High-intensity lamp bulbs

I have a small high-intensity lamp in which the original bulb burned out. The original is a type #93, 12 watts, 12 volts. Not having any such bulbs available (and living some distance away from any hardware store which might have #93s), I replaced it with an automotive turn-signal bulb. It works, but I am concerned about possibly overloading the transformer in the base of the lamp. My question basically is this: What was or is so special about the #93 bulb used in these small high-intensity lamps that the manufacturer would put a warning on the underside of the lamp base to use only this type of bulb? My lamp has such a warning. I would think any 12-volt bulb with the proper base to fit the socket would work. The only thing I haven't tried with this lamp yet is using it on the high brightness position of the power switch. The bulb seems plenty bright if not too bright on low; I am half afraid to run it on high for fear of either shattering the bulb or burning out the transformer, or both. Is there any real danger of this sort of thing happening, or am I worrying for nothing?

Thanks much.

Jeff, WB8NHV Fairport Harbor, Ohio USA

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Reply to
jeffhs
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Check the current or wattage of the automotive lamp. If it's the same or less (1 A or 12 W) at 12 V, then there should be no problem.

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Reply to
Sam Goldwasser

If it dissipates more wattage than the original the transformer is at risk.

You don't say what bulb number you used . . . typical turn signal bulb is 1073 and is 21.5 watts, or a typical back up bulb 1295 at 37 watts.

Get the right bulb . . . The socket and wiring may also be at risk, but the transformer may burn out protecting them . . .

A type 7533 is 16.5 watts (license plate / dome light)

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Reply to
default

There could also be heat issues (safety from burning your house down, melting plastic), too. Given then crappy quality of many electric/electronics today, I wouldn't be surprised if an overloaded transformer would just start on fire rather than blow an internal fuse, if it even has one.

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Reply to
Andrew Rossmann

Turn signal bulbs are usually 21 watts therefore near doubling the load on the transformer.

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    Dave Plowman        dave@davenoise.co.uk           London SW
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Reply to
Dave Plowman (News)

Thanks all for the warnings. I cannot afford a fire here, as I live in an apartment building. However, I just looked at the base of the bulb I'm presently using in the lamp, and yes, it looks like a 21-watt turn-signal or other type of automotive bulb. There are no markings on the bulb as to wattage, voltage, etc.; the only markings I can see on it are "Made in China", "2G", and "T1156", but judging from how brightly it lights when used in my high-intensity lamp on "low", it must be an automotive bulb--the "T1156" should have tipped me off. I hate to think what might have happened had I inadvertently flipped the switch on the lamp base to "high"--it probably would have either shattered the bulb or cooked the transformer.

I guess I'll have to look around, either for another #93 bulb or a new lamp. The high-intensity lamp in question is over 20 years old, which could explain why I cannot seem to find the correct replacement bulb for it (the #93 bulb may be very scarce or impossible to find anymore). The newer desk lamps I've seen use quartz halogen lamps, but I don't like the idea of using such a lamp in a desktop application since the QH tubes get so hot. I've read enough horror stories about quartz halogen floor lamps (let alone desk lamps) overheating, setting curtains afire, etc. that I am now very wary of any kind of lamp using even a very small Q-H tube. I guess I'll look around for an incandescent lamp for use on the desk where my ham radio gear is located (where the old high-intensity lamp was being used before its bulb burned out, or the filament was shaken apart).

Thanks again.

Jeff, WB8NHV Fairport Harbor, Ohio USA (email addy not shown to deter spammers)

Reply to
jeffhs

Why not go to BULBDIRECT.COM. The 93 is shown at $.52 or $1.68 depending on manufacturer, and is rated at 12.8 watts. Real simple. You;ll have to pay their minimum and postage though.

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Reply to
Mike Muderick

" snipped-for-privacy@ameritech.net" bravely wrote to "All" (29 Jan 06 01:43:28) --- on the heady topic of "High-intensity lamp bulbs"

je> From: " snipped-for-privacy@ameritech.net" je> Xref: core-easynews sci.electronics.repair:356796

je> I have a small high-intensity lamp in which the original bulb burned je> out. The original is a type #93, 12 watts, 12 volts.

I think #93 lamps might be plentiful in car part stores. A #1141 would fit.

A*s*i*m*o*v

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Reply to
Asimov

Surely is possible. UL does take into account the fact that consumers are going to "do the wrong thing."

Believe it or not, transformers are frequently designed to fail-safe, they save the cost of a fuse . . .

But, I agree, safety doesn't cost that much and type 93 bulbs are far from extinct.

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Reply to
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Jeff,

These bulbs are still readily available. Any place with a good selection of light bulbs, like Home Depot or Lowes, will have them. I might have even seen them in Wal Mart. Surprising, since these lamps

are so old. They were popular back in the '70s. The bulbs aren't labeled #93 on the blister pack, just "high intensity bulb". There are only

2 types of bulbs used in those lamps: The #93, 12 V. bulb like you have, and a small 40 W. bulb that runs directly off 120V. That one has a screw base.

Mike WB2MEP

Reply to
Mike WB2MEP

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