Research for a book - light bulb question

Thread Starter

OrvilleR

Joined May 9, 2019
20
Hi guys,

I'm a writer working on a novel. I know virtually nothing about circuits and I'm hoping someone is willing to help me out.

My character needs to sabotage a light bulb so that the next time the switch is flipped, it pops and blows out. In other words, the light bulb needs to not look like it's been sabotaged, but rather has naturally burned out.

This would be a regular light bulb used in a ceiling fixture.

Any ideas are much appreciated.
 

crutschow

Joined Mar 14, 2008
23,291
I believe the drill bit needs to have a carbide tip.
To make it less visible, you can drill through the base, next to the center contact.
 

nsaspook

Joined Aug 27, 2009
6,255
Hi guys,

I'm a writer working on a novel. I know virtually nothing about circuits and I'm hoping someone is willing to help me out.

My character needs to sabotage a light bulb so that the next time the switch is flipped, it pops and blows out. In other words, the light bulb needs to not look like it's been sabotaged, but rather has naturally burned out.

This would be a regular light bulb used in a ceiling fixture.

Any ideas are much appreciated.
Working on a novel? Ok, just remember your IP address can be traced.:oops:
 

wayneh

Joined Sep 9, 2010
16,102
I like this idea but wouldn't there be writing on the bulb that would reveal the trick if inspected carefully? Maybe that wouldn't be a relevant problem to the story.

Does the bulb need to break? That's more challenging than merely making it go out.
 

ian field

Joined Oct 27, 2012
6,543
Thank you! But wouldn't the bulb shatter if you use a drill on it?
There are ways of doing it - and worth the effort if you intend filling the glass envelope with petrol...……...

If you stick Sellotape on a balloon - you can stick a pin through that without it bursting, I believe there is a method of drilling glass involving some sort of tape.

I'd just use a lower voltage bulb - some you can take the numbers off with solvent, but some are etch printed. UK showmen use 110V bulbs - but I don't know any source of 65V ones that look like regular house light bulbs.

you could hide a voltage doubling bridge rectifier behind the switch plate - wouldn't take investigators long to find the evidence though.
 

Thread Starter

OrvilleR

Joined May 9, 2019
20
Thanks so much everyone! Great ideas!

Wayneh - the bulb doesn't need to break, and it's better if it doesn't. But, I would like that loud popping sound to make it seem more like it naturally blew out. Since the person who's going to flip on the light switch is going to die shortly after doing so, it shouldn't matter that there's writing on the bulb. The only thing suspicious about those bulbs would be that they're the wrong voltage, right?
 

wayneh

Joined Sep 9, 2010
16,102
...I would like that loud popping sound to make it seem more like it naturally blew out.
Letting air in will cause the filament to destruct but I've seen that take a second or more and it won't give that satisfying pop. I think the over-voltage idea is much more likely to make the light bulb act like a flashbulb.

Which, by the way, is an option. I think you can still get screw-in flashbulbs. You could identify one in a second if you inspect it, but if the room is dark and the victim hits the light switch, you'd get a flash and a popping sound.
 

Thread Starter

OrvilleR

Joined May 9, 2019
20
Ah, ok. That makes sense. I think I'll go with the bulb swap then. My character could always unscrew the bulb he put in there and put the original one back in after he commits the murder.

Thanks so much everyone! I greatly appreciate your help.
 

ian field

Joined Oct 27, 2012
6,543
Letting air in will cause the filament to destruct but I've seen that take a second or more and it won't give that satisfying pop. I think the over-voltage idea is much more likely to make the light bulb act like a flashbulb.

Which, by the way, is an option. I think you can still get screw-in flashbulbs. You could identify one in a second if you inspect it, but if the room is dark and the victim hits the light switch, you'd get a flash and a popping sound.
when I was at boarding school in the 70s - the headmaster had a secret stash of ES27 flash bulbs. The magnesium wasn't "wire wool" style like modern (ish) flash bulbs - it was a slightly crumpled sheet of foil.
 

MisterBill2

Joined Jan 23, 2018
3,847
Diamond abrasive bits and a Dremmel!
Actually a diamond drill bit and a much slower drill, so as to avoid heating. That should work fairly well if it is done closer to the base where it will not show. And then, for added excitement use a htpodermic needle to squirt something into the bulb.
 

Thread Starter

OrvilleR

Joined May 9, 2019
20
Actually a diamond drill bit and a much slower drill, so as to avoid heating. That should work fairly well if it is done closer to the base where it will not show. And then, for added excitement use a htpodermic needle to squirt something into the bulb.
What would you squirt into the bulb? And what would happen because of it?
 

jpanhalt

Joined Jan 18, 2008
7,849
I would not squirt anything into the bulb. Anything combustible could lead to an explosion. Anything not combustible won't do anything that air won't do..
 

AnalogKid

Joined Aug 1, 2013
8,099
Gasoline, kerosene, or rubbing alcohol would give three different kinds of fire reactions. Depending on the fuel/air mixture, the glass may or may not break.

ak
 

MisterBill2

Joined Jan 23, 2018
3,847
Keep in mind that allegedly this is research for a book, probably a fiction book. And of course the injecting something into the vented light bulb would cause something to happen. If the bulb simply failed that would be boring. Of course, removing the bulb and putting a bit of tape on the bottom contact will also keep it from lighting. BUT the venting will allow a very dramatic short flash of light that may even last several seconds, depending on what the writer wants to happen. The beauty of writing fiction is that it is usually not constrained to reality.
 
Top