blue and green colours available... Would be interesting to test that, not 100% sure whether it would fit the retro feel of a vintage flip clock though.

[Mackey]

The link for 'Jaycar', even has blue and green colours available... Would be interesting to test that, not 100% sure whether it would fit the retro feel of a vintage flip clock though.

I've got a large amount of the green bulbs - vintage. They're well made and I'm thinking they'll last forever (I mean until they're used, of course). They made them well. There's a listing for blue green and red (orange) on eBay from Hong Kong which I'm going to buy ... just so I have some blue ones and I want to check the quality of my greens against new ones.

eBay - 60pcs Neon Indicator Light Sign Bulbs 4*10mm RED Green Blue

[Mackey]

This is a page from an old magazine (see full pdf). I had always assumed that the larger A1A would be brighter. Apparently not. I've been using the C2A for a while and have always be satisfied with the result. It's just not the same size as the originals. But the thing is, these days you can't find the original size bulb. I least I can't. Common bulb types include:
A1A
A9A
A3C
A1B
C2A (NE-2H)
But I do have some of the little A1C - they're actually the brightest that I have. I got them as new old stock from Poland of all places. But they're half the size of the C2A. I think all around the C2A is the way to go. It takes a readily available 30K ohm resister and the company I've used includes the resistor with the bulbs.

https://www.memotronics.com/new-box-...ree-resistors/

[davidm]

This is a page from an old magazine (see full pdf).

Some very useful info there Mackey, I've downloaded that pdf & will keep it for future reference.

I particularly liked the "Physical Characteristics" panel on page 3

If we notice our neons have suddenly darkened overnight we know that it's probably due to gamma radiation.

Or if the neons are lit without having mains power it's due to a local high intensity electrostatic or RF field.

So our neons make very handy SHTF and UFO detectors

[Bonzai Huorn]

Phosphor-coated green bulbs were used in a few 70’s flip clocks as well as one model of the Lumitime. Today you can buy them cheap in green, blue, lemon yellow (old Soviet bulbs), a sort of golden-orange, white, and very rarely, red. However, the newer phosphor bulbs seem to have a very short life. After a year or so, they become noticeably dimmer. One American brand of light switch sold in stores today features a green neon behind the bezel surrounding the switch lever. We installed several of these two years ago and only one still glows today. I believe the older bulbs were filled with argon rather than neon.

[Mackey]

Good information Bonzai

[Daddy-O]

Hi all

Further to this discussion I have a question. I have a National Panasonic RC 6001BA flip clock in good order other than the neon lamp has blown.From what I can tell from the above and the Jaycar site, I can use an NE-2 bulb with a 270kohm resistor to run it at 220 volts. My question is, can the resistor be attached to either of the pigtail leads? As I recall, resistors are non-directional so they can't be put in backwards. Sorry if this is a bit elementary but better to be sure than sorry.

[Mackey]

No.. There are no dumb questions here by gosh!!
Man, I remember needing to learn the same thing (back before flipclockfans.com).
Yes, either lead and the resistors you are working with are non-directional.

[randytherat]

Hi, where do I get a 100k Ohms 1/15 watt resistor for an A1A bulb? The bulbs I purchased did not come with them.

[Mackey]

Hi, where do I get a 100k Ohms 1/15 watt resistor for an A1A bulb? The bulbs I purchased did not come with them.

You'd do better just to go with another bulb with the resistors included. It will take you about the same amount of time.

https://www.amazon.com/Memotronics-Bulbs-Resistors-Included-Lamps/dp/B01G97X3XS

[randytherat]

Is it normal for the electrodes to be only half lit? I am using the correct resistor it came with. These are the memotronics brand and all of them are the same.

[Mackey]

Is it normal for the electrodes to be only half lit? I am using the correct resistor it came with. These are the memotronics brand and all of them are the same.

They will be half lit if you are powering them with D/C instead of A/C

[frodisman]

So I purchased this Audition 3838 clock radio and it has this green phosphor? bulb inside. For now I used a green F5 or F6 (forget off the top of my head) lamp and it works but not as bright as I’d hope. Are these bulbs even available anymore? Anyone know what it’s called? Lastly what would be the best lamp to use in its place?