Philips eoclick fluorescent starter

Generally a trace of a mildly radioactive substance in the discharge tube to get it started.

The soldered components before they went to the crimp system to eliminate the lead in the solder.

Jim

Like this:

ftp://jjlarkin.lmi.net/Kry_Danger.jpg

I think some NE-2 type neon lamps had a little radioactive stuff in them, too.

John

I don't recall the exact formula but believe that it was a small quantity of radon gas was added to the Neon/Argon mixture in the discharge tube. Has the effect of lowering the strike voltage. Glow discharge makes sufficient heat to close a bimetal switch. Glow is shorted out and extinguishes while lamp's filaments are warming. When bimetal element cools and opens, fluorescent lamp strikes on the inductive kick from ballast and capacitor.

Once the fluorescent is running, the voltage across is is too low to strike the gas in the starter tube again. That is until the fluorescent reaches end of life when its voltage rises to the point where the starter keeps cycling.

Lead (solder) - Possibly internally attaching leads to capacitor foils.

IIRC, that was to enable them to ionize at a reasonable voltage while in the dark.

John

"

OK, perhaps I was being overly cynical.

Sylvia.

I have seen old fluorescent lamp starters with crimping and no solder.

This reminds me of one potato chip company starting to say "no cholesterol". Potato chips fried in vegetable oils normally don't have any cholesterol.

Also, some fluorescent lamp starters don't have anything radioactive. However, some non-radioactive FS-2 ones and a few others made for use with lamps that use a ballast that does not boost voltage from 120V are sometimes unreliable at working in the dark. This gives rise to a few fluorescent fixtures that need light to start. (Not a problem with ballasts that don't need starters, such as electronic ballasts and over 99% of old-tech ballasts for lamps 3 feet long or longer.)

Radon is not used here. Its longest-lived isotope has a half-life of only a little less than 4 days, turning into Polonium-218 - which then goes through at least 4 different pathways all being combinations of 3 alpha decays and 4 beta decays to become lead-206. One pathway has one step with halflife a little over a century and another step of a few days, at least 1 other has its longest step with halflife of a few days, and at least 2 others have their longest-halflife steps having halflife of no more than minutes.

It appears to me that radioactivity being several times higher while being manufactured than while serving a customer exposes the factory workers to several times more radioactivity than necessary.

What is used: Usually Krypton-85 or Cesium-137, after that the nickel isotope mentioned in John Larkin's link.

Radon has a half-life of just a few seconds so that can't be the fill gas. (In accordance with newsgroup protocols, I'm now supposed to call you names but being the misfit that I am, I don't do that.)

A long time ago a touch of Thorium oxide was added, the purpose being for the radioactivity to establish a uniform ionization environment and thus stabilize the strike voltage. As the Cold War progressed and the nation had Kr-85 running out its ears, that isotope was substituted for the Thorium. Easier to inject a little gas than to mix the thorium oxide in with the electrode material.

The same protocol goes for neon lamps. The only minor problem is that Kr-85 has a 10.7 year half life and so if the equipment at hand is very old, the starter or neon lamp may not be reliable.

The amount of radioactivity is so low that I can't measure it with my pancake probe survey meter. I can see it on my gamma spectrometer but only with very long counts.

Regarding the lead, it's been ages since I've seen a soldered starter. Most are now crimped and/or staked to make the connections.

The lead most likely refers to the glass used in the glow tube switch. If the leads penetrating the glass look like shiny fresh copper then the leads are dumet wire and the glass is almost surely leaded glass. Dumet/lead glass is one of the most secure and enduring gas tight seals there are.

John

Anyway, cholesterol is an essential chemical that is made by the body.

Most punters would have little understanding of the significance of marketing claims. Product safety issues aside, it wouldn't surprise me if one could promote a shampoo as containing "natural ricin, extracted from the castor oil plant."

Sylvia.

Rn222 has a half-life of 3.8 days, still not enough to help a neon lamp. I've seen mention of Kr85 and tritium in neon lamps.

Krytrons plated some elements with Nickel 63.

Tritium glow thingies are cool. This one keeps us from smashing our heads on the stupid bedpost:

ftp://jjlarkin.lmi.net/Tritium.jpg

John

Mains voltage is 240 so that's not a problem.

..maybe the reference is a soldered joint; the crimp obviously eliminating the lead. Some of the designs may have a small amount of radioactive component to stabilize ionization level.

deuterium mixed with the neon

tinned leads on the capacitor.

AIUI the starter siarts out closed until the bimetallic contacts get hot enough to spring open. then the lamp comes on and the light from that should be enough for a non-radioactive glow lamp the glow is to maintain the bimetallic contacts open.

OTOH evertything's 240V over here.

radioactive hydrogen mixed with the neon

tinned leads on the capacitor.

Why don't you buy an electronic ballast to prolong the life of the lamps? They come in many sizes and shapes so you can replace almost every existing ballast.

John, What do I need to tell my computer to view your jpg images? I always get this message when I try to see them,

?file:///C:/Users/semone/AppData/Local/Microsoft/Windows/Temporary%20Internet%20Files/ Content.IE5/34ER8OEY/Tritium%5B1%5D.jpg? cannot be displayed because it contains errors. Thanks, Mikek

?file:///C:/Users/semone/AppData/Local/Microsoft/Windows/Temporary%20Internet%20Files/

I don't know. It's a simple anonymous FTP site. For some reason, some people can't see it. Maybe try a real FTP client? I use FireFTP to put stuff up there.

John