I recently learned that variac brushes are not like motor brushes. They're made of a particular variety of carbon that is very conductive in the vertical direction, but not so conductive in the horizontal. This makes it particularly good at carrying current without shorting adjacent windings. It also makes spare brushes super expensive, because variacs are not quite so widely manufactured now that we have VFDs and similar technologies for controlling power.
The thing that always amazes me is that series wound motors run at such an over speed don't have their armature windings thrown out due to the speed. Just shows how well theyre made even in these sadly cheap times.
+syhooverman Actually DC (and so-called "universal") motors can self-destruct if run without any load. That's why they usually connect a fan (a fan blade) to it to make sure it never runs without a load.
April 3rd 2020 according to the news..." World on lockdown because of Coronavirus!" Is it as bad as they say? I don't know. I'm at home like most people & TH-cam suggested I watch this... TH-cams A.I. is on overload because, this video is from 8 yrs ago. but its good to see him again! :-)
Btw for ya guys who would like to know the variac maker :P CMV 28E-1 | Carroll & Meynell that is the exact model took me a while to figure out the maker
If you drive the 110v connection on the variac it does sort of work as you can see, however the core will probably run into magnetic saturation, fine for short periods but for a long time might well burn out the windings. All transformers have a higher magnetic field density when they are off load, this is why you can hear photons variac buzzing when off load, but is quiet when on load when the magenetic density is less. Microwave transformers are similar, they are designed to be on load all the time supplying the magnetron (except while its warming up) so the manufacts cut on the amount of iron core, if you run them off load they will saturate and eventually burn out.
It would be a spectacular bit of viewing. There probably would not be enough inductance on that short a section of winding so the variac would probably fail in dramatic style. There also would be a very high voltage on the output for the time it is working. Possibly 1,000v or so. It would probably be arcing before it begins to combust. We need a video of this!
Hi Photon! I tried this with very small variac (2A) and it worked. I had input voltage of about 30V and I got 230V output when the input current was 2A with no load. Of course this wasn't at the middle point but somewhere at 1/10 of winding or even less. Thank you for showing this! Best regards, Electron
Greetings From Australia Photon! I was wondering, how do old school microwave ovens go when grossly overvolted? You know, the no microprocessor type with a twist around mechanical timer. I reckon you ought to give one of those a thrashing :) Pick one renowned for having a highly reliable magnetron so it will take more abuse
Depends on the use, soldering also makes them more brittle so they will break more readily if exposed to vibration or movement over the longer term, at least according to Google.
It’s always best to crimp and solder the wires. There is absolutely no question about it. It’s makes for a great connection (mechanically and electrically). solder does not tend to be brittle. Good quality lead solder doesn’t anyways.
The solder itself is fine, but (according to a number of accounts, I have not done my own comparison) the solder can have a tendency to wick up the wire away from the crimp joint, and if this happens, the point where the solder stops can be placed under stress and the metal wires can fatigue over time and break away. It's well worth looking in to if you're crimping joints because I never would have considered things like this as possible issues.
Him "This is the inside of a variac." Me: "Oh that's neat" Him: "that's where the 240 mains comes in and there's the windings that we can tap for the output" *taps windings with ball point pen* Me: "cool, cool" Him: "I have it attached to a vacuum cleaner so you can hear it power up" *Jet engine noises* Me: 0_o "It was on and powered this whole time connected to 240vac?!?!?!? Dafuuuq?"
very cool, I didn't think that CFL would take that much voltage, be very careful around CFL's when they blow the mercury gets out, make sure you have good ventilation.
You sir are a very brave man. I have seen things on your channel I never want to experience in real life. Not only is it such a frightening thing electricity is, it also a primeval urge to study and look at it. And after being electrocuted a couple times, I am very wary of electricity. I even put a transformer in my mouth once as I wanted to see what electricity tasted like. Was a 240 volt stepped down to about 12 volts / 2 - 5 amps for a electric piano. Man my heart hurt like crazy. My respect to you, and thank you for showing us the dangers of electricity, and how to respect it.
wonniewarrior the fact that even 0.5 amps is more than enough to stop a human heart, you are extremely lucky to be alive, especially considering you could actually feel its effect on your heart at the time.
I love when you manage to turn the incandescent bulb into a discharge lamp as the filament opens! I have found that on a lot of R-30 and R-40 type incandescents, they can suffer a weird fault where the filament opens but it continues to sustain through a noisy buzzing arc. Turn the light off and it's done for good, but sometimes it'll stay on for DAYS in that arc state.
That's a little compartment, and when opened, there's a spare carbon brush in there which would then be attached to the pick-up arm in replacement to the one already on there. When I got my variac, I got curious and opened the little compartment to find a replacement brush in there. It's only big enough for one brush, so it's not as if I could store a whole stash of them in there. :-D -BoomBoxDeluxe.
I should have watched right through before posting (!) - it seems there is more margin built-in than I expected! Hard to imagine why they build in so much 'magnetic reserve' unless they design with low flux to minimise iron losses for continuous operation - and for a toroid, the main exit route for heat from iron losses is out through the copper windings.
A ballast is any current limiting device. easiest ones to get hold of are flouro ballasts (18/36 watt) murcury vapor (100/250/400/1000 watt) the size you need depends on what you are doing. To hook up, you run it in series with the active (hot) connection. anything on the other side of the ballast will be limited to the ballast's rating (even short circuits) -- warning tho, everything is reference to earth unless you isolate. RCD's (safety switched) are a must as well as the one hand rule.
Interesting vid - can I suggest that over-volting only works if it is within the magnetic design limits of the variac. Like any metal cored transformer, above a certain level of 'volts per turn' the core will saturate and the inductance collapses, causing runaway current and overheating. A ballast just drops the voltage down so you still won't get much higher than the voltages written on the variac! And of course over-current will burn the brushes.
Now thats a super variac :-) They are dam expensive, a multi tapped auto transformer, nice. And i thought you were going to put a reversed 440 to 240v transformer on the output. Great vids :-)
lol im not supprised, i didnt see his original video's but its great he is uploading them again, and the two transformers one will come :-) A very entertaining man :-)
9:52 That bulb is alive, I know that now It was trying to communicate about some far off galaxy that was on its way here......if here means earth I don't know But it had its little mind fried before it could finish it's transmission. I also now know that PV is anti-alien intelligence and has chosen electricity as his weapon of choice to destroy any manner of alien thought making it to earth. He has voted himself the savior of earth by destroying aliens trying to enhance intelligence any higher.
Presumably if you connect the mains from the zero point right to the far point of the coil rather than that 'nearly at the end' point, the adjustment will be from 0-240? I guess that's for use on devices that will complain loudly if exposed to anything more than 240?
Not much in most cases. However, it is possible to have a situation where the Neutral will be "hot", where it is floating above ground potential. Best not to try touching it. Or you could connect your volt meter between Earth and Neutral to see what it reads.
YES!!! One of my favourite bits at 7:45 "....Ah, that was gooood! I got an arc in that, I gotta do some more." Total LMAO, and ROFL!! QUESTION: What would happen to the variac if it wasn't ballasted, while configured on the 0-460v setting? Would it just burn up, due to not enough windings producing enough flux in order to cause a current-choking effect in the core, thus self-restricting it's own current? I'm interested to know more on this. Thanks for re-loading these clips.
If you were to take the output from the input pins (C & A) and use the variable tap for input (C & E) then with the variac at full scale it would start at mains voltage, turning the dial down should increase the voltage. If the ballast held out, the voltage didn't just arc across the exposed coils and you were isolated enough to operate the dial maybe you could get over 6kv out of it (I figure 27:1 ratio). What do you think?
What do you recommend for ballasting a variac like you have in this video? Is is like a Mercury Vapor ballast or such? How do you connect it to take advantage of the current limiting potential? Just put it in series with the variac leaving the secondary of the ballast open?
Andy did you make them transformers out of old x-ray units?? Well mate I managed to get hold of 3 dentists x- ray heads, and a full setup x-ray unit!! So mate that's 4 all together. That's going to be fun mate!! Should be able to make a nice unit like yours! Just need to get hold of some standoffs Luke yours. That's what I'm struggling to find! Thanx
Photon does that in another vid. He takes 2x toroidal transformers, which are normally 240v in, 110v out, wires them 'backwards', & stuffs 240v into the 110v windings (which are IN SERIES with each other) The 240v windings are then IN SERIES with each other to boost the output upto 464 volts, when a variac is turned upto the max of 270v. In this vid, this the other way of doing it, should you not have a couple of huge toroidals sitting about, & the variac can do such voltages. -BBD.
Interesting,that the variac has no saturation at double the rated voltage.Ordinary transformers usually saturate at about 20% more than operating voltage.
Ok the variac is much simpler than I imagined. But what's a isolation TX do? Magnetically it'll transfer a current surge just like it was a wire. I mean i think of optoisolators. I see how they isolate
Dear photonvids, I tried your overdrive advice but immediately when i plug the variac (without load!) in the mains it started smoking. Fortunately i got it out before it was too damaged. why did this happen? Regards
Talha Khalid the physics of transformer coils and the number of turns you are tapping off compared to the number of coil turns the input is wired to. The voltage goes up and down depending on how many turns are being swept in the brush circuit.
two questions. 1. ballast is just a load in series with the variac, right? 2. if you wired it with a as neutral and b as live would you get more over voltage?
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Put a variac on a variac
Naughty
And put a variac on that
You do realise that’s exactly what he did in his “big boy supply”.
Kaboom?
Ewe shood put on a few Variacs in sieerveez an' 'nen crank 'em 'oop to 'Leven. Watch 'em pop!
I recently learned that variac brushes are not like motor brushes. They're made of a particular variety of carbon that is very conductive in the vertical direction, but not so conductive in the horizontal. This makes it particularly good at carrying current without shorting adjacent windings. It also makes spare brushes super expensive, because variacs are not quite so widely manufactured now that we have VFDs and similar technologies for controlling power.
"And I got a vacuum cleaner attached to it, so you can hear it"
*Hears vacuum cleaner
10s later:
*Hears jet engine
O_O
aprillomat lol
aprillomat it was only less than mains voltage.... your so dramatic
I ain't avinit!
Where's me hammer?
I popped it!
I wanna blow it up!
-Best lines of Photonicinduction.
besides the one line: "you see, here we have shitty houses, quite shitty, and fuck all for gardens, and bull shit tax"
You forgot:
I want flames!
Let's crank it RIGHT up!
Not enough, not avin' that
Flames I want flamea
"I'm gonna pop the cunt" So Brick Top, love it.
Variac = Variable Naughtytranformer
Why am I not surprised that the windings on the upper varied limit are worn out?
John Rand That's Photonicinduction for you! :D
its why im subbed
I think i recognize this device... Seems to be what vietnamise used to electric SHOCK. RAMBO deep in the jungle... I want one tho...
when you turn a lightbulb into an arc lamp
Those old fashioned bulbs put up a pretty good fight.
You let the Magic Smoke Out! :-)
shout outs to the only channel without annotations on every video
The thing that always amazes me is that series wound motors run at such an over speed don't have their armature windings thrown out due to the speed. Just shows how well theyre made even in these sadly cheap times.
+syhooverman Actually DC (and so-called "universal") motors can self-destruct if run without any load. That's why they usually connect a fan (a fan blade) to it to make sure it never runs without a load.
That's one of the most educative videos I've seen recently. Thank you for posting!
been waitin so long 4 this one to be back thanks mate
it could be argued that you are a menace to the power/electronics industry. I absolutely love it! your videos are great!
April 3rd 2020 according to the news..." World on lockdown because of Coronavirus!" Is it as bad as they say? I don't know. I'm at home like most people & TH-cam suggested I watch this... TH-cams A.I. is on overload because, this video is from 8 yrs ago. but its good to see him again! :-)
I just keep learning so much from your videos.
Btw for ya guys who would like to know the variac maker :P CMV 28E-1 | Carroll & Meynell that is the exact model took me a while to figure out the maker
If you drive the 110v connection on the variac it does sort of work as you can see, however the core will probably run into magnetic saturation, fine for short periods but for a long time might well burn out the windings.
All transformers have a higher magnetic field density when they are off load, this is why you can hear photons variac buzzing when off load, but is quiet when on load when the magenetic density is less.
Microwave transformers are similar, they are designed to be on load all the time supplying the magnetron (except while its warming up) so the manufacts cut on the amount of iron core, if you run them off load they will saturate and eventually burn out.
Thank you for the videos
you should put ground on the last tap and 240 on the second last therefore you have a lot more overwind
It would be a spectacular bit of viewing. There probably would not be enough inductance on that short a section of winding so the variac would probably fail in dramatic style. There also would be a very high voltage on the output for the time it is working. Possibly 1,000v or so. It would probably be arcing before it begins to combust. We need a video of this!
Haha Probably
I have a working Variac too, it needed fixing but it is done and it works fine, comes in handy when you need variable output :)
should load an incandescent with an amalgam ball from a CFL, you'd get a well maintained arc in the thing!!!
Hi Photon!
I tried this with very small variac (2A) and it worked. I had input voltage of about 30V and I got 230V output when the input current was 2A with no load. Of course this wasn't at the middle point but somewhere at 1/10 of winding or even less. Thank you for showing this!
Best regards, Electron
Greetings From Australia Photon! I was wondering, how do old school microwave ovens go when grossly overvolted? You know, the no microprocessor type with a twist around mechanical timer. I reckon you ought to give one of those a thrashing :) Pick one renowned for having a highly reliable magnetron so it will take more abuse
I’m very pleased to see, people soldering crimp terminals; makes them so much more reliable! Nicely done, Andy.
Depends on the use, soldering also makes them more brittle so they will break more readily if exposed to vibration or movement over the longer term, at least according to Google.
It’s always best to crimp and solder the wires. There is absolutely no question about it. It’s makes for a great connection (mechanically and electrically). solder does not tend to be brittle. Good quality lead solder doesn’t anyways.
The solder itself is fine, but (according to a number of accounts, I have not done my own comparison) the solder can have a tendency to wick up the wire away from the crimp joint, and if this happens, the point where the solder stops can be placed under stress and the metal wires can fatigue over time and break away. It's well worth looking in to if you're crimping joints because I never would have considered things like this as possible issues.
The arcing bulbs were absolutely fantastic.
Man, I miss this guy. He awesome a crazy
Wow, that variac carries the scars of many serious overloads!
I LOVE YOUR VIDS :D
Very sick experiments. I love it.
Thanks for the lesson, mate. Never knew how one of those worked. Fun and educational!
Dayum joined 15 years ago, you an OG man🙌
ur vids r awesome
I love TheManLabs variac with the 6 brushes. I wish they still made things like they used to.
remember kids, always touch these big terminal screws with your finger after burning down some light bulbs :P
Thanks for the video chaps
How to turn your vacuum cleaner into a rocket 😂
Thaanks good informative video. I wasn't even sure what variac was.
RIP headphone users. That fucking squeak!
I have a bobbin 440-230v transformer. 230 v is 16 amps. Do you think I can use it for 230-110v conversion?
+Ivar .A Yes, you can. The input to output ratio should be around 1:1,91, which turns 230 volts into 120.
Him "This is the inside of a variac."
Me: "Oh that's neat"
Him: "that's where the 240 mains comes in and there's the windings that we can tap for the output"
*taps windings with ball point pen*
Me: "cool, cool"
Him: "I have it attached to a vacuum cleaner so you can hear it power up"
*Jet engine noises*
Me: 0_o "It was on and powered this whole time connected to 240vac?!?!?!? Dafuuuq?"
Yes, this guy is an idiot.
very cool, I didn't think that CFL would take that much voltage, be very careful around CFL's when they blow the mercury gets out, make sure you have good ventilation.
I like the old Genrad Variacs, they go up to 280V!!
I can still hear your voice even though I have this on mute hahaha
I feel like I'm on a watchlist more after watching this video than I did after reading TOTSE
Internet was better on 2012 :(
Thought I’d clicked on to my favourite prog rock album for a minute.
You sir are a very brave man. I have seen things on your channel I never want to experience in real life. Not only is it such a frightening thing electricity is, it also a primeval urge to study and look at it. And after being electrocuted a couple times, I am very wary of electricity. I even put a transformer in my mouth once as I wanted to see what electricity tasted like. Was a 240 volt stepped down to about 12 volts / 2 - 5 amps for a electric piano. Man my heart hurt like crazy. My respect to you, and thank you for showing us the dangers of electricity, and how to respect it.
wonniewarrior the fact that even 0.5 amps is more than enough to stop a human heart, you are extremely lucky to be alive, especially considering you could actually feel its effect on your heart at the time.
I love when you manage to turn the incandescent bulb into a discharge lamp as the filament opens! I have found that on a lot of R-30 and R-40 type incandescents, they can suffer a weird fault where the filament opens but it continues to sustain through a noisy buzzing arc. Turn the light off and it's done for good, but sometimes it'll stay on for DAYS in that arc state.
Sounds like a jet engine :p
it does lol
sounds good
I had an old transformer with a medium sized variac in there, somehow it got so worn it started shorting out, and it caught fire. Fun.
That's a little compartment, and when opened, there's a spare carbon brush in there which would then be attached to the pick-up arm in replacement to the one already on there.
When I got my variac, I got curious and opened the little compartment to find a replacement brush in there. It's only big enough for one brush, so it's not as if I could store a whole stash of them in there. :-D
-BoomBoxDeluxe.
I should have watched right through before posting (!) - it seems there is more margin built-in than I expected! Hard to imagine why they build in so much 'magnetic reserve' unless they design with low flux to minimise iron losses for continuous operation - and for a toroid, the main exit route for heat from iron losses is out through the copper windings.
Nice
Same multimeter I've got if it's good enough for photon must be good enough for me
A ballast is any current limiting device. easiest ones to get hold of are flouro ballasts (18/36 watt) murcury vapor (100/250/400/1000 watt)
the size you need depends on what you are doing.
To hook up, you run it in series with the active (hot) connection. anything on the other side of the ballast will be limited to the ballast's rating (even short circuits) -- warning tho, everything is reference to earth unless you isolate. RCD's (safety switched) are a must as well as the one hand rule.
We popped it!
Interesting vid - can I suggest that over-volting only works if it is within the magnetic design limits of the variac. Like any metal cored transformer, above a certain level of 'volts per turn' the core will saturate and the inductance collapses, causing runaway current and overheating. A ballast just drops the voltage down so you still won't get much higher than the voltages written on the variac! And of course over-current will burn the brushes.
Now thats a super variac :-)
They are dam expensive, a multi tapped auto transformer, nice.
And i thought you were going to put a reversed 440 to 240v transformer on the output.
Great vids :-)
lol im not supprised, i didnt see his original video's but its great he is uploading them again, and the two transformers one will come :-)
A very entertaining man :-)
I wish I could afford a variac...
"i guess i need bigger variac"
Top
No
9:52 That bulb is alive, I know that now
It was trying to communicate about some far off galaxy that was on its way here......if here means earth I don't know
But it had its little mind fried before it could finish it's transmission.
I also now know that PV is anti-alien intelligence and has chosen electricity as his weapon of choice to destroy any manner of alien thought making it to earth.
He has voted himself the savior of earth by destroying aliens trying to enhance intelligence any higher.
Presumably if you connect the mains from the zero point right to the far point of the coil rather than that 'nearly at the end' point, the adjustment will be from 0-240? I guess that's for use on devices that will complain loudly if exposed to anything more than 240?
My brush keeps arcing :(
You should connect a computer to the end of the variac and then see it sizzle out in a plume of thick smoke on the highest voltage!
That would be boring unless the computer has a very shitty power supply without over-current protection.
Cheeky Russian aka Cossack-HD
Straight into the motherboard
Hi photon. We miss your crazy self.
Aye... yer toastin' yer yarbles! Too much it is.
Not much in most cases. However, it is possible to have a situation where the Neutral will be "hot", where it is floating above ground potential. Best not to try touching it. Or you could connect your volt meter between Earth and Neutral to see what it reads.
I wish we had 240v here in the United States! Vacuum cleaners and blenders would be so much better. :)
Hate to break it to you, every service in the US is 240V
YES!!! One of my favourite bits at 7:45
"....Ah, that was gooood! I got an arc in that, I gotta do some more."
Total LMAO, and ROFL!!
QUESTION:
What would happen to the variac if it wasn't ballasted, while configured on the 0-460v setting? Would it just burn up, due to not enough windings producing enough flux in order to cause a current-choking effect in the core, thus self-restricting it's own current?
I'm interested to know more on this.
Thanks for re-loading these clips.
Could you do the over volt on a clear light bulb?
If you were to take the output from the input pins (C & A) and use the variable tap for input (C & E) then with the variac at full scale it would start at mains voltage, turning the dial down should increase the voltage. If the ballast held out, the voltage didn't just arc across the exposed coils and you were isolated enough to operate the dial maybe you could get over 6kv out of it (I figure 27:1 ratio). What do you think?
I just got a plug in step up and down 'no dial', can I put a speed control on it?
Very Naughty!!! :)
This would be interesting to see with unfrosted clear bulbs
What do you recommend for ballasting a variac like you have in this video? Is is like a Mercury Vapor ballast or such? How do you connect it to take advantage of the current limiting potential? Just put it in series with the variac leaving the secondary of the ballast open?
Andy did you make them transformers out of old x-ray units??
Well mate I managed to get hold of 3 dentists x- ray heads, and a full setup x-ray unit!!
So mate that's 4 all together. That's going to be fun mate!!
Should be able to make a nice unit like yours! Just need to get hold of some standoffs Luke yours. That's what I'm struggling to find!
Thanx
What's the advantage of running the center tap with ballast vs. Putting the output of a normal variac to the input of a 1:2 transformer?
thats the ballast, if youre using the variac for 400v, you have to use a ballast.
I wonder how crazy would it get if you put 240 V on that 30 V section (wit a proper ballast): 2 kV output?
Would submerging it in oil solve the problem? Or would it prevent the brushes from making contact?
my varic was 220
i just moved the wire one left (and i can give it one more)
now it can go up to 300V
It seems like jet ebgine in bg
Photon does that in another vid. He takes 2x toroidal transformers, which are normally 240v in, 110v out, wires them 'backwards', & stuffs 240v into the 110v windings (which are IN SERIES with each other) The 240v windings are then IN SERIES with each other to boost the output upto 464 volts, when a variac is turned upto the max of 270v.
In this vid, this the other way of doing it, should you not have a couple of huge toroidals sitting about, & the variac can do such voltages.
-BBD.
lol @ that's a bit naughty. hahahaha
Yes, but amperage is not a limiting factor that cannot be solved with thicker windings, but arcing because of HV is a real concern.
Interesting,that the variac has no saturation at double the rated voltage.Ordinary transformers usually saturate at about 20% more than operating voltage.
Ok the variac is much simpler than I imagined. But what's a isolation TX do? Magnetically it'll transfer a current surge just like it was a wire. I mean i think of optoisolators. I see how they isolate
variacs chained together and all put to 270 volt setting. steps up voltage, right?
Variable ac...vari ac.... variac
PLEASE SEND VIDEO TEXT FOR TRANSLATION. THANK YOU
what do you use as a ballast?
Dear photonvids, I tried your overdrive advice but immediately when i plug the variac (without load!) in the mains it started smoking. Fortunately i got it out before it was too damaged.
why did this happen?
Regards
Did you use a ballast in series with the input to the variac? If not that's why
hows that knob with brush change voltage
Talha Khalid the physics of transformer coils and the number of turns you are tapping off compared to the number of coil turns the input is wired to. The voltage goes up and down depending on how many turns are being swept in the brush circuit.
This guy is Thom Yorke without music! lol
How can I get myself one of those
two questions.
1. ballast is just a load in series with the variac, right?
2. if you wired it with a as neutral and b as live would you get more over voltage?