Nice video. A few suggestions to help with high percentage bobbing fills. 1) Keep all tape on the front or back side of the bobbin. Even just a few thousandths in the lamination areas add up quickly. 2) Keep winding layers neat, gaps and overlaps will cause uneven layers and eat up space very quickly. 3) Keep overlap for paper layers to around 250 thousandths and make sure all internal paper layer seams are on the front or rear faces. 4) Eliminate the heat shrink tubing and instead partially strip the lead wire leaving the insulation stub on the end of the lead wire. Strip the insulation off of the magnet wire and wrap it around the exposed lead wire conductors. Solder in place. Tape the lead wire to the bobbin and make sure the lead wire stretches across the entire width of the bobbin. Doing this will result in a more stable uniform winding layer. Do the same when you finish the winding and the second lead wire. Use your judgement when determining when to bury lead wires or bring out the windings. If the diameter of the winding wire is less than the thickness of the lead wire insulation, it should be fine to bury the leads.
Thank you for your input! It's difficult to have a definite answer for some of the winding techniques since there are many ways to go about it and many different situations and conditions that will call for something different every time. The most important thing is for the "amateur" winder is to make sure the transformer will be safe, use only two coat enamel wire where the insulation can withstand high voltage and high temperature and the second objective is to fit the wire so that the laminations can be inserted without rubbing on the finished windings. The rest will come with experience and time.
Hey I’m from Germany 🙌🏻 I’m very happy that I found you! In all German Shops you can’t find Transformer Items like the Laminates or the Bobbin. I’m also very happy that I found your online shop! Please keep doing your great work! Greetings from Germany 🇩🇪
Based on your video I decided to purchase one of those winding machines for making some AC flybacks. Works excellent and I highly recommend one for any small coil winding application.
The counter could be a little bit better, you have to pay attention to reset it properly, but overall it is a really good way to wind anything. For more precise work it is good to make some kind of transport but even full free hand is fine for most applications.
Howdy. About the OPT for KT88 Push-Pull. After much experimentation I arrived at these conclusions. 1. The aim should be to achive full occupation of the winding window. I started with minimum thread gauges for design power. That left some two cm2 of unoccupied window. I rewound with one gauge thicker threads. Almost full occupation was achieved. 2. The primary should be split into two parts. One part should be the innermost winding and the other part should be the outermost winding. Alternatively the primary could be two full windings connected in parallel. This is probably the best way. Obeserve though that the current split will not be quite even. The thread should be one gauge thicker than half the one winding equivalent. 3. Overhead plastic (Xerox film) strips as winding layer isolation worked well. The strips were cut to be 0,5 - 1mm wider than the bobbin inner width. The strips were rigid enough not to wrinkle in the middle and yet flexible enough to form a kind of levies or ridges or dikes ( I don't know which word would be the best to describe ) along the strip sides preventing turns from collapsing inwards while winding. Anti-collapse is mandatory. Before assembling the strips Gorilla Superglue was applied along the strip sides. Two layers of strips were used to isolate the secondary from the other windings for good shock protection. 4. The windings from the innermost to the outermost: a. 1/4 of the primary b. 1/4 of the primary c. the 4 ohm secondary d. the 8 ohm additional secondary e. 1/4 of the primary f. 1/4 of the primary Windings a. and f. are connected in series to be one half of the primary. And b. and e. to be the other half. Very good DC resistance symmetry is achived. 5. A window gap of about 2mm remained unoccupied. Pieces of plastic were inserted into the window gaps. Plastics are slightly diamagnetic. The pieces will reduce the flux leakage somewhat. In high regards.
I always was curious how my winder winded the failed transformers I gave him to rewind for me. Now I know how and realized that what he charged me was well worth paying as it needs quite some patience, time and dedication. I wouldn't do it myself though I worked in the electronics repair field.
Definitely not a walk in the park, but as with most things in life, once you get a bit of routine it becomes a lot easier. It is time consuming and rewinding/rebuilding is even more complicated than winding from scratch.
Thank you for this very informative video and also all the information you give in your comments below. Yes, I did read them all and learned a few more things. I've bookmarked your website and I'll see if I can mnake a purchase soon.
Thanks! The bee's wax is nice touch. We need to find a cheap solution for vacuum chamber the wax/potting process. Power transformer still intimidates me :D I was scared enough putting DC onto my gapped class A
Thank you, Ben! I've seen people using old preasure cookers for potting but I really don't think it is necessary. Well, it is good to be careful with power transformers and take them seriously because if they are made properly they are extremly reliable and safe but if they are made with poorly isolated cheap and under ratet wire or with no insulation between primary and secondary at least then they can burst into flames. Another good benefit of bee's wax is that it doesn't ignite or burn really it handles temperature very well as you can see in the real old pure beeswax candles.
Well, it depends on how many of them you are using. The B+ is very low, the number of filaments would determine the most of the power consumption. You could probably use EI-66 metric or EI-86 I think is the imperial equivalent. If you have my power transformer calculator spreadsheet you can determine the exact dimensions you need according to the taps you need.
Great video. I just purchased your Simple PP OPT Calculator Spreadsheet. Question regarding "Window lenght and width? Which particular dimensions are these from the EI Sizing charts. For eg. If i want to go with the EI75(25x40) laminations, what will be the Window length and Width? Where do i find that from?
Thank you! You can watch my video on top ten transformer winding questions where I explained it. For EI75 metric it would be 3.75 lenght, and 1,25cm width.
Im in the process of rewinding a 720V pentode power transformer. Ive completed the windings but the original design must have been incredibly tight, it was hard to take the E's out a the windings were very tight against the E's. So now I'm having to compress the windings to get the E's in without damaging the insulation, so far so good but I am very surprised at how tight my version is. I used thinner insulation hoping that would give me a little more allowance on the layers but it doesn't appear to have worked. I was about 5 turns short on each layer unfortunately. Still I think I can fit it, I hope so as its goin 1654 secondary turns very carefully laid so I really don't want to do that again as it took days on and off.
excelente! thanks a lot!!! please a tutorial of SE trafo winding example would be perfect! I am waiting for your update of the interleave SE spreadsheet calculator!!!. I want to use that for wind SE output Trafos for my vintage replica of 5W to 15 W Champ amp or so and multiple secundaries like 4 and 8ohms. A question, in many countries is so dificult to know the quality or the origin of the E and I´s, that's what you can buy or can get "by hand" (recycled laminations of old trafo); So, what would you recommend? the value of 9400 Gauss (Magnetic flux density) as to have a margin of correction and efficiency? Best regards
I tried beeswax but it’s not ideal for the line level application I’m winding for. I use MG Chemicals 419D to fix my lams together, available here in The States. 10:25 I burn my enamel off with a lighter, and then tin it. It works well with 29 gauge. 34 gauge not so much.
Hi Matt, I've used the beeswax on line level transformers as well and it works fine for me. What kind of problems do you run into? I've checked the chemical you use it is available here in Europe as well so I might give it a try as well. For the thinner gauges I use a fine grit sandpaper and very carefully and gently run the wire between two folded sides. That works well but it takes a bit of practice. The lighter works as well.
Delatsch I build a commercially available product using an M6 EI63 laminate, and I wind everything in house. Beeswax smells nice and its great for marketing, but I had trouble with it in my shipping tests. It was too easy to separate the E and I sections if the package got dropped or damaged. So I researched and switched to the MG product. Thanks for the tip on fine gauge wires! I love the channel.
Nice to hear that! Would love to see what kind of equipment you are building. If you want to share it here feel free, or if you prefer it that way please send a private message to my facebook page. Yeah, it's funny that people put higher price on products that use beeswax and yet it is cheaper than any other transformer or coil resin.
Delatsch I build some pro audio stuff, a few tube mic preamps, a microphone with a toroid output transformer that I wind myself, and some DSP based 500 series modules that use EI63 cores that I also wind. I’ll send you a PM on the FB page.
Hi. Just got your calculator. I’ll check it out later today. I’m in the US. Where can I buy all the parts to make the transformers (bobbins, laminations)? I know the wire. Thanks.
Where are you buying parts to make transformers? I’m trying to make some transformers in sizes ranging from ei 75 to ei150. I can’t find out where to buy parts( bobbins wire ei laminations. ). Please help.
@@csandoval82 bobbins, kepton tape, wires on ebay. Laminations are hard to get. I was lucky to be able to buy few amounts but haven’t been able to get more.
I am confused, doesnt a transformer usualy have 2 windings (at least i saw that in microwave) Also what kind of transformer would I need for a linear power supply? (Like can I make this type or does it have to have 2coils like a microwave one?) Also, why do you need to pot it? (Then its hard to fix if it breaks) Do you maybe know what type of a transformer does a pre-heat flurescent ballast have? (When they break you are in trouble, because you cannot fix them since they are potted, and you cannot buy new ones, because noone makes them anymore (at least finding 220V T12 ones is a problem) and people want you to forget about them because they are not efficiant or something)
@@23kazliukas I don't have experience with it, but I think you can try with 12000Gs and since it is easy to insert the core, you can make a test with a simple transformer for your mains voltage as a primary and 100 turns for secondary and see what you will get.
Hi Delatsch! i have korean big scrap transformer, there are 3 wire each at the primer and seconder. Third ones should be body / ground connection of the owen. Just to test it i apply about 3 or 12 ac to both coils (primer ot seconder coils) then my source transformer is overheated. that means korean transformer is out of order or the higher temp is normal for that kind of transformer?
This is great! Nice work. I have wanted to wind transformers for quite a while. I have two questions: Have you tested your spreadsheets to see if they work in LibreOffice Calc (This is an open source spreadsheet program - I run Linux only and this is pretty standard on many distributions)? For the screws that hold the transformer together, I always thought you needed to isolate them from the lamination's?
Thank you! Yes, the sheets work I've used it myself in Libre Office as well. They also work in Google Sheets on the Chrome boxes and Apple Numbers and of course in MS Excel as well.
Nice video. There are also double bobbin transformers with separate windings for primary and secondary coils on separate bobbins. I wonder what are their efficiency compared to single bobbin transformer. I wanted to make a double bobbin transformer with 12 0 12V and 0 10V outputs and 220V input.
It is for a 12 0 12v 0 and 5/10V 1.5A transformer with 230V AC input. The input with primary winding has two wires, the secondary winding with output has 5 output wires. I was planning to put the secondary winding on a separate bobbin. These are bobbins are smaller than a single bobbin. The secondary windings are probably less than 170 turns of wire gauge 25. The primary may have 2000 tuns of wire gauge 38/36. This is a rough estimate.
Well, I presume you would like to amplify some audio signal? Usually it is done with a step up transformer that amplifies a signal in 1:10 (vintage ones went up to 1:20) and then you use an active device to amplify the signal further. The transformer is useful for these applications because it doesn't have internal noise like active devices and it can match the impedance. So, you can match the impedance and amplify the first most critical portion of the signal and then feed it to an active device like a jfet, opamp or tube.
@@ColocasiaCorm The first problem is that you need a specialised high permeability core to reduce the number of turns. But with this ratio, even with the highest permeability core you would still need like 800000 turns on the secondary :) If you would increase the core size it would get veeery expensive and still you would need too many turns on the secondary which would cause a lot of leakage inductance and stray capacitance that would kill you high frequency response totally.
i have a question. does winding pattern affects efficiency? as I have seen in other youtube they wind the wirings in a pattern of going from top to bottom and vice versa forming a layer before going another direction. and in your video you just let the wire be evenly paced on the surface of the bobbin.
Ideally you should go from left to right to make windings more uniform. It is more important in hifi transformers, in guitar amplifier transformers it is not really going to be noticeable since it effect higher spectre of frequencies.
Wow good job. Where do you get all your bobbins wire and EI type laminations. I’m having a hard time finding a supplier. I have about 20 transformers I need to wind and I don’t have any parts. Any help would be greatly appreciated
I notice that the wire springs out a lot between the corners of the bobbin preventing a complete fill. Are there any techniques to keep the wire flatter against the bobbin and achieve a higher wire fill percentage? I am having this problem on the diy transformer that I am working on. Thanks for the good video.
When hand winding the only way to reduce that is to put higher tension on the wire (without burning the fingers :) ) and also to keep hands as close to the bobbin for better control. On automated winders a good transport gets rid of that. But with my calculator, when the calculated stack fill is at around 85-90 percent you should have no problem fitting the wire. It's better to have a bit of room, than not to be able to fit the wire and then have to throw it. Thanks for the comment.
Is it 540-0-540 or 270-0-270? If it is 540-0-540 then I would recommend putting layer of insulation between each layer. Otherwise the process is the same. And double coated motor wire is a must.
I get them locally here in Europe, you should be able to get them in motor parts store, but usually they are sold in bulk for companies rather than in small quantities unfortunately.
I'm a bit confused about measuring the core size. Is it the bobbin, or the overall area that the bobbin + winding would fit into once the laminations are put together?
The core size is just a x b of the bobbin hole. The winding window area of the bobbin is not important for the number of turns, it is just calculated to see if you will be able to fit the amount of wire you calculated to that particular bobbin. Not to start winding and realize half way through that the wire won't fit.
@@Delatsch Thanks for the reply. Another question I have. So, on the calculator spreadsheet you made, e.g. the wire thickness says 1.13MM, but this isn't a standard size wire. So, would I just go with 1.15MM wire then?
@@in.der.welt.sein. Yes, just use the next standard wire size. If it would be something like 0.21, you could round it down to 0.2mm, but it's usually better to go with the slightly higher value to avoid excess heat in the windings.
It doesn't really make a difference, the important thing is to have the primary and secondary as close to each other when interleaving, but you can start with any.
It can be used to calculate output transformer for a tube microphone or transistor microphone if you know the impedances, but if you mean the output transformers used in dynamic microphones like Shure 58 then it won't work right because there are other design differences which need to be considered.
The app is still not on App Store, but will be soon. You can check the spreadsheet versions of the calculator on my website. It works for standard E-I type laminations for power transformers and also line and power output transformers for both SE and PP applications.
You can use transformer resins and similar products to pot the transformer, but if you don't pot it in any way it will buzz loudly at mains frequency 50 or 60hz.
In the old days it used to be a concern. With modern transformer wire which is double coated and can withstand 200+ degrees C and 5kv+ it is impossible to happen (that's two coats on each side of each wire). It makes sense between separate windings just in case and for sure between primary and secondary as a safety precaution. It should also be used for higher voltage transformer in the kV range, but for relatively low voltages it is not needed. Been winding for years and never had that issue.
Of course this can still happen. Check the voltage rating of grade 2 or even grade 3 magnet wire from Elekrisola. Very renowned manufacturer, still the voltage rating is below 230V for those. At the very least, this should be mentioned. I'm sure most people watching this are not aware of this issue at all.
Wire with insulation that can only withstand 230V shouldn't be used in transformers. Even if you put layer insulation you still have wires of the same layer next to each other. The voltage breakthrough can happen there just the same. In my written tutorials I always mention that only double coated transformer or motor wire should be used for transformer winding. It is not possible to mention all the details and problems of transformer winding in one short video. As I said, never had a voltage breakthrough, the only time I saw transformer fail is when there was a dead short in the circuit and no fuse was present.
There is no online place that sells in reasonable quantities. You can check my website as well, but the best would be to contact me directly since I have more options than currently visible on the site. You can write me on my facebook page or on the website.
I don't really understand why people will put some much time and effort in to winding pickups but then buy an off the shelf machine wound output transformer. 🤷Scatter wound, not potted and not too much tension has to equate to a richer and more complex final "tone".
Scatter wound just means you are wasting copper wire. All it does is weaken the flux density of the coil, which means it takes more copper in a scatter wound coil to equal the same flux density in a uniform one. If you want a weaker flux density in a uniform coil, use less windings and save money on wire. lol
You stack up all the E laminations from one side first and the I laminations from the other. Then you use a thin piece of pressed paper in between the E stack and the I stack.
@@Delatsch Many thanks for the quick answer. Is the thickness of the paper important? Is it calculated on your spreadsheet? How do you fasten the I laminations to the E lamination in this case?
Yes, thickness of paper is important. It can be calculated but calculations are not useful for practical purposes. It has to be tested in practice using a circuit similar for testing chokes with DC current. It's not possible to explain it in a comment. I might do a video in the future explaining the process.
I've bought it off ebay. If you search for NZ-1 coil winder you will find it. It works well, but from time to time it might have issues with a counter not switching to a next hundred or a thousand :) Other than that it has served me well for years. I might add another reed switch counter just to have the backup in case i need to reset this one during the winding.
Thanks! You can find a lot of the basic materials, core laminations and wire on my website, if you are in the EU it can be a good bargain since the shipping is relatively cheap and there are no customs. You can check it out here: www.delatsch.com/ If there is anything else you might need and don't find it on the website, feel free to contact me on the contact page there or via my facebook page.
@@Delatsch Can the spreadsheet calculator help my issue. I have a push pull headphone amplifier that uses two valves as output to the transformer primary. So the primary will have a DC voltage of 135VDC always across it supplying the anodes of the two valves via a center tap. The output impedance to match from the valves output to the primary winding is 10kohms. The secondary winding needs an output impedance of 400ohms to suit my monitor headphones. So what I need the calculator to tell me is the SWG or AWG gauge wires to use and quantity of wire, dimensions etc. Can it help me?
@@TechTins_Projects Yes, that's exactly what it does. Currently it only calculates the wire thickness in mm, but you can easily convert it to AWG using online charts. The iOS version calculates in AWG directly and the new upcoming version of the spreadsheet calculator will have it as well. Of course, if you purchase the calculator now you will get the updated version for free once it's ready.
@@Delatsch All I want to specify as inputs is power output from tubes plus output impedance of tubes and the input impedance of my headphone amps. In other words I only have following data. Power=1.8Watts Zin = 10kOhms Zout=400ohms I = 13mA. Can the spreadsheet then give me all other calculations:- turns needed, wire gauge, height of windings number of layers needed for given wire gauge, type of bobbin etc etc.
FREAKING EXACTLY WHAT I WAS LOOKING FOR! Thanks.
Thanks, happy that it was useful!
Thanks, Delatsch. I'm about to start my first transformer and just came back here to make sure I'm ready.
Thank you and good luck!
Nice video. A few suggestions to help with high percentage bobbing fills.
1) Keep all tape on the front or back side of the bobbin. Even just a few thousandths in the lamination areas add up quickly.
2) Keep winding layers neat, gaps and overlaps will cause uneven layers and eat up space very quickly.
3) Keep overlap for paper layers to around 250 thousandths and make sure all internal paper layer seams are on the front or rear faces.
4) Eliminate the heat shrink tubing and instead partially strip the lead wire leaving the insulation stub on the end of the lead wire. Strip the insulation off of the magnet wire and wrap it around the exposed lead wire conductors. Solder in place. Tape the lead wire to the bobbin and make sure the lead wire stretches across the entire width of the bobbin. Doing this will result in a more stable uniform winding layer. Do the same when you finish the winding and the second lead wire. Use your judgement when determining when to bury lead wires or bring out the windings. If the diameter of the winding wire is less than the thickness of the lead wire insulation, it should be fine to bury the leads.
Thank you for your input! It's difficult to have a definite answer for some of the winding techniques since there are many ways to go about it and many different situations and conditions that will call for something different every time. The most important thing is for the "amateur" winder is to make sure the transformer will be safe, use only two coat enamel wire where the insulation can withstand high voltage and high temperature and the second objective is to fit the wire so that the laminations can be inserted without rubbing on the finished windings. The rest will come with experience and time.
What an excellent video. You have demystified a very interesting subject to us ampoholics. And opened up a whole new rabbit hole! Thank you!
Thank you very much for your kind words!
Hey I’m from Germany 🙌🏻
I’m very happy that I found you! In all German Shops you can’t find Transformer Items like the Laminates or the Bobbin. I’m also very happy that I found your online shop! Please keep doing your great work!
Greetings from Germany 🇩🇪
Thank you for your kind words! Please contact me if you don't find something in the online store and you need it.
Hello from Nevada, USA. Superb wormanship and great video. Thanks for taking the time to produce this excellent video!
Thank you!
Nice video! I'm sat here trying to wind a HV transformer with 0.2mm wire by hand :)
Good luck with the winding!
Fantastic! I love the beeswax impregnation, nice touch.
Thank you! Glad you've liked it!
Based on your video I decided to purchase one of those winding machines for making some AC flybacks. Works excellent and I highly recommend one for any small coil winding application.
The counter could be a little bit better, you have to pay attention to reset it properly, but overall it is a really good way to wind anything. For more precise work it is good to make some kind of transport but even full free hand is fine for most applications.
Howdy.
About the OPT for KT88 Push-Pull. After much experimentation I arrived at these conclusions.
1. The aim should be to achive full occupation of the winding window. I started with minimum thread gauges for design power. That left some two cm2 of unoccupied window. I rewound with one gauge thicker threads. Almost full occupation was achieved.
2. The primary should be split into two parts. One part should be the innermost winding and the other part should be the outermost winding. Alternatively the primary could be two full windings connected in parallel. This is probably the best way. Obeserve though that the current split will not be quite even. The thread should be one gauge thicker than half the one winding equivalent.
3. Overhead plastic (Xerox film) strips as winding layer isolation worked well. The strips were cut to be 0,5 - 1mm wider than the bobbin inner width. The strips were rigid enough not to wrinkle in the middle and yet flexible enough to form a kind of levies or ridges or dikes ( I don't know which word would be the best to describe ) along the strip sides preventing turns from collapsing inwards while winding. Anti-collapse is mandatory. Before assembling the strips Gorilla Superglue was applied along the strip sides. Two layers of strips were used to isolate the secondary from the other windings for good shock protection.
4. The windings from the innermost to the outermost:
a. 1/4 of the primary
b. 1/4 of the primary
c. the 4 ohm secondary
d. the 8 ohm additional secondary
e. 1/4 of the primary
f. 1/4 of the primary
Windings a. and f. are connected in series to be one half of the primary. And b. and e. to be the other half. Very good DC resistance symmetry is achived.
5. A window gap of about 2mm remained unoccupied. Pieces of plastic were inserted into the window gaps. Plastics are slightly diamagnetic. The pieces will reduce the flux leakage somewhat.
In high regards.
I always was curious how my winder winded the failed transformers I gave him to rewind for me. Now I know how and realized that what he charged me was well worth paying as it needs quite some patience, time and dedication. I wouldn't do it myself though I worked in the electronics repair field.
Definitely not a walk in the park, but as with most things in life, once you get a bit of routine it becomes a lot easier. It is time consuming and rewinding/rebuilding is even more complicated than winding from scratch.
@@Delatsch 👍
muito bom seu projeto , também ja enrolei alguns transformadores aqui . parabéns
Thank you!
Thank you for this very informative video and also all the information you give in your comments below.
Yes, I did read them all and learned a few more things.
I've bookmarked your website and I'll see if I can mnake a purchase soon.
Thank you for your kind words!
What a fantastic instructional video!
Thank you! I'm really happy that it was helpful!
Thanks! The bee's wax is nice touch. We need to find a cheap solution for vacuum chamber the wax/potting process.
Power transformer still intimidates me :D
I was scared enough putting DC onto my gapped class A
Thank you, Ben! I've seen people using old preasure cookers for potting but I really don't think it is necessary. Well, it is good to be careful with power transformers and take them seriously because if they are made properly they are extremly reliable and safe but if they are made with poorly isolated cheap and under ratet wire or with no insulation between primary and secondary at least then they can burst into flames. Another good benefit of bee's wax is that it doesn't ignite or burn really it handles temperature very well as you can see in the real old pure beeswax candles.
Thanks alot. I need to make transformer for tube equipment and those are not available anymore. Or at a very high costs.
Thank you!
Question: What is the most common size steel lamination and bobbin size for a power transformer that would be used with 12AX7 tubes?
Well, it depends on how many of them you are using. The B+ is very low, the number of filaments would determine the most of the power consumption. You could probably use EI-66 metric or EI-86 I think is the imperial equivalent. If you have my power transformer calculator spreadsheet you can determine the exact dimensions you need according to the taps you need.
Great video. I just purchased your Simple PP OPT Calculator Spreadsheet. Question regarding "Window lenght and width? Which particular dimensions are these from the EI Sizing charts. For eg. If i want to go with the EI75(25x40) laminations, what will be the Window length and Width? Where do i find that from?
Thank you! You can watch my video on top ten transformer winding questions where I explained it. For EI75 metric it would be 3.75 lenght, and 1,25cm width.
Nice work.
Thank you!
very good, thanks for sharing.
Thank you!
Im in the process of rewinding a 720V pentode power transformer. Ive completed the windings but the original design must have been incredibly tight, it was hard to take the E's out a the windings were very tight against the E's. So now I'm having to compress the windings to get the E's in without damaging the insulation, so far so good but I am very surprised at how tight my version is. I used thinner insulation hoping that would give me a little more allowance on the layers but it doesn't appear to have worked. I was about 5 turns short on each layer unfortunately. Still I think I can fit it, I hope so as its goin 1654 secondary turns very carefully laid so I really don't want to do that again as it took days on and off.
Nice, yes rewinding is a lot more difficult.than winding from scratch.
excelente! thanks a lot!!! please a tutorial of SE trafo winding example would be perfect! I am waiting for your update of the interleave SE spreadsheet calculator!!!. I want to use that for wind SE output Trafos for my vintage replica of 5W to 15 W Champ amp or so and multiple secundaries like 4 and 8ohms.
A question, in many countries is so dificult to know the quality or the origin of the E and I´s, that's what you can buy or can get "by hand" (recycled laminations of old trafo); So, what would you recommend? the value of 9400 Gauss (Magnetic flux density) as to have a margin of correction and efficiency? Best regards
Thank you! I will post a tutorial on SE transformers soon.
I tried beeswax but it’s not ideal for the line level application I’m winding for. I use MG Chemicals 419D to fix my lams together, available here in The States.
10:25 I burn my enamel off with a lighter, and then tin it. It works well with 29 gauge. 34 gauge not so much.
Hi Matt,
I've used the beeswax on line level transformers as well and it works fine for me. What kind of problems do you run into?
I've checked the chemical you use it is available here in Europe as well so I might give it a try as well. For the thinner gauges I use a fine grit sandpaper and very carefully and gently run the wire between two folded sides. That works well but it takes a bit of practice. The lighter works as well.
Delatsch I build a commercially available product using an M6 EI63 laminate, and I wind everything in house.
Beeswax smells nice and its great for marketing, but I had trouble with it in my shipping tests. It was too easy to separate the E and I sections if the package got dropped or damaged. So I researched and switched to the MG product.
Thanks for the tip on fine gauge wires! I love the channel.
Nice to hear that! Would love to see what kind of equipment you are building. If you want to share it here feel free, or if you prefer it that way please send a private message to my facebook page. Yeah, it's funny that people put higher price on products that use beeswax and yet it is cheaper than any other transformer or coil resin.
Delatsch I build some pro audio stuff, a few tube mic preamps, a microphone with a toroid output transformer that I wind myself, and some DSP based 500 series modules that use EI63 cores that I also wind. I’ll send you a PM on the FB page.
Cool, looking forward to the links to your page!
Brilliant! Thanks so much:)
Thank you!
Hi. Just got your calculator. I’ll check it out later today. I’m in the US. Where can I buy all the parts to make the transformers (bobbins, laminations)? I know the wire. Thanks.
Where are you buying parts to make transformers? I’m trying to make some transformers in sizes ranging from ei 75 to ei150. I can’t find out where to buy parts( bobbins wire ei laminations. ). Please help.
@@csandoval82 bobbins, kepton tape, wires on ebay. Laminations are hard to get. I was lucky to be able to buy few amounts but haven’t been able to get more.
I am confused, doesnt a transformer usualy have 2 windings (at least i saw that in microwave)
Also what kind of transformer would I need for a linear power supply? (Like can I make this type or does it have to have 2coils like a microwave one?)
Also, why do you need to pot it? (Then its hard to fix if it breaks)
Do you maybe know what type of a transformer does a pre-heat flurescent ballast have? (When they break you are in trouble, because you cannot fix them since they are potted, and you cannot buy new ones, because noone makes them anymore (at least finding 220V T12 ones is a problem) and people want you to forget about them because they are not efficiant or something)
Práctical POWER transformer winding tutorial
Hi. Just got your calculator app. I’m in US. Where can I get the bobbins and laminations? Thanks.
nice!
Hi, nice work! How about c core transformer calculations?
The formulas are the same, just the core section is one leg cross section.
@@Delatsch Thanks for reply, will use your calculation for my project. What do you think optimal Gauss input would be for nanocrystaline core?
@@23kazliukas I don't have experience with it, but I think you can try with 12000Gs and since it is easy to insert the core, you can make a test with a simple transformer for your mains voltage as a primary and 100 turns for secondary and see what you will get.
Can you please send me details of output transformer winding details of el34 tubes in push pull configuration thanks
Hi Delatsch! i have korean big scrap transformer, there are 3 wire each at the primer and seconder. Third ones should be body / ground connection of the owen. Just to test it i apply about 3 or 12 ac to both coils (primer ot seconder coils) then my source transformer is overheated. that means korean transformer is out of order or the higher temp is normal for that kind of transformer?
now where the hell do i get all that stuff/?/?
I want to wind 100 and 200 watt em transformers where and what size cores should i buy
Can you make a same style tutorial for toroidal transformer? Maybe also show us how to make the toroidal core using foil tape.
I don't currently wind toroidal transformers, I am planning on winding some toroidal inductors in the future.
I have a few I need repaired, can I potentially send them to you?
This is great! Nice work. I have wanted to wind transformers for quite a while. I have two questions: Have you tested your spreadsheets to see if they work in LibreOffice Calc (This is an open source spreadsheet program - I run Linux only and this is pretty standard on many distributions)? For the screws that hold the transformer together, I always thought you needed to isolate them from the lamination's?
Thank you! Yes, the sheets work I've used it myself in Libre Office as well. They also work in Google Sheets on the Chrome boxes and Apple Numbers and of course in MS Excel as well.
BRILLIANT
Thank you!
Where do you get the transformer plates and core sir?
I get them locally here in Europe, but I've heard that Edcor is selling them on order, but usually for slightly larger orders.
Where do I find the steel for transformer
If you are in the EU or nearby, check out my website for laminations and bobbins.
Nice! can we use a lighter to remove enamel by burning it?
Yes many people do it, but it might burn something else in the process, melt the bobbin etc. so I wouldn't recommend it.
Nice video. There are also double bobbin transformers with separate windings for primary and secondary coils on separate bobbins. I wonder what are their efficiency compared to single bobbin transformer. I wanted to make a double bobbin transformer with 12 0 12V and 0 10V outputs and 220V input.
It provides natural.insulation between primary and the secondary, but it is not practical for transformers with more secondary windings.
It is for a 12 0 12v 0 and 5/10V 1.5A transformer with 230V AC input. The input with primary winding has two wires, the secondary winding with output has 5 output wires. I was planning to put the secondary winding on a separate bobbin. These are bobbins are smaller than a single bobbin. The secondary windings are probably less than 170 turns of wire gauge 25. The primary may have 2000 tuns of wire gauge 38/36. This is a rough estimate.
Im thinking of winding a step up transformer to step up from 1mv to 2V. Would i really need 1:2000 winding ratio? Seems ridiculous
Well, I presume you would like to amplify some audio signal? Usually it is done with a step up transformer that amplifies a signal in 1:10 (vintage ones went up to 1:20) and then you use an active device to amplify the signal further. The transformer is useful for these applications because it doesn't have internal noise like active devices and it can match the impedance. So, you can match the impedance and amplify the first most critical portion of the signal and then feed it to an active device like a jfet, opamp or tube.
@@Delatsch but why is 1:10 possible and not 1:1000
@@ColocasiaCorm The first problem is that you need a specialised high permeability core to reduce the number of turns. But with this ratio, even with the highest permeability core you would still need like 800000 turns on the secondary :) If you would increase the core size it would get veeery expensive and still you would need too many turns on the secondary which would cause a lot of leakage inductance and stray capacitance that would kill you high frequency response totally.
@@Delatsch i love you.
Where did you get the core laminations? It's almost impossible to find ones alone, not as a pre built transformer
It depends on where you are located at, if you are in the EU you can check my website.
i have a question. does winding pattern affects efficiency? as I have seen in other youtube they wind the wirings in a pattern of going from top to bottom and vice versa forming a layer before going another direction. and in your video you just let the wire be evenly paced on the surface of the bobbin.
Ideally you should go from left to right to make windings more uniform. It is more important in hifi transformers, in guitar amplifier transformers it is not really going to be noticeable since it effect higher spectre of frequencies.
Wow good job. Where do you get all your bobbins wire and EI type laminations. I’m having a hard time finding a supplier. I have about 20 transformers I need to wind and I don’t have any parts. Any help would be greatly appreciated
I get them locally in Europe. You can check my website for some basic stuff. www.delatsch.com
I notice that the wire springs out a lot between the corners of the bobbin preventing a complete fill. Are there any techniques to keep the wire flatter against the bobbin and achieve a higher wire fill percentage? I am having this problem on the diy transformer that I am working on. Thanks for the good video.
When hand winding the only way to reduce that is to put higher tension on the wire (without burning the fingers :) ) and also to keep hands as close to the bobbin for better control. On automated winders a good transport gets rid of that. But with my calculator, when the calculated stack fill is at around 85-90 percent you should have no problem fitting the wire. It's better to have a bit of room, than not to be able to fit the wire and then have to throw it. Thanks for the comment.
Thank you
Would you recommend these techniques for high voltage transformers? I’m looking to rewind a transformer with secondaries of 540v.
Is it 540-0-540 or 270-0-270? If it is 540-0-540 then I would recommend putting layer of insulation between each layer. Otherwise the process is the same. And double coated motor wire is a must.
where do you buy those laminations? Is there a way to get custom ones for say, building a motor stator?
I get them locally here in Europe, you should be able to get them in motor parts store, but usually they are sold in bulk for companies rather than in small quantities unfortunately.
Where can I find information regarding the standards governing the various core sizes? E.G. how tall/wide/deep is an EI-120, etc?
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I'm a bit confused about measuring the core size. Is it the bobbin, or the overall area that the bobbin + winding would fit into once the laminations are put together?
The core size is just a x b of the bobbin hole. The winding window area of the bobbin is not important for the number of turns, it is just calculated to see if you will be able to fit the amount of wire you calculated to that particular bobbin. Not to start winding and realize half way through that the wire won't fit.
@@Delatsch Thanks for the reply. Another question I have. So, on the calculator spreadsheet you made, e.g. the wire thickness says 1.13MM, but this isn't a standard size wire. So, would I just go with 1.15MM wire then?
@@in.der.welt.sein. Yes, just use the next standard wire size. If it would be something like 0.21, you could round it down to 0.2mm, but it's usually better to go with the slightly higher value to avoid excess heat in the windings.
For step up transformer, what should be the first to wind on the bobbin? Primary or secondary??
It doesn't really make a difference, the important thing is to have the primary and secondary as close to each other when interleaving, but you can start with any.
@@Delatsch auhmmnn... Ok thanks.. 😊
Is it possible to use your calculator to calculate small microphone output transformer?
It can be used to calculate output transformer for a tube microphone or transistor microphone if you know the impedances, but if you mean the output transformers used in dynamic microphones like Shure 58 then it won't work right because there are other design differences which need to be considered.
Does your spreadsheet app work for any type of transformer, e.g. EHT, output, matching, power, etc?
The app is still not on App Store, but will be soon. You can check the spreadsheet versions of the calculator on my website. It works for standard E-I type laminations for power transformers and also line and power output transformers for both SE and PP applications.
Is the beeswax absolutely necessary? What happens without it, leaving the transformer as is? Thanks
You can use transformer resins and similar products to pot the transformer, but if you don't pot it in any way it will buzz loudly at mains frequency 50 or 60hz.
What about layer insulation? Without that, voltage breakthroughs are likely to become a problem.
In the old days it used to be a concern. With modern transformer wire which is double coated and can withstand 200+ degrees C and 5kv+ it is impossible to happen (that's two coats on each side of each wire). It makes sense between separate windings just in case and for sure between primary and secondary as a safety precaution. It should also be used for higher voltage transformer in the kV range, but for relatively low voltages it is not needed. Been winding for years and never had that issue.
Of course this can still happen. Check the voltage rating of grade 2 or even grade 3 magnet wire from Elekrisola. Very renowned manufacturer, still the voltage rating is below 230V for those. At the very least, this should be mentioned. I'm sure most people watching this are not aware of this issue at all.
Wire with insulation that can only withstand 230V shouldn't be used in transformers. Even if you put layer insulation you still have wires of the same layer next to each other. The voltage breakthrough can happen there just the same. In my written tutorials I always mention that only double coated transformer or motor wire should be used for transformer winding. It is not possible to mention all the details and problems of transformer winding in one short video. As I said, never had a voltage breakthrough, the only time I saw transformer fail is when there was a dead short in the circuit and no fuse was present.
Where is best to get supplies from in Europe for the bobbins, laminations and tape etc ?
There is no online place that sells in reasonable quantities. You can check my website as well, but the best would be to contact me directly since I have more options than currently visible on the site. You can write me on my facebook page or on the website.
@@Delatsch Great - thanks. 🙂
is the laminations made out of standard alimunium ?
The laminations are silicon steel.
I don't really understand why people will put some much time and effort in to winding pickups but then buy an off the shelf machine wound output transformer. 🤷Scatter wound, not potted and not too much tension has to equate to a richer and more complex final "tone".
Haha, yeah. Well, it doesn't work quite the same in the output transformers, but still a good point.
Scatter wound just means you are wasting copper wire. All it does is weaken the flux density of the coil, which means it takes more copper in a scatter wound coil to equal the same flux density in a uniform one. If you want a weaker flux density in a uniform coil, use less windings and save money on wire. lol
Where can you buy that wrapping machine?
You can find it on Ebay.
If the transformer is for single ended audio final, how do you insulate the I from E pieces?
You stack up all the E laminations from one side first and the I laminations from the other. Then you use a thin piece of pressed paper in between the E stack and the I stack.
@@Delatsch Many thanks for the quick answer. Is the thickness of the paper important? Is it calculated on your spreadsheet? How do you fasten the I laminations to the E lamination in this case?
Yes, thickness of paper is important. It can be calculated but calculations are not useful for practical purposes. It has to be tested in practice using a circuit similar for testing chokes with DC current. It's not possible to explain it in a comment. I might do a video in the future explaining the process.
@@Delatsch Many thanks!
Where did you buy the winding machine?
I've bought it off ebay. If you search for NZ-1 coil winder you will find it. It works well, but from time to time it might have issues with a counter not switching to a next hundred or a thousand :) Other than that it has served me well for years. I might add another reed switch counter just to have the backup in case i need to reset this one during the winding.
@@Delatsch Thanks!!
You are welcome!
why not use paraffin instead of bee wax?
I also didn't appreciate that you has put no isulation on screws.
Because paraffin wax is highly flammable, stinks and it is a petroleum product. Bee's wax is a natural material which has no downsides in my opinion.
And there is no need for insulation on the screws.
Nice video...thanks.
Do you know where i can buy high quality transformer components online.
If anyone knows please let me a note.
Thanks! You can find a lot of the basic materials, core laminations and wire on my website, if you are in the EU it can be a good bargain since the shipping is relatively cheap and there are no customs. You can check it out here:
www.delatsch.com/
If there is anything else you might need and don't find it on the website, feel free to contact me on the contact page there or via my facebook page.
Where would you suggest finding parts in the US.?
Where do you get the laminations from?
I get them in bulk locally, you can check my website I have some for sale if you are in the EU.
@@Delatsch Can the spreadsheet calculator help my issue. I have a push pull headphone amplifier that uses two valves as output to the transformer primary. So the primary will have a DC voltage of 135VDC always across it supplying the anodes of the two valves via a center tap. The output impedance to match from the valves output to the primary winding is 10kohms. The secondary winding needs an output impedance of 400ohms to suit my monitor headphones.
So what I need the calculator to tell me is the SWG or AWG gauge wires to use and quantity of wire, dimensions etc. Can it help me?
@@TechTins_Projects Yes, that's exactly what it does. Currently it only calculates the wire thickness in mm, but you can easily convert it to AWG using online charts. The iOS version calculates in AWG directly and the new upcoming version of the spreadsheet calculator will have it as well. Of course, if you purchase the calculator now you will get the updated version for free once it's ready.
@@Delatsch All I want to specify as inputs is power output from tubes plus output impedance of tubes and the input impedance of my headphone amps. In other words I only have following data.
Power=1.8Watts
Zin = 10kOhms
Zout=400ohms
I = 13mA.
Can the spreadsheet then give me all other calculations:- turns needed, wire gauge, height of windings number of layers needed for given wire gauge, type of bobbin etc etc.
@@TechTins_Projects That's all the data you need. Yes, it will calculate the rest for you.
Where can I find your email
You can write me via contact form on my website or on my facebook page.
How to buy your transformer calculator? I messaged you on Facebook. :)
You can buy the spreadsheets using this link: www.delatsch.com/shop/