I recently was given a TDGC-0.5 which was butchered after an attempt to modify it. After almost a year of searching for proper schematics and wiring diagrams, I came across your video. After a few screen shots and 30 minutes later, I now have a working Variac! Thanks for the upload!
I just bought one,2kva with digital meter. Came with a big dent in the side. So I opened it up and the hot snot was everywhere, the cord retainer grommet was loose and covered in snot. The solder was appalling and the dent was bad enough that it hit the coil and broke through the enamel on the coil. The Amazon listing for it said "free returns," so I go to return it and since it was shipped by the seller not Amazon I had to contact them. They say they're gonna take the cost of shipping the return out of my refund. I said oh no, said on the listing free returns. They wanted pics of the damage. So I send pics and they come back with well due to the trouble of returning the unit would I be satisfied with $65 back and just keep the unit. SURE. So I fixed it, re enameled the whole coil for good measure, secured the cord with American hardware and reflowed all the solder joints and now she works fine. Thanks China for a 20$ variable. Bout all its worth when I got it!
I also added another fuse holder inside the panel which covers the output and therefore the device under test. Put a 20 amp slow blow in there for good measure and whenever I want to abuse the thing I stick a 50 amp in each fuse holder. I've practically had her smoking running some of my crazy projects. It's been a few months since I got it and honestly I'm impressed with the overall durability. They really can take a lickin
I've been using one of these variacs to control the speed of a fan in my room for over two years. It started sparking and feeling crunchy when I turned the dial, so I took it apart and cleaned the carbon deposits off the coil. Works good as new!
Thank you, I have one where the plugs failed, so i grabbed a metal box, receptacle and some wiring to just pigtail it to the output, but bypassing everything in the box due to crappy wiring and solders I got confused on what wire goes where and hooked up the wiper to the neutral input instead of output only. i powered it with a switch on the power to it, (smartest thing i did so far lol) It buzzed and smoked a little then i flipped it off. guess i wore that brush down a little. I knew it had to be something stupid on my end. Hard to find relevant info for these. all i needed to know were the basics of what goes where, YEL to Neutral Output only, front side of coil to input/ouput hot side. Side coil RED to neutral input. Here I go to fix it, hope this is right. Thanks again
Update: its working now, no fuze and no switch but its working. I guess of it burns up ill just unplug it quick, it is hooked to a gfci receptacle and what i am running has a built in one on the plug.
I just acquired an interesting product It's a fan speed controller but it's basically a simplified cable transform it literally is just a metal box with a dial and a power input and a power output. The box is riveted together so there's no way to get inside it. Talk about a mystery box I think it's rated at 3 amp. It's amazing when they work because it works perfectly with really fine adjustment of voltage. I did have an old-fashioned berco, rated at 10:00 a.m. and you could feel the quality of that unit but it was actually rather unsafe, huge vent holes giving access to a live coil. I'm greatly impressed. I'm worried about my unit I need to test the earth but there's no other access and I would literally have to drill out about 8 rivets which I don't fancy doing since it's working but anyway. It was extra cheap cost £100
Amazon quality never fails to disappoint. Meanwhile I'm currently using a variac originally purchased and used by my dad in the early 60's and it still works flawlessly over the entire range.
Good catch! I have a smaller one, and the way I use it, I cannot even see the top dial. For the rare times I use it, I just meter it for the proper voltage.
Great video thank you. I just got one of these, the wrong one without LCD and it was smashed in delivery. Refunded. I replaced the broken plug and got it working but after watching your video i wonder if theres a better quality one worth the money that is linear with an LCD. if you have a recommendation, let me know. Thank you.
The quality on most Chinese "variacs" is fairly appalling. Clearly the factory doesn't test the final product prior to shipping. Miss wiring can be deadly. I recommend anyone needing a low cost variable auto transformer consider buying a used Powerstat, Stenco or Variac product. Just make sure the seller has good feedback and the product is covered by a return warranty. Good luck.
The flip side could be that anyone using one should probably have the knowledge enough to debug and remedy any problems with it since it is not a certified household appliance ¯\_(ツ)_/¯
I have something called an Amp RX Brownbox which is a high quality unit specifically made for lowering the voltages on vintage guitar amps that were made to take anywhere from 110-117 volts ...I need a 2nd variac and was looking to spend a lot less...if I come across this issue on a cheap-o Chinese unit,I'm now prepared,thanks!
Also, the fuse... isn't in the best spot. You want a fuse upstream of the load #1 and #2 you want it to protect the supply and yourself! I added a 15 amp slow blow fuse and holder to the yellow wire coming off of the sweep to protect the coil FIRST. The way they have it fused is the power comes in from the wall and through the 20amp fuse first, which is all good and fine but doesn't directly protect the coil or the load! I went with a 15 amp slow blow because everything inside the unit, from the plugs to the Guage of the coil wire is only rated for 15 amps, NOT 20! Other than that it's worked flawlessly all the way up to practically smoking. (Pushed her to get any failures out of the way early) good video man. Keep it up
i have one of these and when i attach it to a full bridge rectifier the variac gets noisy and very hot at 50 volts the variac goes to 100 c temp , i can even smell the varnish is that normal or what do you think the issue is ?
Note: Set scale to % not V- still doesn't align but probably what it should be. More repair videos here! ruclips.net/p/PLxyM2a_cfnzhjL7rjQ8jbDGyy_LvG-5bZ
I am not involved with electronics so you will have to read between the lines if I use the incorrect term. I bought one on these VARIAC units off eBay last night for $59 and free shipping. I can see I will have to follow your lead and thoroughly check it out. The purpose is to power a 24 volt wheel chair motor DC Voltage. I know a little bit about a rectifier bridge coming from a welding background. I have a 1200 volt 200 amp bridge to give me an output of DC voltage. Maybe I'm wrong but I thought by turning the knob on the transformer and measuring the output from the bridge I could find the 24 volts???????? I was told I had to use a capacitor as well. I have no clue. I searched RUclips looking for a simple build converting 120 volt AC house hold current to DC 24 volt to run the motor. I appreciate you doing this video, I can see that items brand new out of the box especially with China stamped on them might be at fault and not work properly. I intend to look at your channel and see what else I can learn. Thank you. I will subscribe
Firstly, a variac is not a power supply. Secondly for someone who admits that they know nothing about electricity to go messing about with a a 1200v 200A welder in order to power a 24 v wheelchair motor borders on Lunacy. Google your local health care centre and ask them to put you in touch with someone who supplies chargers for wheelchairs. Far safer and much cheaper in the long run .
Great video and repair. I have acquired a STACO ENGERY 1010B uncased. I am having the same problem you had with the variac wired the wrong way. It is a 5 pin connection and I am wondering if you could help me getting the voltage to start at from off to130vac.
I think you omit main reason of fuse blowing problem. Every transformer suffers on start of initial "inrush" current on primary coil which can be 10 times higher than normal current. It means that hundred of watts transformer is able to blow up your home socket fuses. These big variacs have 500-3000W and are able to generate 100A peak in first tens of seconds after start. The solution is soft start circuit which is used on powerfull audio amplifiers equipped by toroid tranformers. Simplest form is a resistor in series with primary transformer coil controlled by time relay. The resistor is bridged by relay contact after first second or something like that. Slow blow (motor) fuse is another solution. It is definitely sad that the producer is able to switch input and output plugs as the reversed voltage may be high enough to damage coil insulation and take the transformer down. And it is the better option considering that you can easily reach very dangerous high voltage in the output plug.
@@MkmeOrg I just checked it out, the output is in DC; I need AC. I need the 15VAC to do lead ID testing on 3 phase motors. Tried using DC and didn't work. Any variable power supplies with AC output under $100 you know of?
I have a similar unit that I got off of Amazon a year or two ago. It works fine but at the time they claimed that it was also an isolation transformer. No way that's true. Dangerous!
Just got my 1kv today. Glass is cracked gauge is moved back. But needle looks intact So i better get to work with superglue to repair the cracked glass. If such can be done. It looks that we have the same model so if i have to swap out the display then what do you reccommend I've send a picture and better hear what they say. I wont dare to plug a tube amp into this yet
I had the same issue with a 30 KVA variac. I put a switch on the output. So I have both a step up and step down variac. DO NOT TRY THIS UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING.
I just bought another one and the Ground from the power cord was lose and got up agents the coil and shorted out and burnt the first 1 1/2 inches of the coil.
get a better display for it. i put a nicer digital one in mine and also wired up a panel that have lots of info. then i have a nice accurate display on the front
@@TR3A sure thing. look on aliexpress for part number D91-21 it's identical in size and drops right into the same hole. You just re use the frame around the analog one. this new one snaps into that frame from the existing one then they together snap into the hole. Super easy install.
It is also a Variac! Variable alternating current! The reason it is called a Variac is because it is an auto transformer that is variable! Auto transformers do not have to be variable but Variacs do, GET IT?!
I just bought one a few days ago. Arrived today, plugged it in and it hummed very loudly. Blew its fuse within half a second. I have to say that the variac is a 110V one and I ran it on 230V. But that shouldn't matter right? Do you know what I could have done wrong? Can you help? Seems really similar, but my connections were right.
You have a variac that runs on 110 Volts. You can;t run it on a 230 Volt supply so you must plug it into a step up/down transformer. The unit looks like a little black transformer but has a American socket modified with a European socket design with it. Make sure you get one that has a mains supply line with the European plug on it (assuming your in the UK) although I have seen adapter jacks that allow it to be plugged into 110 Volts so we in the USA can run it as a step up transformer. The THG-1000 should fit the bill but you didn't say what you are powering up with it. The 1000 Watts will do you fine for anything!
Why do you people have to state these are NOT variacs but auto transformers? They are auto transformers but they are variable, hence the name variac as in variable. Do you people still call motor vehicles preambulators? If not why not? So in conclusion, people that boast how clever they are by stating these are NOT variacs are clearly showing how dense they really are! VARIABLE ALTERNATING CURRENT! IT'S A TRANSFORMER WHICH CAN BE VARIATED!
I recently was given a TDGC-0.5 which was butchered after an attempt to modify it. After almost a year of searching for proper schematics and wiring diagrams, I came across your video. After a few screen shots and 30 minutes later, I now have a working Variac! Thanks for the upload!
I just bought one,2kva with digital meter. Came with a big dent in the side. So I opened it up and the hot snot was everywhere, the cord retainer grommet was loose and covered in snot. The solder was appalling and the dent was bad enough that it hit the coil and broke through the enamel on the coil. The Amazon listing for it said "free returns," so I go to return it and since it was shipped by the seller not Amazon I had to contact them. They say they're gonna take the cost of shipping the return out of my refund. I said oh no, said on the listing free returns. They wanted pics of the damage. So I send pics and they come back with well due to the trouble of returning the unit would I be satisfied with $65 back and just keep the unit. SURE. So I fixed it, re enameled the whole coil for good measure, secured the cord with American hardware and reflowed all the solder joints and now she works fine. Thanks China for a 20$ variable. Bout all its worth when I got it!
I also added another fuse holder inside the panel which covers the output and therefore the device under test. Put a 20 amp slow blow in there for good measure and whenever I want to abuse the thing I stick a 50 amp in each fuse holder. I've practically had her smoking running some of my crazy projects. It's been a few months since I got it and honestly I'm impressed with the overall durability. They really can take a lickin
I've been using one of these variacs to control the speed of a fan in my room for over two years. It started sparking and feeling crunchy when I turned the dial, so I took it apart and cleaned the carbon deposits off the coil. Works good as new!
Thank you, I have one where the plugs failed, so i grabbed a metal box, receptacle and some wiring to just pigtail it to the output, but bypassing everything in the box due to crappy wiring and solders I got confused on what wire goes where and hooked up the wiper to the neutral input instead of output only. i powered it with a switch on the power to it, (smartest thing i did so far lol) It buzzed and smoked a little then i flipped it off. guess i wore that brush down a little. I knew it had to be something stupid on my end. Hard to find relevant info for these. all i needed to know were the basics of what goes where, YEL to Neutral Output only, front side of coil to input/ouput hot side. Side coil RED to neutral input. Here I go to fix it, hope this is right. Thanks again
Update: its working now, no fuze and no switch but its working. I guess of it burns up ill just unplug it quick, it is hooked to a gfci receptacle and what i am running has a built in one on the plug.
I just acquired an interesting product It's a fan speed controller but it's basically a simplified cable transform it literally is just a metal box with a dial and a power input and a power output. The box is riveted together so there's no way to get inside it. Talk about a mystery box I think it's rated at 3 amp. It's amazing when they work because it works perfectly with really fine adjustment of voltage. I did have an old-fashioned berco, rated at 10:00 a.m. and you could feel the quality of that unit but it was actually rather unsafe, huge vent holes giving access to a live coil. I'm greatly impressed. I'm worried about my unit I need to test the earth but there's no other access and I would literally have to drill out about 8 rivets which I don't fancy doing since it's working but anyway. It was extra cheap cost £100
Amazon quality never fails to disappoint. Meanwhile I'm currently using a variac originally purchased and used by my dad in the early 60's and it still works flawlessly over the entire range.
Good catch! I have a smaller one, and the way I use it, I cannot even see the top dial. For the rare times I use it, I just meter it for the proper voltage.
Yeah the dial graduations aren't really something I will use either. Cheers Garth
I got lucky with my little 3A variac. I have always wanted one and finally bought one for my retirement hobby bench. Good trouble shooting
I've been eyeing them for years but not something I need very often. A little disappointing that it came this way but easy enough fix :)
This video was crazy helpful. Thanks!
I order the same model and works great ,, order tgis divice on my bench for bring back to life old tube gears with dim bulb tester
Great video thank you. I just got one of these, the wrong one without LCD and it was smashed in delivery. Refunded.
I replaced the broken plug and got it working but after watching your video i wonder if theres a better quality one worth the money that is linear with an LCD. if you have a recommendation, let me know. Thank you.
The quality on most Chinese "variacs" is fairly appalling. Clearly the factory doesn't test the final product prior to shipping. Miss wiring can be deadly. I recommend anyone needing a low cost variable auto transformer consider buying a used Powerstat, Stenco or Variac product. Just make sure the seller has good feedback and the product is covered by a return warranty. Good luck.
The flip side could be that anyone using one should probably have the knowledge enough to debug and remedy any problems with it since it is not a certified household appliance ¯\_(ツ)_/¯
I have something called an Amp RX Brownbox which is a high quality unit specifically made for lowering the voltages on vintage guitar amps that were made to take anywhere from 110-117 volts ...I need a 2nd variac and was looking to spend a lot less...if I come across this issue on a cheap-o Chinese unit,I'm now prepared,thanks!
Welcome! Good luck with your unit
Also, the fuse... isn't in the best spot. You want a fuse upstream of the load #1 and #2 you want it to protect the supply and yourself! I added a 15 amp slow blow fuse and holder to the yellow wire coming off of the sweep to protect the coil FIRST. The way they have it fused is the power comes in from the wall and through the 20amp fuse first, which is all good and fine but doesn't directly protect the coil or the load! I went with a 15 amp slow blow because everything inside the unit, from the plugs to the Guage of the coil wire is only rated for 15 amps, NOT 20! Other than that it's worked flawlessly all the way up to practically smoking. (Pushed her to get any failures out of the way early) good video man. Keep it up
What electrical gloves do you usually wear when working with high voltage ?
i have one of these and when i attach it to a full bridge rectifier the variac gets noisy and very hot at 50 volts the variac goes to 100 c temp , i can even smell the varnish is that normal or what do you think the issue is ?
Note: Set scale to % not V- still doesn't align but probably what it should be. More repair videos here! ruclips.net/p/PLxyM2a_cfnzhjL7rjQ8jbDGyy_LvG-5bZ
I am not involved with electronics so you will have to read between the lines if I use the incorrect term. I bought one on these VARIAC units off eBay last night for $59 and free shipping. I can see I will have to follow your lead and thoroughly check it out. The purpose is to power a 24 volt wheel chair motor DC Voltage. I know a little bit about a rectifier bridge coming from a welding background. I have a 1200 volt 200 amp bridge to give me an output of DC voltage. Maybe I'm wrong but I thought by turning the knob on the transformer and measuring the output from the bridge I could find the 24 volts???????? I was told I had to use a capacitor as well. I have no clue. I searched RUclips looking for a simple build converting 120 volt AC house hold current to DC 24 volt to run the motor. I appreciate you doing this video, I can see that items brand new out of the box especially with China stamped on them might be at fault and not work properly. I intend to look at your channel and see what else I can learn. Thank you. I will subscribe
Firstly, a variac is not a power supply. Secondly for someone who admits that they know nothing about electricity to go messing about with a a 1200v 200A welder in order to power a 24 v wheelchair motor borders on Lunacy. Google your local health care centre and ask them to put you in touch with someone who supplies chargers for wheelchairs. Far safer and much cheaper in the long run .
Great video and repair. I have acquired a STACO ENGERY 1010B uncased. I am having the same problem you had with the variac wired the wrong way. It is a 5 pin connection and I am wondering if you could help me getting the voltage to start at from off to130vac.
I think you omit main reason of fuse blowing problem. Every transformer suffers on start of initial "inrush" current on primary coil which can be 10 times higher than normal current. It means that hundred of watts transformer is able to blow up your home socket fuses. These big variacs have 500-3000W and are able to generate 100A peak in first tens of seconds after start. The solution is soft start circuit which is used on powerfull audio amplifiers equipped by toroid tranformers. Simplest form is a resistor in series with primary transformer coil controlled by time relay. The resistor is bridged by relay contact after first second or something like that. Slow blow (motor) fuse is another solution. It is definitely sad that the producer is able to switch input and output plugs as the reversed voltage may be high enough to damage coil insulation and take the transformer down. And it is the better option considering that you can easily reach very dangerous high voltage in the output plug.
I need something like this to produce 15VAC; what RELIABLE equipment would you recommend? Preferably from Amazon.
You need to specify the amperage needed. Here is a 60W PSU amzn.to/3UFEZKF
@@MkmeOrg I just checked it out, the output is in DC; I need AC. I need the 15VAC to do lead ID testing on 3 phase motors. Tried using DC and didn't work. Any variable power supplies with AC output under $100 you know of?
Imagine someone wanting to mimic Van Halen 90 volt Brown Sound tone and fry their 5K Marshall Plexi !
I have a similar unit that I got off of Amazon a year or two ago. It works fine but at the time they claimed that it was also an isolation transformer. No way that's true. Dangerous!
I'm in the same boat with a 3 amp variac. I'm printing a new front panel so I have digital voltage reading
I've got an old lab supply that has a sing on it (don't adjust while switched on), I wonder if thats because it kept blowing fuses.
Can I connect this to my power station to test its power capabilities? I have a Bluetti ac200max
Thanks I just ordered one. If I have problems I think I know what to do, thanks to you. Friggen Chinese
Just got my 1kv today. Glass is cracked gauge is moved back. But needle looks intact
So i better get to work with superglue to repair the cracked glass. If such can be done. It looks that we have the same model so if i have to swap out the display then what do you reccommend
I've send a picture and better hear what they say.
I wont dare to plug a tube amp into this yet
I had the same issue with a 30 KVA variac. I put a switch on the output. So I have both a step up and step down variac. DO NOT TRY THIS UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING.
Build date: Just before knock-off siren went.
Great vid Mate.
5 o'clock on a Friday special!
@@MkmeOrg Was going to say the same, but those guys work weird hours, like 24/7.
Just discovered your channel. Interesting, Thank You!
I just bought another one and the Ground from the power cord was lose and got up agents the coil and shorted out and burnt the first 1 1/2 inches of the coil.
Amazon buyers are like damn! they see this video oh we can fix? yeah baby yeah... "Austin Powers" 😄
If it does not work after return period, buy another one and return the defective unit.
Or fix it and learn something, save some CO2 emissions and teach others…
After watching this, I wouldn’t trust these without a multi meter.
"Strain relief" is Chinese for hot glue. I have one very similar to that with the same hot snot strain relief. lol.
Dont you just hate when you buy something new and you have to fix it before fixing whatever you bought to fix it with lol
Yup just gotta make the best of it
It is a left handed unit ;)
Did you adjust the amount electricity to the 110 volt
Makes you worry when the include a bag of fuses with a product.
Nice vid. These red autotransformers are truly appalling.
get a better display for it. i put a nicer digital one in mine and also wired up a panel that have lots of info. then i have a nice accurate display on the front
Can you share what dislay you used? I'd like to make the same modification.
@@TR3A sure thing. look on aliexpress for part number D91-21 it's identical in size and drops right into the same hole. You just re use the frame around the analog one. this new one snaps into that frame from the existing one then they together snap into the hole. Super easy install.
@@TR3A you can also find it here with the frame included: www.mpja.com/AC-Digital-Panel-Meter-0-500V-Separate-Power-3Wire/productinfo/32931%20ME/
@@th3drizzl378 Thank-you!
@@TR3A no problem!
Why set it to 110? Your mains is 120
Bravo.....it a auto-transformer........cheers
It is also a Variac! Variable alternating current! The reason it is called a Variac is because it is an auto transformer that is variable! Auto transformers do not have to be variable but Variacs do, GET IT?!
Mine didn’t work either … it had no fuse 😂
I just bought one a few days ago. Arrived today, plugged it in and it hummed very loudly. Blew its fuse within half a second. I have to say that the variac is a 110V one and I ran it on 230V. But that shouldn't matter right? Do you know what I could have done wrong? Can you help? Seems really similar, but my connections were right.
You have a variac that runs on 110 Volts. You can;t run it on a 230 Volt supply so you must plug it into a step up/down transformer.
The unit looks like a little black transformer but has a American socket modified with a European socket design with it. Make sure you get one that has a mains supply
line with the European plug on it (assuming your in the UK) although I have seen adapter jacks that allow it to be plugged into 110 Volts
so we in the USA can run it as a step up transformer. The THG-1000 should fit the bill but you didn't say what you are powering up with it.
The 1000 Watts will do you fine for anything!
@@hestheMaster I know. I already have an autotransformer for stepdown. Now I'm just missing a US power cord.
Why do you people have to state these are NOT variacs but auto transformers? They are auto transformers but they are variable, hence the name variac as in variable. Do you people still call motor vehicles preambulators? If not why not? So in conclusion, people that boast how clever they are by stating these are NOT variacs are clearly showing how dense they really are! VARIABLE ALTERNATING CURRENT! IT'S A TRANSFORMER WHICH CAN BE VARIATED!
Man, those things scare me.
Interesting. So they have zero quality control, not even function control.
gina, buy from europe
Never buy from amazon go to aliexpress
Typical Chinese manufacturing & QC
His breathing and smacking is soooo annoying