75,000 watt, 2.4 million lumens incandescent light bulb!

it may have never been powered

i mean to REQUIRE that many watts, just means you make a big fat honking filament, which it has

the plaque doesn;t say it has ever been used….

and it may not be intended for 120VAC, which would cut the amps

it has 4 filaments and 2 connections, if it had 3 and 3, it could run on 3phase power
but of course EDISON would not have any of that
he was a DC man

The vintage in-situ photo others have posted have a sign which lists lighting times! Probably wouldn’t get away with that nowadays, damn ’elf n safety :sunglasses:

I’d take the infinity lumens since it would sell for 1/10th the price.
This is Budget light forum after all :smiley:

==oh
huh
so it does

does not show the wires going to it

would like to see

oh well

wle

They probably ran it on 240? It needs really high current to start, but that drops off as the filament heats.

312A to run at 240
edison may have designed it to run directly off some crazy generator just for that
though the DC generators usually are not very high

would need to be 750 V to make it 100A
that might have worked

Infinity x 2.4 lumens!

BLF: Yeah but is it high CRI? I don’t want it if it’s over 5000k. How’s the tint?

I heard they made the base a left-hand thread, so no one could steal it and use it at home.

That bulb was definitely used. You can see the frame darkened at the top, and the glass as well.

The bulb was powered on.

This link from Cleveland Historical includes a photo taken in 1954 showing it powered up. It’s obviously not running at full power though. Or their definition of “75,000” watts isn’t what I’d expect.

yeah it is hardly even as bright as the overhead lights

wle

You would not want to be in the room with it lit.
The ir would roast you!

Was it used for anything or was it just for exhibition.

My first thought is Moon Tower. Moon Towers were already enough of a crackpot idea that surely someone had the even more crackpot idea for an Uber Moon Tower.

re that youtube video:
A 20kW light at full power would instantly blind a person nearby, even burn hair an skin within seconds.
Even closed eyelids would pass enough light to destroy the retina.
That not to mention the risk of the bulb exploding.
The 20kW bulb outdoors (!) seen in the video is a really dangerous experiment. Imagine a slight breeze hitting the hot glass.
Normally, these strong halogen bulbs are embedded in lights that have proper thermal management to avoid cooling shocks to the bulb.

I’m looking again at the photos of the 75kW bulb… I think it’s actually only two connections (brass posts at the base) and the rest of the bits are simply supports (middle lower support is into glass)… so although there are 4 filiments, it looks like they’re in series?

2.4mil lumens divided by 75kw = 32lm/W, which isn’t great but not actually that terrible, especially for the time it was produced.

@gravelmonkey Yeah, it’s likely that the bulb and filament were running so hot that it allowed for higher efficiency.

Remember, the hotter the filament, the more efficient the light conversion.

I wonder which flashlight will be suitable to run this bulb in!

I saw one on Amazon that claimed 99,999,000lm, and only takes 3 AAAs!

I mean, it must be true, no?