Just wanted to add that in order for the isolation transformer to work when plugged into itself the outlets that are not in use have to be plugged up, otherwise, electricity might escape. Great video and priceless tip at the end. Thank You!!!
The issue I see with what's been implemented where the secondary ground isn't floating is should you ever connect a device to the transformer that performs its own neutral to ground bond, you're back to having an earth-grounded neutral and back to the possibility of damaging the scope.
If a device performed its own neutral to ground bond it would trip the RCD every time it was plugged in . Which is one reason why devices do not do implement their own neutral to ground bond , being contrary to electrical codes in most countries is another , so it wouldn't be getting a CSA , or UL , or TUV , or whatever the electrical certification standards mark is in your jurisdiction. Lastly under what circumstances would it be a requirement .
There are so many videos on isolation transformers demonstrating the removal of the earth / ground wire of the neutral on the secondary, which I agree with. But why are they sold as isolation transformers because it’s not. If they are connected as originally in this video it’s like a 1:1 auto transformer.
In addition to the existing comments I would add that it may be beneficial to have a 20Amp AC DPDT (H and N) switch selection between the GFCI and a isolated ground duplex receptacle. GFCIs can get flaky below 100VAC when rated at 125VAC, and I use my supply down to very low line voltages when troubleshooting. On my Isolated Variable AC supply output I can select between an isolated ground GFCI and isolated ground non-GFCI duplex receptacle, both are Hospital Grade. I only use the GFCI at nominal or high line as a quick DUT AC leakage check (G tied to N like in a floating power distribution panel). I use an equipment supplemental type 1077 Airpax IEG (upgrade to CEG for UL489A if required) slow trip magnetic hydrauic CB with switch. The Magnetic Hydraulic Airpax (now Sensata) CBs have a many different options for delay trip curves, which is beneficial in selecting one for specific product testing and repair. I also have an accurate AC leakage meter if I have to qualify any equipment for AC leakage after repair. My isolated (20A) variable (15A) AC supply is rated to 15Amps AC overall, but I generally only use it to a max of 10 Amps steady state. The variac has a 20VAC boost for high line testing (135VAC).
Hello, I read that measuring with an oscilloscope, you need an amplifier, you need galvanic separation, I ask from what point of view, when today's amplifiers have only 2 wires. Thank you for any knowledge
First, a transformer or isolation transformer doesn't have a neutral, but has at least 2 hot wires (L1 and L2). To create a neutral on the secondairy side, you must tie L1 or L2 to ground, that one becomes then your neutral. Neutral is almost zero volts, you can't pass zero volts through a transformer from primairy side to secundaire side without a physical connection by wire. But tying L1 or L2 to ground, you are bypassing the whole principle of a "isolation transformer" when you create a neutral on the secundairy side, because by tying L1 or L2 to ground,you are making the secundairy side referenced to ground again, and you will blow up your scope if you connect the ground lead of your scope probe to the remaining hot wire of the secundairy side. Because you did a "demonstration" with your scope probe connected in both ways to your variac without blowing up, it prooves that there isn't any ground connected on your scope or variac. So it seems that you are connected to the mains wall socket using a cheaterplug that has the earthpin disconnected, or your variac itself is isolated, or your wall socket doesn't have a ground connected. To get a real isolation transformer, you must leave the earth/ground from the mains connected to the metal enclosure , but disconnect the groundwire between the metal enclosure and the outlet sockets of the isolation transformer, so that there isn't any continuity between any contact of the outlet sockets and the metal enclosure. This video is very misleading and will cause confusion and damage if people will follow it.
Did you watch the video? Your explanation about how to get a real isolation transformer is what I have done, and I have indicated in the video that the variac is plugged into the isolation transformer. A "cheater plug" would not allow for any type of floating operation in this environment. There are specialized outlets you can buy if you want a separate/isolated earth ground. I chose to maintain the earth ground connection and use a ground fault interrupter in my variac.
@@Datzfunk Yes, i did watch the entire video. But if the variac is behind the isolation transformer, then the output of the variac is floating, and not referenced to ground/earth. A ground fault interrupter can't work without a ground/earth connection. So to get a ground fault interrupter to work, you have to tie one of the 2 hot wires from the output of the variac to ground/earth (and bypass the concept of isolation). Because you did a demonstration with the ground lead of the scope probe connected to each crocodile clamp of the output of the variac, and showed that there was no problem, is proove that you don't have a one of the 2 hot wires connected to ground. To make this story short , isolation (no ground reference) and a working ground fault interrupter doesn't exist. It's or isolation from ground and no ground fault interrupter, or ground referenced (one of the 2 hot wires connected to earth/ground AND chassis of the isolation transformer to create a neutral) and a working ground fault interrupter. Isolation transformer protects devices, while ground fault interrupters protect people. You can't have both at same time.
@@BjornV78 Thanks for the tip about the GFI, I hadn't looked into its mode of operation I can remove it and use it elsewhere. Thinking about it now, it's pointless where it is.
@@Datzfunk i have not mentioned it in my previous message, for not making it more confusable, but there is a simple trick to use a ground fault interrupter / GFI / RCD and have isolation at same time. For a while now i'm building a isolation transformer with buildin very compact "dim bulb current limiter" with small G9 Halogen bulbs. For this project i bought a portable ground fault interrupter of 10mA for using at the output, but came to the conclusion that this can't work without a ground connection. But after some testing, i found a safe solution to have it working and still have enough isolation for preventing to blow up my scope. This simple trick is to bind one of the 2 hot wires from the secundairy of the isolation transformer to the ground pin of the outlet socket, and one of 2 contact pins of the outlet also to this ground pin. If your outlet socket is polarised, you need the neutral side to connect to the ground pin of the outlet socket. Then finally to eliminate a great amount of ghost voltage on this "floating earth", is to connect this "floating earth connection" with 2Mohm (or higher) resistor to the ground of the metal enclosure. The metal enclosure is connected to the earthpin of your wall socket. This 2Mohm (or higher value) needs to be a 1 or 2Watt type (for voltage rating purpose). If you then power up a device from this isolation transformer, and you connect the ground of the scope probe to the hot, then there will only flow arround 120uA (@240V with a 2M resistor) through the earthconnection of your scope.
could you demonstrate with a diagram how isolation transformer affect the oscilloscope connected to mains, and how it affect the oscilloscope and destroy it.
Hi, I was interested in asking you a question about one of these Tripp Lite isolated transformers. I'm a musician. I have several guitar amps in my rec room. The problem is that all of my amps are exhibiting this terrible high end treble fizzy harmonic distortion coming out of the amps. It happens to all of my amps when plugged into my AC outlet plugs. I have this problem throughout my house . It is not isolated just to one room. I have tried disconnecting everything in my house to try and isolate the problem. Perhaps the fridge, computer, flourescent lights, furnace. I even checked the ground connection at my water pipe in the house to check that ground. I then bought one of the cheaper Furman power conditioner for musical equipment. Did absolutely no good. I have no idea what is causing this. It definitely is with the dirty AC power, I'm sure of that. The $64,000.00 dollar question is, how do I get rid of it. I have even had an electrician to my house that said everything was fine with the power. He really didn't have a clue as to what I was talking about. Any good advice on this would be greatly appreciated. Just wanted to know how many watts with a Tripp Lite isolated transformer, would I need to power a 100 watt amp. My other amps are 50 and 30 watt amps. Would one of these transformers do the trick. Would I have to do anything with the ground on one of these. Would one of these totally filter out this dirty power? I have one last question for you. I need to buy a variac to run one of my vintage amps at 110 volts. There are so many different types of variacs to buy. I haven't got a clue as to what American brand to buy. I was looking on eBay at a Superior Electric 3PN116B variac rated at 10A . Any advice on which one to buy . My Fender amp is 40 watts Thanks Michael Newell from Niagara Falls, Ontario, Canada mnewell333@msn.com
That's too bad about the noise from your amps! To confirm that the problem has to do with the power at your location, have you tried moving the amps to another location to see if the problem persists? Unfortunately, I'm not any kind of authority on AC line noise problems. But as Bruce Nitroxpro noted in another comment, the type of isolation transformer I'm using here would probably only reduce noise by accident. He does however mention a: Tripp-Lite isotel "diagnostic surge surpressor" as a possible way to reduce noise. As for the power rating of the amp the Tripp-Lite website does list the power capabilities of their transformers. They have many different models, ones that could easily power your amps. As for the variac, perhaps you don't need one, just a step down transformer; I'm assuming one that would step down 240v to 120v. The variac I'm using in the video is a 7A one if I recall correctly.
Necro-response: If you are trying to determine the current draw from a particular piece of equipment I suggest you get a kill-a-watt or equivalent like the Poniie PN2000 kilowatt meter. This will tell you either the wattage and VA draw from the wall so you can estimate how much suppression or what "size" isolation transformer you may need. I'm doing this to solve a similar problem at my house.
@@kodjostreams7783 Since I last posted this noise problem I bought a $500.00 Hammond isolation medical grade transformer but it has done nothing to get rid of my dirty power sound. Certain times of the day it seems as this goes away but then at some point it returns. I am mesmerized as to why this isolation medical grade transformer does absolutely nothing to get rid of this. I wish I could find a good electricians where I live but when I mentioned dirty power, they had no clue as to what I was even talking about. Brain dead.
@@michel333100 Sounds like emf feedback since you've isolated the power. If you know anybody in the HAM radio hobby I'd wager one of them knows how to use a O-Scope and could tell you for sure about your power condition.
Did you plug your scope into your now isolated from ground variac. I have many forums that discuss not isolating your scope from earth ground but rather plug DUT to isolated from earth ground transformer and not using more than one channel on scope or if you do use more than one channel, use same reference ground with clip on DUT. By the way, thankyou for this wonderful video. I gave you credit for helping me figure out how to remove secondary earth ground on my isolation transformer.
Yep, the variac is isolated, and not the scope. The outer sheath of the scope probes are continuous for most scopes, so any difference in potential between the channels would be a short. Glad to hear you're all set up!
These are usually marketed as "power conditioners", and they do provide isolation from line voltage. But, the neutral being referenced to earth ground means that there will be a potential from earth ground to "hot". For most commercial applications, this type of isolation is all they are looking for.
Free power as long as your input and output are in phase ;) Get this backwards and your device might implode into a black hole on your bench and take your scope with it......
let me ask a question if you need to diagnose an equipment , and if the equipment and oscilloscope both connected to isolation transformer there will be a current flow and will destroy oscilloscope?
Your outlets on the back of the Trip Lite are still tied to earth ground as they are normal receptacles and are picking up ground via the mounting screws. This ground path needs to be removed to truly make it an isolation transformer. I replaced my duplex receptacles with true isolated ground style (orange color) and left the ground not connected. True Isolation.
Thanks for the tip! I was aware of the earth ground still present. I suppose if the device under test has the chassis and neutral connected internally, I'd loose the isolation. The isolated plug type sounds like a good solution.
@@Datzfunk Yes, that was my thought. I think I will add a switch to my Trip-Lite and have the isolated ground outlets able to switch the ground in and out.
@@donaldchapman8392 I think a switch is in general a good idea. In my setup though, I have the isolation transformer plugged into my variac, where there is a ground fault circuit interrupter (GFCI) outlet. If enough current flows to the ground it should break the circuit, thereby adding a safety measure.
If you read enough about isolation transformers, you will find arguments that it's safer to have the output ground terminal floating (so it can't provide a ground return for some other voltage source), and other arguments that it is safer to have the output ground terminal grounded (so an internal insulation failure in the device can't make its case hot with respect to ground). The BBC has written a document (EGN-4, which can be found on the web) that takes a third approach. The BBC points out that if a piece of equipment is wired with neutral and ground interchanged, it will work when plugged into a normal wall outlet, but plugging it into a floating-secondary isolating transformer can actually make the equipment case hot with respect to earth. So, the BBC specifies that the output ground terminal should be left unconnected BUT that any exposed metal on the device should be connected to a ground screw using an external clip lead. That's safer than either of the other two approaches, but requires you to always add another separate grounding wire.
If you have a device somewhere injecting noise on to your mains power that your audio equipment is picking up, an isolation transformer may help. The device I bought does some noise filtering. Keep in mind your audio equipment already is probably isolated with a transformer. I'm not sure if the mod I did would help. I suppose it depends on whether there is also noise on your earth ground wire as well, in which case it might help. Good luck!
@@Datzfunk , It might reduce noise by accident, but not by design. See a Tripp-Lite isotel "diagnostic surge surpressor" which will act to reduce line noise and will definitely protect the audio load. I hope you have a "home over voltage suppression device" on your electrical panel.
I use a power conditioner for that. I purchased one for cheep at Musicians Friend. I know that audiophiles frown on using pro audio gear in their system but that is fluff.
if your audio equipment is picking up noise than its more than likely a ground loop which is likely caused by an electrical connection between a source like a PC and a DAC when using digital coax. I solved mine by using toslink between my PC and DAC which made it dead silent.
The Tripp Lite Line Conditioner LC1200 (1200watts) used price is much lower than the Tripp Lite Isolator IS1000 (1000 watts). I’m trying to find out if I can convert the LC1200 unit to an isolation transformer by eliminating all of the line conditioning features and use the transformer as an isolation transformer. I can’t find schematics to find out if the transformer is an induction transformer or an autotransformer. Has anyone looked into this?
I had a Tripp Lite line conditioner for awhile, from memory it was a step up transformer with relay selectable taps on the secondary, more than anything I think they're created to mitigate the effects of brownouts. It doesn't seem like a good candidate for conversion to a an isolation transformer as it's not going to be a 1:1 ratio.
'''''sir''''''if any of those that measure continuity to ground'''''like neutral to ground continuity.'''''then your in ''danger''' its still not isolated'''''''''remove all ground bonds'''''''''dont want the case grounded'''''''if case has ground bond it''''then it will in return be conected to the ;;ground receptacle''''''dont leave the case grounded''''''''''''then your isolated'''''''''''''' 'no continuity to any receptacle points from ground ''''''''''''''you got it '''''''''''''''''''''''''''''''''''''''''''''''''james;; oklahoma. 73's.......you know old 2 wire 120 is naturally isolated...no ground.....see ya'''''
I see that you have misidentified the right-hand vertical slot (the shorter one) of the duplex outlet as the "neutral" side when, in fact, that right-hand slot (the shorter slot) is actually the hot side of the duplex outlet. In fact, it's the the left-hand, longer, vertical slot that is actually the neutral that, as wired at the factory, comes connected to the ground side of the circuit. Such mistakes can be fatal and you should redo the video.
Interesting. I guess that there is continuity between hot and "neutral" via the secondary winding of the transformer but, given that, there will only be continuity between hot and ground if there is continuity between neutral and ground. So it appears that you can measure it either way.
Also, here's a link to Hammond Manufacturing's specification page to the 171 line of isolation transformers. Take a look at the pdf file link that provides a circuit diagram of the their isolation transformers. Note that both the transformer's primary and secondary sides are independent from one another, yet there is a common ground which is a problem. This because the power mains' neutral is connected to the ground back at the electrical entry panel & that causes a lack of isolation. Also, at d.c. (direct current) the windings on each side of the transformer do act as a short circuit, but that doesn't matter with alternating current because at 50 or 60 Hertz they work just fine. A.C. circuit theory is worth learning about if one is to work on electronics.
@@robertkard3195 Not sure if this was in reply to my post but, if so, it is irrelevant to my point. My point being that, contrary to your assertion that it is dangerous to test the outlets as done in the video it is, indeed, correct as all you are testing for is continuity between ground and neutral and this can be done from either the "hot" side of the outlet or the "neutral" side. This has NOTHING to do with AC theory.
You little joke at the end was just like the think of a lot of people now days I will give the answer why this doesn't work Some people have knowledge in other areas and no nothing about electric this is public schools falt not there own I bet alot of people will appreciate me explaining this Any measurable or usable energy wether it be electric or any other form of energy has to have two differant levels to be useable There has to be a difference of potential to be used Although there is lots usable free energy you can take advantage like two different levels of water You live in endless energy but just like a bird sitting on a power line there is no difference of potential so you don't even realize the incredible amount of energy all around us All energy want to reach equilibrium we take advantage of this natural occurring phenomenon When you push someone on a swing thay come back to you this is what I am talking about and is how the Transformer in the joke works also When the Transformer or swing is pushed one way to pushes back the other always wanting to reach equilibrium There is no pushing of the Transformer when plugged into itself Ac is alternating that means it flips +and- 60 times a second here in usa This mean the +is flipped, to - and at the same time -is flipped to + This is just like you pushing someone on a swing you push forward it comes back you push forward again direction is changing Same with ac electric Some one swinging has a difference in potential that could be used to run something A lot like how a grandfather's clock has a swinging pendulum that sets the time and powers the clock at a constant rate This is the simplest way I know how to explain it
I wish you would have just scratched this video and started over. Throughout it you showed doing one thing, with accompanying narrative, but repeatedly put up tiny text that apparently explains why you are not doing what you say you are, or explaining that what you did was wrong. I came away uncertain about what you did, how you tested it, and what your goal was. Disappointing.
First, thanks for the constructive criticism. The text explains why what I was doing was still valid, despite probing a different portions than I mentioned. I did not go into depth in explaining concepts, as the video was meant for an audience that is somewhat already familiar with them, and is more intended for those with similar transformers who are looking for a quick video in what is involved in its modification. An explanation of the concepts would have been helpful for a larger audience. I'll keep that in mind in making future videos. There are many great videos that explain isolation concepts in regard to these transformers. UA-camr "mjlorton" does a good job if you're interested.
When you went from putting the cover back on then to your auto transformer you lost your audience. There is gap there. How is that done? Just show testing of the outlets on the transformer
you know''''''''' you made the same ;;mistake'' that everybody makes on there first ''modification'' into a isolation transformer''''''''james'' oklahoma...... doest mean ''anything'''''''keep on ''truckin''''''''''see ya.
Just wanted to add that in order for the isolation transformer to work when plugged into itself the outlets that are not in use have to be plugged up, otherwise, electricity might escape. Great video and priceless tip at the end. Thank You!!!
Your joke addendum is not betrayed by any change, or even a giggle. Amazing!
The issue I see with what's been implemented where the secondary ground isn't floating is should you ever connect a device to the transformer that performs its own neutral to ground bond, you're back to having an earth-grounded neutral and back to the possibility of damaging the scope.
If a device performed its own neutral to ground bond it would trip the RCD every time it was plugged in .
Which is one reason why devices do not do implement their own neutral to ground bond , being contrary to electrical codes in most countries is another , so it wouldn't be getting a CSA , or UL , or TUV , or whatever the electrical certification standards mark is in your jurisdiction.
Lastly under what circumstances would it be a requirement .
There are so many videos on isolation transformers demonstrating the removal of the earth / ground wire of the neutral on the secondary, which I agree with. But why are they sold as isolation transformers because it’s not. If they are connected as originally in this video it’s like a 1:1 auto transformer.
In addition to the existing comments I would add that it may be beneficial to have a 20Amp AC DPDT (H and N) switch selection between the GFCI and a isolated ground duplex receptacle. GFCIs can get flaky below 100VAC when rated at 125VAC, and I use my supply down to very low line voltages when troubleshooting. On my Isolated Variable AC supply output I can select between an isolated ground GFCI and isolated ground non-GFCI duplex receptacle, both are Hospital Grade. I only use the GFCI at nominal or high line as a quick DUT AC leakage check (G tied to N like in a floating power distribution panel). I use an equipment supplemental type 1077 Airpax IEG (upgrade to CEG for UL489A if required) slow trip magnetic hydrauic CB with switch. The Magnetic Hydraulic Airpax (now Sensata) CBs have a many different options for delay trip curves, which is beneficial in selecting one for specific product testing and repair.
I also have an accurate AC leakage meter if I have to qualify any equipment for AC leakage after repair. My isolated (20A) variable (15A) AC supply is rated to 15Amps AC overall, but I generally only use it to a max of 10 Amps steady state. The variac has a 20VAC boost for high line testing (135VAC).
Hello, I read that measuring with an oscilloscope, you need an amplifier, you need galvanic separation, I ask from what point of view, when today's amplifiers have only 2 wires. Thank you for any knowledge
First, a transformer or isolation transformer doesn't have a neutral, but has at least 2 hot wires (L1 and L2).
To create a neutral on the secondairy side, you must tie L1 or L2 to ground, that one becomes then your neutral.
Neutral is almost zero volts, you can't pass zero volts through a transformer from primairy side to secundaire side without a physical connection by wire.
But tying L1 or L2 to ground, you are bypassing the whole principle of a "isolation transformer" when you create a neutral on the secundairy side, because by tying L1 or L2 to ground,you are making the secundairy side referenced to ground again, and you will blow up your scope if you connect the ground lead of your scope probe to the remaining hot wire of the secundairy side.
Because you did a "demonstration" with your scope probe connected in both ways to your variac without blowing up, it prooves that there isn't any ground connected on your scope or variac. So it seems that you are connected to the mains wall socket using a cheaterplug that has the earthpin disconnected,
or your variac itself is isolated, or your wall socket doesn't have a ground connected.
To get a real isolation transformer, you must leave the earth/ground from the mains connected to the metal enclosure , but disconnect the groundwire between the metal enclosure and the outlet sockets of the isolation transformer, so that there isn't any continuity between any contact of the outlet sockets and the metal enclosure.
This video is very misleading and will cause confusion and damage if people will follow it.
Did you watch the video? Your explanation about how to get a real isolation transformer is what I have done, and I have indicated in the video that the variac is plugged into the isolation transformer. A "cheater plug" would not allow for any type of floating operation in this environment. There are specialized outlets you can buy if you want a separate/isolated earth ground. I chose to maintain the earth ground connection and use a ground fault interrupter in my variac.
@@Datzfunk Yes, i did watch the entire video.
But if the variac is behind the isolation transformer, then the output of the variac is floating, and not referenced to ground/earth. A ground fault interrupter can't work without a ground/earth connection. So to get a ground fault interrupter to work, you have to tie one of the 2 hot wires from the output of the variac to ground/earth (and bypass the concept of isolation). Because you did a demonstration with the ground lead of the scope probe connected to each crocodile clamp of the output of the variac, and showed that there was no problem, is proove that you don't have a one of the 2 hot wires connected to ground.
To make this story short , isolation (no ground reference) and a working ground fault interrupter doesn't exist. It's or isolation from ground and no ground fault interrupter, or ground referenced (one of the 2 hot wires connected to earth/ground AND chassis of the isolation transformer to create a neutral) and a working ground fault interrupter. Isolation transformer protects devices, while ground fault interrupters protect people. You can't have both at same time.
@@BjornV78 Thanks for the tip about the GFI, I hadn't looked into its mode of operation I can remove it and use it elsewhere. Thinking about it now, it's pointless where it is.
@@Datzfunk i have not mentioned it in my previous message, for not making it more confusable, but there is a simple trick to use a ground fault interrupter / GFI / RCD and have isolation at same time. For a while now i'm building a isolation transformer with buildin very compact "dim bulb current limiter" with small G9 Halogen bulbs. For this project i bought a portable ground fault interrupter of 10mA for using at the output, but came to the conclusion that this can't work without a ground connection. But after some testing, i found a safe solution to have it working and still have enough isolation for preventing to blow up my scope.
This simple trick is to bind one of the 2 hot wires from the secundairy of the isolation transformer to the ground pin of the outlet socket, and one of 2 contact pins of the outlet also to this ground pin. If your outlet socket is polarised, you need the neutral side to connect to the ground pin of the outlet socket. Then finally to eliminate a great amount of ghost voltage on this "floating earth", is to connect this "floating earth connection" with 2Mohm (or higher) resistor to the ground of the metal enclosure. The metal enclosure is connected to the earthpin of your wall socket. This 2Mohm (or higher value) needs to be a 1 or 2Watt type (for voltage rating purpose). If you then power up a device from this isolation transformer, and you connect the ground of the scope probe to the hot, then there will only flow arround 120uA (@240V with a 2M resistor) through the earthconnection of your scope.
@@BjornV78 Interesting, I will have to look into this as an option to keep the GFCI outlet in place. Thanks!
could you demonstrate with a diagram how isolation transformer affect the oscilloscope connected to mains, and how it affect the oscilloscope and destroy it.
Hi, I was interested in asking you a question about one of these Tripp Lite isolated transformers. I'm a musician. I have several guitar amps in my rec room. The problem is that all of my amps are exhibiting this terrible high end treble fizzy harmonic distortion coming out of the amps. It happens to all of my amps when plugged into my AC outlet plugs. I have this problem throughout my house . It is not isolated just to one room. I have tried disconnecting everything in my house to try and isolate the problem. Perhaps the fridge, computer, flourescent lights, furnace. I even checked the ground connection at my water pipe in the house to check that ground. I then bought one of the cheaper Furman power conditioner for musical equipment. Did absolutely no good. I have no idea what is causing this. It definitely is with the dirty AC power, I'm sure of that. The $64,000.00 dollar question is, how do I get rid of it. I have even had an electrician to my house that said everything was fine with the power. He really didn't have a clue as to what I was talking about. Any good advice on this would be greatly appreciated. Just wanted to know how many watts with a Tripp Lite isolated transformer, would I need to power a 100 watt amp. My other amps are 50 and 30 watt amps. Would one of these transformers do the trick. Would I have to do anything with the ground on one of these. Would one of these totally filter out this dirty power? I have one last question for you. I need to buy a variac to run one of my vintage amps at 110 volts. There are so many different types of variacs to buy. I haven't got a clue as to what American brand to buy. I was looking on eBay at a Superior Electric 3PN116B variac rated at 10A . Any advice on which one to buy . My Fender amp is 40 watts Thanks Michael Newell from Niagara Falls, Ontario, Canada mnewell333@msn.com
That's too bad about the noise from your amps! To confirm that the problem has to do with the power at your location, have you tried moving the amps to another location to see if the problem persists? Unfortunately, I'm not any kind of authority on AC line noise problems. But as Bruce Nitroxpro noted in another comment, the type of isolation transformer I'm using here would probably only reduce noise by accident. He does however mention a: Tripp-Lite isotel "diagnostic surge surpressor" as a possible way to reduce noise. As for the power rating of the amp the Tripp-Lite website does list the power capabilities of their transformers. They have many different models, ones that could easily power your amps. As for the variac, perhaps you don't need one, just a step down transformer; I'm assuming one that would step down 240v to 120v. The variac I'm using in the video is a 7A one if I recall correctly.
Necro-response: If you are trying to determine the current draw from a particular piece of equipment I suggest you get a kill-a-watt or equivalent like the Poniie PN2000 kilowatt meter. This will tell you either the wattage and VA draw from the wall so you can estimate how much suppression or what "size" isolation transformer you may need. I'm doing this to solve a similar problem at my house.
are you near a radio tower
@@kodjostreams7783 Since I last posted this noise problem I bought a $500.00 Hammond isolation medical grade transformer but it has done nothing to get rid of my dirty power sound. Certain times of the day it seems as this goes away but then at some point it returns. I am mesmerized as to why this isolation medical grade transformer does absolutely nothing to get rid of this. I wish I could find a good electricians where I live but when I mentioned dirty power, they had no clue as to what I was even talking about. Brain dead.
@@michel333100 Sounds like emf feedback since you've isolated the power. If you know anybody in the HAM radio hobby I'd wager one of them knows how to use a O-Scope and could tell you for sure about your power condition.
Did you plug your scope into your now isolated from ground variac. I have many forums that discuss not isolating your scope from earth ground but rather plug DUT to isolated from earth ground transformer and not using more than one channel on scope or if you do use more than one channel, use same reference ground with clip on DUT. By the way, thankyou for this wonderful video. I gave you credit for helping me figure out how to remove secondary earth ground on my isolation transformer.
Yep, the variac is isolated, and not the scope. The outer sheath of the scope probes are continuous for most scopes, so any difference in potential between the channels would be a short. Glad to hear you're all set up!
Haha great video and funny too!
If you need to modify it to make a true isolation transformer, then how can they market this thing? I’m curious, as a layman...
These are usually marketed as "power conditioners", and they do provide isolation from line voltage. But, the neutral being referenced to earth ground means that there will be a potential from earth ground to "hot". For most commercial applications, this type of isolation is all they are looking for.
Free power as long as your input and output are in phase ;)
Get this backwards and your device might implode into a black hole on your bench and take your scope with it......
Would this work with a Tripp lite IS500 ?? I ordered on waiting on delivery. Will be using for Audio Amp & power supply testing and repair.
i have an LS600 and it doesn't have this issue.
let me ask a question if you need to diagnose an equipment , and if the equipment and oscilloscope both connected to isolation transformer there will be a current flow and will destroy oscilloscope?
You want to have your device under test, and the test equipment on different circuits isolated from one another.
Your outlets on the back of the Trip Lite are still tied to earth ground as they are normal receptacles and are picking up ground via the mounting screws. This ground path needs to be removed to truly make it an isolation transformer. I replaced my duplex receptacles with true isolated ground style (orange color) and left the ground not connected. True Isolation.
Thanks for the tip! I was aware of the earth ground still present. I suppose if the device under test has the chassis and neutral connected internally, I'd loose the isolation. The isolated plug type sounds like a good solution.
@@Datzfunk Yes, that was my thought. I think I will add a switch to my Trip-Lite and have the isolated ground outlets able to switch the ground in and out.
@@donaldchapman8392 I think a switch is in general a good idea. In my setup though, I have the isolation transformer plugged into my variac, where there is a ground fault circuit interrupter (GFCI) outlet. If enough current flows to the ground it should break the circuit, thereby adding a safety measure.
If you read enough about isolation transformers, you will find arguments that it's safer to have the output ground terminal floating (so it can't provide a ground return for some other voltage source), and other arguments that it is safer to have the output ground terminal grounded (so an internal insulation failure in the device can't make its case hot with respect to ground).
The BBC has written a document (EGN-4, which can be found on the web) that takes a third approach. The BBC points out that if a piece of equipment is wired with neutral and ground interchanged, it will work when plugged into a normal wall outlet, but plugging it into a floating-secondary isolating transformer can actually make the equipment case hot with respect to earth. So, the BBC specifies that the output ground terminal should be left unconnected BUT that any exposed metal on the device should be connected to a ground screw using an external clip lead. That's safer than either of the other two approaches, but requires you to always add another separate grounding wire.
Simply use a 2 prong plug (or cheater plug) on the outlet of the isolation transformer and problem solved.
Doesn't the variac already provide isolation?
Unfortunately, a Variac does not provide any electrical isolation.
And that is because it is an AUTO-TRANSFORMER. Like the coil in your car. It is a single coil with taps or a wiper. No Isolation in that setup.
can you take this further, and put a dim bulb setup in it ?
Yep, I have a dim bulb setup for this too.
Will this reduce electrical outlet noise for high-end audio equipment?
If you have a device somewhere injecting noise on to your mains power that your audio equipment is picking up, an isolation transformer may help. The device I bought does some noise filtering. Keep in mind your audio equipment already is probably isolated with a transformer. I'm not sure if the mod I did would help. I suppose it depends on whether there is also noise on your earth ground wire as well, in which case it might help. Good luck!
@@Datzfunk , It might reduce noise by accident, but not by design. See a Tripp-Lite isotel "diagnostic surge surpressor" which will act to reduce line noise and will definitely protect the audio load. I hope you have a "home over voltage suppression device" on your electrical panel.
I use a power conditioner for that. I purchased one for cheep at Musicians Friend. I know that audiophiles frown on using pro audio gear in their system but that is fluff.
if your audio equipment is picking up noise than its more than likely a ground loop which is likely caused by an electrical connection between a source like a PC and a DAC when using digital coax. I solved mine by using toslink between my PC and DAC which made it dead silent.
The Tripp Lite Line Conditioner LC1200 (1200watts) used price is much lower than the Tripp Lite Isolator IS1000 (1000 watts).
I’m trying to find out if I can convert the LC1200 unit to an isolation transformer by eliminating all of the line conditioning features and use the transformer as an isolation transformer. I can’t find schematics to find out if the transformer is an induction transformer or an autotransformer. Has anyone looked into this?
I had a Tripp Lite line conditioner for awhile, from memory it was a step up transformer with relay selectable taps on the secondary, more than anything I think they're created to mitigate the effects of brownouts. It doesn't seem like a good candidate for conversion to a an isolation transformer as it's not going to be a 1:1 ratio.
'''''sir''''''if any of those that measure continuity to ground'''''like neutral to ground continuity.'''''then your in ''danger''' its still not isolated'''''''''remove all ground bonds'''''''''dont want the case grounded'''''''if case has ground bond it''''then it will in return be conected to the ;;ground receptacle''''''dont leave the case grounded''''''''''''then your isolated'''''''''''''' 'no continuity to any receptacle points from ground ''''''''''''''you got it '''''''''''''''''''''''''''''''''''''''''''''''''james;; oklahoma. 73's.......you know old 2 wire 120 is naturally isolated...no ground.....see ya'''''
You should have your scope plugged in with no Isolation . THE equipment under test should be isolated .
Yep, that's what's going on.
They should not be able to sell it as an isolation transformer since it is not.
I see that you have misidentified the right-hand vertical slot (the shorter one) of the duplex outlet as the "neutral" side when, in fact, that right-hand slot (the shorter slot) is actually the hot side of the duplex outlet. In fact, it's the the left-hand, longer, vertical slot that is actually the neutral that, as wired at the factory, comes connected to the ground side of the circuit. Such mistakes can be fatal and you should redo the video.
Interesting. I guess that there is continuity between hot and "neutral" via the secondary winding of the transformer but, given that, there will only be continuity between hot and ground if there is continuity between neutral and ground. So it appears that you can measure it either way.
@@Jnglfvr
This UA-cam video from Mr. Carlson's Lab is quite good at explaining the issue.
ua-cam.com/video/XBsQ3sZ45Fk/v-deo.html
Also, here's a link to Hammond Manufacturing's specification page to the 171 line of isolation transformers. Take a look at the pdf file link that provides a circuit diagram of the their isolation transformers. Note that both the transformer's primary and secondary sides are independent from one another, yet there is a common ground which is a problem. This because the power mains' neutral is connected to the ground back at the electrical entry panel & that causes a lack of isolation. Also, at d.c. (direct current) the windings on each side of the transformer do act as a short circuit, but that doesn't matter with alternating current because at 50 or 60 Hertz they work just fine. A.C. circuit theory is worth learning about if one is to work on electronics.
@@robertkard3195 Not sure if this was in reply to my post but, if so, it is irrelevant to my point. My point being that, contrary to your assertion that it is dangerous to test the outlets as done in the video it is, indeed, correct as all you are testing for is continuity between ground and neutral and this can be done from either the "hot" side of the outlet or the "neutral" side. This has NOTHING to do with AC theory.
You little joke at the end was just like the think of a lot of people now days
I will give the answer why this doesn't work
Some people have knowledge in other areas and no nothing about electric this is public schools falt not there own
I bet alot of people will appreciate me explaining this
Any measurable or usable energy wether it be electric or any other form of energy
has to have two differant levels to be useable
There has to be a difference of potential to be used
Although there is lots usable free energy you can take advantage like two different levels of water
You live in endless energy but just like a bird sitting on a power line there is no difference of potential so you don't even realize the incredible amount of energy all around us
All energy want to reach equilibrium
we take advantage of this natural occurring phenomenon
When you push someone on a swing thay come back to you this is what I am talking about and is how the Transformer in the joke works also
When the Transformer or swing is pushed one way to pushes back the other always wanting to reach equilibrium
There is no pushing of the Transformer when plugged into itself
Ac is alternating that means it flips +and-
60 times a second here in usa
This mean the +is flipped, to - and at the same time -is flipped to +
This is just like you pushing someone on a swing you push forward it comes back you push forward again direction is changing
Same with ac electric
Some one swinging has a difference in potential that could be used to run something
A lot like how a grandfather's clock has a swinging pendulum that sets the time and powers the clock at a constant rate
This is the simplest way I know how to explain it
I wish you would have just scratched this video and started over.
Throughout it you showed doing one thing, with accompanying narrative, but repeatedly put up tiny text that apparently explains why you are not doing what you say you are, or explaining that what you did was wrong.
I came away uncertain about what you did, how you tested it, and what your goal was.
Disappointing.
First, thanks for the constructive criticism. The text explains why what I was doing was still valid, despite probing a different portions than I mentioned. I did not go into depth in explaining concepts, as the video was meant for an audience that is somewhat already familiar with them, and is more intended for those with similar transformers who are looking for a quick video in what is involved in its modification. An explanation of the concepts would have been helpful for a larger audience. I'll keep that in mind in making future videos. There are many great videos that explain isolation concepts in regard to these transformers. UA-camr "mjlorton" does a good job if you're interested.
When you went from putting the cover back on then to your auto transformer you lost your audience. There is gap there. How is that done? Just show testing of the outlets on the transformer
you know''''''''' you made the same ;;mistake'' that everybody makes on there first ''modification'' into a isolation transformer''''''''james'' oklahoma...... doest mean ''anything'''''''keep on ''truckin''''''''''see ya.