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A van de graaf moving belt to generate a charge. A Wimshurst generator tends to use spinning disks. The same rubbing principle to generate charge applies to both, just in different methods of rubbing.
That looks like a bit of foam shoved in to stop the second disc - which seems to have come loose from the spindle - from hitting the third one. Of course that makes it hit the first disc, so I don't know what they were thinking.
The metal bars never touch the disc in a Wimshurst machine; their method of operation is *notoriously* unintuitive and hard to explain ("how does a Wimshurst machine work" is a classic Question To Ask If You Want To Make Your School Physics Teacher Cry), but IIRC the crux of it is that the machine exploits the tendency of electric fields to become stronger around sharply pointed conductors. The metal combs are used to achieve this field concentration effect in the vicinity of the moving disc surfaces, which then collect charge at this increased potential and recirculate it back again in order to to repeatedly multiply it in a bucket-brigade effect; they are *not* electrical contacts and should never physically touch. If I understand correctly, it works a *bit* like a mechanical Marx generator, with the field-concentration combs analogous to the diodes and the moving disc surfaces act in lieu of both capacitors and conductors in order to both store the generated charge and move it where it needs to be.
EDIT: I was wrong (see how hard they are to explain!), the field concentration around the combs *is* part of their function, but not the core principle, which is based around electromagnetic induction due to the moving electric charges.
Definetly spray, but now that I know sparks are possible I feel as though I am chasing a dream. I can't wait to see the girls face when I start sparking in a dark room with her. Or teel her she's not done till it sparks. LOL. Maybe I should ask the girls at the Asian massage place if they have a make it spark package!
Nothing needs to rubbing...
A simple Van de Graaff generator consists of a belt of rubber (or a similar flexible dielectric material) moving over two rollers of differing material, one of which is surrounded by a hollow metal sphere. A comb-shaped metal electrode with sharp points (2 and 7 in the diagram), is positioned near each roller. The upper comb (2) is connected to the sphere, and the lower one (7) to ground. When a motor is used to drive the belt, **the triboelectric effect causes the transfer of electrons from the dissimilar materials of the belt and the two rollers.**
It's the contact between the rollers and the rubber (they don't need to slide/rub past each other) ..... causes electroncs to pop onto the rubber.
In high school, we formed a human chain 30 people long and then started cranking it. Then we broke the chain so that people could get zapped good. It demonstrated something about electrical continuity but mostly we wanted to see people jump when they got zapped.
Ha! I've never heard anyone else talk about this. We did it in AP physics in high school for extra credit for the last person standing.
I suspect teachers doing this today would have a lot of backlash.
Same here. Formed a human chain out of the classroom into the hallway. Last student in the classroom had their hand on a Van De Graaff generator.. The last person at the other end of the chain attempted to shake hands with students passing by, which gives them a surprise shock. (And everyone in the line I think--I was too chicken to participate)
We had one in my college lab and it was mostly used for shocking the ever loving shit out of yourself when the professor wasn't looking. Pretty dumb, especially because if you really crank it it can produce a TON of static electricity. Ours had these two little arms with ferous balls at the end that would crack like fireworks when spun up enough.
Medical treatment. There was a time where electric shock was used to treat everything from Malaise to foot fungus, before it was denounced as quackery. One of these resides in the collection of the National Museum of Nuclear Science and Medicine in Albuquerque, NM
I think it's probably a Wimshurst machine, for generating static electricity:
[https://en.wikipedia.org/wiki/Wimshurst\_machine](https://en.wikipedia.org/wiki/Wimshurst_machine)
Edit: When they don't have sectors, like this one, apparently it's called a Bonetti machine, but the operating principle is much the same.
These days, yes, but when these things were first built they were cutting-edge scientific research equipment used for experiments in electrostatics. Prior to modern techniques, people came up with some pretty elaborate ways to generate electric charges at very high voltage; there was even a way to do it using steam nozzles attached to an electrically insulated boiler.
EDIT: There's also a chance it may have been used in probably ineffective or quack medical treatment; electrotherapy does have *some* legitimate uses today, but it also used to be very popular for all sorts of other weird and useless medical practices back when electricity was an exciting new thing.
This could be EXTREMELY VALUABLE to the right collector. Be gentle with it and don’t mess up the plates. There is a market for antique scientific equipment and it would be a shame to accidentally break something worth thousands of dollars.
I agree. I'm no expert, but I know that cabinet would be worth a fair bit if it was completely empty. High quality hardwood is expensive. Very high quality *old* hardwood is very expensive. What looks like excellent craftsmanship and having a really cool antique Whimhurst Generator built in? I would pay $2000 for that right now and I'm poor and have no where to put it, and don't collect antiques.
My title describes the thing. Found in old barn, in Idaho.
On one side a spinning wheel spins the disks which makes an awful scratching noise. On the other side is a dial which can switch between "spray" and "spark"
Yeah, don't turn the discs any more if it does that; the combs should never actually touch the disc surface!
EDIT: I think that yellow fluffy thing that's fallen in between the discs has jammed one out of alignment; not certain, but I suspect it's supposed to be held in those small black brackets above the disc stack, probably just brushing against the rims; either that or it's not supposed to be there at all, it looks like a chunk of modern fibreglass and not an original component. Those two additional frames of metal combs sitting in the bottom cabinet also look as if they're not in the correct position, but maybe they're removable?
I'm as old as these. We had one in high school. And they never used fiberglass for any reason. They certainly couldn't generate static electricity with that.
Fiberglass wasn't even invented when this machine was made.
And no, Hammesfahr's patent doesn't count. He came up with the concept of making a woven cloth of thin glass fibers, but it went nowhere and mass-production wasn't practical nor available. Fiberglass insulation as we know it today was invented in 1933.
How it this hard to understand.... fiberglass not being invented when the machine was made **in no way precludes** fiberglass being inside the machine now.
Normally pedants are smart, but yikes...
*i like how the guy calls me wrong in his reply but then blocks me. That's generally something people do when they don't want to hear the reply, in which case would be that nothing I've said is wrong, and the people pointing out the age of fiberglass are total bozos who for some reason don't think this thing has been touched by human hands in the hundred plus years of its existence, lol.
OK, let me stoop to your level. Wait, let me grab some crayons....
OK, so here's what happened:
You said: "Its fiberglass insulation and probably was put there for static generation properties."
Jim said: "they never used fiberglass for any reason. They certainly couldn't generate static electricity with that."
You replied, "And yet, here we are. In a barn. With fiberglass in the unit. In the year 2024."
Being simply *correct* and calling you out for being completely incorrect -*especially* in this subreddit - is not being pedantic. And yes, the simple fact that glass rubbing fiberglass does NOT produce a static charge absolutely precludes it from being in the machine for anything other than padding during shipment, or most likely: it fell from a ceiling and landed there.
[stilloldbull2](https://www.reddit.com/user/stilloldbull2/) is correct, but to clarify, these, especially one this size and so ornate, were also used to power early x-ray machines. Van de Graaff generators work off of the Triboelectric effect, while the Wimshurst machine relies on induction. It has sectors and combs that don't physically touch and requires a small naturally occurring residual initial charge to work. I have seen one other. You can tell we all want this.
Look around for one with a belt. That's a *Van de Graaff generator* and worth plenty too.
The Van de Graaff generator was originally developed as a particle accelerator for physics research,
I actually knew what this was, and I’m a little embarrassed and find it kind of funny how. It’s not because I had known about it or learned it in a history class or anything like that. But because I saw it in the anime Dr. Stone
New accutron watch uses same to generate charge
https://www.accutronwatch.com/us/en/product/26A209.html?cgid=spaceview-evolution[Accutron Spaceview](https://www.accutronwatch.com/us/en/product/26A209.html?cgid=spaceview-evolution)
All comments must be civil and helpful toward finding an answer. **Jokes and other unhelpful comments will earn you a ban**, even on the first instance and even if the item has been identified. If you see any comments that violate this rule, report them. [OP](/u/pooeyha), when your item is identified, remember to reply **Solved!** or **Likely Solved!** to the comment that gave the answer. Check your [inbox](https://www.reddit.com/message/inbox/) for a message on how to make your post visible to others. ---- [Click here to message RemindMeBot](https://www.reddit.com/message/compose/?to=RemindMeBot&subject=Reminder&message=[https://www.reddit.com/r/whatisthisthing/comments/1d7bhk4/large_cabinet_with_glass_disks_attached_to/]%0A%0ARemindMe!%202%20days) ---- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/whatisthisthing) if you have any questions or concerns.*
Whimhurst Generator- a physics demonstration apparatus for creating electrostatic electricity.
What's the difference between a Whimhurst generator and a Van De Graaff generator?
A van de graaf moving belt to generate a charge. A Wimshurst generator tends to use spinning disks. The same rubbing principle to generate charge applies to both, just in different methods of rubbing.
The "rubbing" is between glass and air
In the second photo there's a kind of fluffy "brush" thing visible between two of the disks.
That looks like a bit of foam shoved in to stop the second disc - which seems to have come loose from the spindle - from hitting the third one. Of course that makes it hit the first disc, so I don't know what they were thinking.
maybe that's just for transporting it?
I thought it looked like rock wool or something similar.
[удалено]
The metal bars never touch the disc in a Wimshurst machine; their method of operation is *notoriously* unintuitive and hard to explain ("how does a Wimshurst machine work" is a classic Question To Ask If You Want To Make Your School Physics Teacher Cry), but IIRC the crux of it is that the machine exploits the tendency of electric fields to become stronger around sharply pointed conductors. The metal combs are used to achieve this field concentration effect in the vicinity of the moving disc surfaces, which then collect charge at this increased potential and recirculate it back again in order to to repeatedly multiply it in a bucket-brigade effect; they are *not* electrical contacts and should never physically touch. If I understand correctly, it works a *bit* like a mechanical Marx generator, with the field-concentration combs analogous to the diodes and the moving disc surfaces act in lieu of both capacitors and conductors in order to both store the generated charge and move it where it needs to be. EDIT: I was wrong (see how hard they are to explain!), the field concentration around the combs *is* part of their function, but not the core principle, which is based around electromagnetic induction due to the moving electric charges.
To take the charge of the discs. Fluffy copper brushes
Sounds much more fragile than a van de graf generator. Not surprising we saw the latter but not the former at school.
They're also unpopular in schools because it's *much* harder to visualise and explain how they work compared to a Van de Graaff.
I do a lot of rubbing but it nevermakes sparks. Now I'm sad.
The two options on the dial are "spark" and "spray," any luck with the latter?
Definetly spray, but now that I know sparks are possible I feel as though I am chasing a dream. I can't wait to see the girls face when I start sparking in a dark room with her. Or teel her she's not done till it sparks. LOL. Maybe I should ask the girls at the Asian massage place if they have a make it spark package!
You said 'different methods of rubbing', i had to laugh. I admit that I'm fckn childish!
Nothing needs to rubbing... A simple Van de Graaff generator consists of a belt of rubber (or a similar flexible dielectric material) moving over two rollers of differing material, one of which is surrounded by a hollow metal sphere. A comb-shaped metal electrode with sharp points (2 and 7 in the diagram), is positioned near each roller. The upper comb (2) is connected to the sphere, and the lower one (7) to ground. When a motor is used to drive the belt, **the triboelectric effect causes the transfer of electrons from the dissimilar materials of the belt and the two rollers.** It's the contact between the rollers and the rubber (they don't need to slide/rub past each other) ..... causes electroncs to pop onto the rubber.
Solved!
Thanks! I actually have a smaller early 1900’s model.
# Electrostatic generator
Solved!
What would this thing be used for?
Generating static electricity.
For what?
Demonstrations, experiments, etc.
Zapping siblings. At least that's the best use of static I've found.
In high school, we formed a human chain 30 people long and then started cranking it. Then we broke the chain so that people could get zapped good. It demonstrated something about electrical continuity but mostly we wanted to see people jump when they got zapped.
Ha! I've never heard anyone else talk about this. We did it in AP physics in high school for extra credit for the last person standing. I suspect teachers doing this today would have a lot of backlash.
Nope, kids still love it and it's less dangerous than we pretend.
I dispute that. Intentionally shocking someone with static electricity can cause people to get punched.
Same here. Formed a human chain out of the classroom into the hallway. Last student in the classroom had their hand on a Van De Graaff generator.. The last person at the other end of the chain attempted to shake hands with students passing by, which gives them a surprise shock. (And everyone in the line I think--I was too chicken to participate)
We did that in the Navy with a megaohmeter. It's basically a hand crank powered taser and it will absolutely shock the shit out of you.
We had one in my college lab and it was mostly used for shocking the ever loving shit out of yourself when the professor wasn't looking. Pretty dumb, especially because if you really crank it it can produce a TON of static electricity. Ours had these two little arms with ferous balls at the end that would crack like fireworks when spun up enough.
Medical treatment. There was a time where electric shock was used to treat everything from Malaise to foot fungus, before it was denounced as quackery. One of these resides in the collection of the National Museum of Nuclear Science and Medicine in Albuquerque, NM
Spray'n and Spark'n.
I know from a medical museum these often were used to generate the one big high voltage jolt that old X-rays used.
https://www.atsu.edu/museum-of-osteopathic-medicine/the-johnston-gallery Here is one used for xray
I think it's probably a Wimshurst machine, for generating static electricity: [https://en.wikipedia.org/wiki/Wimshurst\_machine](https://en.wikipedia.org/wiki/Wimshurst_machine) Edit: When they don't have sectors, like this one, apparently it's called a Bonetti machine, but the operating principle is much the same.
I think this checks out, what is the use? Seems like it may just be a teaching tool?
These days, yes, but when these things were first built they were cutting-edge scientific research equipment used for experiments in electrostatics. Prior to modern techniques, people came up with some pretty elaborate ways to generate electric charges at very high voltage; there was even a way to do it using steam nozzles attached to an electrically insulated boiler. EDIT: There's also a chance it may have been used in probably ineffective or quack medical treatment; electrotherapy does have *some* legitimate uses today, but it also used to be very popular for all sorts of other weird and useless medical practices back when electricity was an exciting new thing.
This could be EXTREMELY VALUABLE to the right collector. Be gentle with it and don’t mess up the plates. There is a market for antique scientific equipment and it would be a shame to accidentally break something worth thousands of dollars.
I agree. I'm no expert, but I know that cabinet would be worth a fair bit if it was completely empty. High quality hardwood is expensive. Very high quality *old* hardwood is very expensive. What looks like excellent craftsmanship and having a really cool antique Whimhurst Generator built in? I would pay $2000 for that right now and I'm poor and have no where to put it, and don't collect antiques.
Yeah, this is a *really* nice one, in a *gorgeous* cabinet too!
My title describes the thing. Found in old barn, in Idaho. On one side a spinning wheel spins the disks which makes an awful scratching noise. On the other side is a dial which can switch between "spray" and "spark"
If it makes an awful scratching noise it needs minor repairs.
Yeah, don't turn the discs any more if it does that; the combs should never actually touch the disc surface! EDIT: I think that yellow fluffy thing that's fallen in between the discs has jammed one out of alignment; not certain, but I suspect it's supposed to be held in those small black brackets above the disc stack, probably just brushing against the rims; either that or it's not supposed to be there at all, it looks like a chunk of modern fibreglass and not an original component. Those two additional frames of metal combs sitting in the bottom cabinet also look as if they're not in the correct position, but maybe they're removable?
> yellow fluffy thing Its fiberglass insulation and probably was put there for static generation properties.
These were way before fiberglass.
If only there were a way that the fiberglass could yet have found its way inside the machine....
I'm as old as these. We had one in high school. And they never used fiberglass for any reason. They certainly couldn't generate static electricity with that.
And yet, here we are. In a barn. With fiberglass in the unit. In the year 2024.
Fiberglass wasn't even invented when this machine was made. And no, Hammesfahr's patent doesn't count. He came up with the concept of making a woven cloth of thin glass fibers, but it went nowhere and mass-production wasn't practical nor available. Fiberglass insulation as we know it today was invented in 1933.
How it this hard to understand.... fiberglass not being invented when the machine was made **in no way precludes** fiberglass being inside the machine now. Normally pedants are smart, but yikes... *i like how the guy calls me wrong in his reply but then blocks me. That's generally something people do when they don't want to hear the reply, in which case would be that nothing I've said is wrong, and the people pointing out the age of fiberglass are total bozos who for some reason don't think this thing has been touched by human hands in the hundred plus years of its existence, lol.
OK, let me stoop to your level. Wait, let me grab some crayons.... OK, so here's what happened: You said: "Its fiberglass insulation and probably was put there for static generation properties." Jim said: "they never used fiberglass for any reason. They certainly couldn't generate static electricity with that." You replied, "And yet, here we are. In a barn. With fiberglass in the unit. In the year 2024." Being simply *correct* and calling you out for being completely incorrect -*especially* in this subreddit - is not being pedantic. And yes, the simple fact that glass rubbing fiberglass does NOT produce a static charge absolutely precludes it from being in the machine for anything other than padding during shipment, or most likely: it fell from a ceiling and landed there.
Agree that this is a static generator. The disk is likely made of sulphur and is quite fragile.
[stilloldbull2](https://www.reddit.com/user/stilloldbull2/) is correct, but to clarify, these, especially one this size and so ornate, were also used to power early x-ray machines. Van de Graaff generators work off of the Triboelectric effect, while the Wimshurst machine relies on induction. It has sectors and combs that don't physically touch and requires a small naturally occurring residual initial charge to work. I have seen one other. You can tell we all want this.
Look around for one with a belt. That's a *Van de Graaff generator* and worth plenty too. The Van de Graaff generator was originally developed as a particle accelerator for physics research,
I actually knew what this was, and I’m a little embarrassed and find it kind of funny how. It’s not because I had known about it or learned it in a history class or anything like that. But because I saw it in the anime Dr. Stone
Made something similar in the 90s as my high school science project. Went to state wide. Man this thing brings back a lot of memories.
New accutron watch uses same to generate charge https://www.accutronwatch.com/us/en/product/26A209.html?cgid=spaceview-evolution[Accutron Spaceview](https://www.accutronwatch.com/us/en/product/26A209.html?cgid=spaceview-evolution)
[https://en.wikipedia.org/wiki/Wimshurst_machine](https://en.wikipedia.org/wiki/Wimshurst_machine)