Magnetic Ballasts

[Thomas]

Reading all of this saved me. The word Tombstone solved my issue. Sample in cart and I will refine later when I rip it down. It is a 2 U bulb 24 inch square kitchen light.

[Ralph Mowery]

About 20 or so years ago , probably more now, the greenies complained about the mercury in the tubes so it was reduced. This made the tubes harder to fire off at low temperatures.

I don't know if they make any tubes especially for the low temperatures or not.

[TimR]

Possible the jiggling makes contact, but maybe also the ground isn't good enough.

After the tube lights, the current is going end to end. But until that happens, on some fluorescent circuits, the current goes end of tube to ground by capacitative connection. As the tube warms the current goes farther down the tube until it completes the end to end connection.

So maybe when you're handling tubes you're adding some parasitic ground connection.

[gfretwell]

Just touching a fluorescent tube will make it light, no matter if it moves at all. I assume there is some capacitive coupling going on there. Incandescent lamps are AM Fluorescents are FM.

[danny burstein]

Nope. Cold temperatures have _always_ been an issue with starting them. Hence the higher output "low temperature" ballasts.

Not since at least 1960's - the decade I started working in this field.

Note there _are_ a segment (or were... it's rapidly fading out) of "high output" [a] and "ultra high output" tubes (and associated ballasts) deigned for low temperature.

And... used in ... supermarket refrigeratures/freezers and also outdoors.

While a "standard" tube is roughly 10 watts/foot, the high output ones were something like 15watts/foot and the ultras something like 25. (Don't recall the exact numbers offhand).

This both gave more light output per foot (not quite on an exact linear improvement, but close) AND also made them warmer, so kept them working in cold environments.

Oh, and there were also plastic sleeves you could slide onto the tubes. These were _mandatory_ in food processing areas to prevent glass breakage, but also served to insulate them so they could work in colder temperatures.

(And you could also find tubes with an extra glass tube around them, giving you that insulation built in, so to speak). [a] initially these were called "high efficiency" based on more light per foot, but 1970ish, when actual energy efficiency (lumens per watt) was becoming an issue, people were getting confused... so "high output" was the new name.