Microwave Oven Transformer Rewind the Right Way, Too Many Dummies on here giving Bad Advice

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  • Опубліковано 19 сер 2024
  • Yes I am going to be very sarcastic here. I'm so tired of seeing misinformation here on YT in general, but yesterday I saw a Hamster's video showing people how to use an MOT to power their tube filaments. He then tells people how MOT's run hot and you need a Power Factor Correction Capacitor and a Fan to keep the transformer cool. What a Dummy, even with all that Goonie Goohoo BS, the transformer is still going to draw tons of power and overheat and burn up. And on top of that, draw an extra 9/10/or more amps!
    What I show here is a quick and sloppy example of how to put more windings on the primary and have the transformer operate cool, quiet, and efficiently.
    Every MOTransformer will be different, but all very similar. They are not designed to run anything other than wide open throttle. The Primary is under-wound and in addition the entire core and secondary is designed for wide open throttle full magnetic core saturation at all times. You will need to add about 33% more windings to the primary to make these transformers work with other projects. In most cases that means adding 40-50 more primary windings. I am not going to go into full details here about how to know the exact number of turns, but you can get pretty close just by testing the amp draw on the primary after every 10-15 winds. Remember to use "magnet wire" of the same gauge as the original primary and add the winding in the same direction as the original primary. First test amp draw with the original primary, then after about every 10-15 turns test again, the amp draw will get down pretty low as you approach 40-50 turns, if it starts going back up you passed the sweet spot. Cover sharp edges, don't scrape the coating off or you will have to start over.
    For the secondary, it depends on what you want to do, use an appropriate size/gauge of magnet wire or some high temp wire, again, the secondary depends what you need. The secondary side will be about 1 volt per turn, again, every MOT will be a little different.
    For this video, I just used some scrap wire to demonstrate. Do not use regular old scrap wire like me in this video. Use the correct stuff!
    In this video, this MOT started off using over 10 amps even with no load, after adding 40+ turns to the primary, it now barely uses 1 amp. I didn't count the exact number of turns and really didn't add quite enough. It was just where I got to when I ran out of wire LOL.

КОМЕНТАРІ • 163

  • @bigcbradio
    @bigcbradio  2 місяці тому +11

    ( edit: if you gave me a thumbs down on this video but you still use my advice, I will haunt you in your dreams🤣 ) otherwise....
    OK OK OK, I guess when I say in the first few minutes of this video that "I am the Expert" I was way too convincing with my attitude and have angered a few people. It was meant to be funny! I am NOT AN EXPERT, I repeat, NOT AN EXPERT... But I can tell you this, if you are going to rewind the average MOT and you do not add some windings to the primary, said transformer is going to use a lot of AMPS, it is going to use them ALL! (again, a joke). Even if you are not putting a heavy load on the secondary, the transformer is going to use a lot of amps and get very hot over time. If you are using it for something like a spot welder, where you are only going to switch it (the primary) on for a second at a time, and only a few times a minute, you will be fine, BUT if you are going to use it (your rewound MOT) for an extended period of time, such as a battery charger, a power supply, or for tube filaments in an amplifier, etc... you will need the extra windings, otherwise your MOT is going to get very HOT and use a lot of AMPs continuously (think electric bill). I created this video specifically because I ran across a HAM operators video describing how to use an MOT for a filament power supply, he does not add windings to the primary and is instead trying to fix the problem by adding a capacitor and a fan. That is bad advice, that fan cannot cool the inside of the windings, it adds extra unnecessary components, still draw wayy too many amps, and is just over all wrong.
    That being said, If you are going to chime in and tell me how I can do this better, please read my description where I specifically say this "is a quick and sloppy example"

    • @sempertard
      @sempertard 2 місяці тому +5

      >>>I repeat, NOT AN EXPERT...

    • @bigcbradio
      @bigcbradio  2 місяці тому

      @@sempertard Thanks for that

    • @ScandalistRick
      @ScandalistRick 2 місяці тому +2

      Damn it homie, after talking to you a bit I wished I wasn't right... I'm here for you brotha!

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@ScandalistRick HaHa, Thanks. I have my big boy pants on, and I may make another transformer video now.

    • @williamlangley2044
      @williamlangley2044 2 місяці тому +2

      I don't give you thumbs down!! I gave you thumbs 👍👍 up, because I found the same thing that you did and you encouraged me to work again with the transformer to build a multi tap transformer.

  • @MrCheeto01
    @MrCheeto01 2 місяці тому +3

    Until he mentioned his smoke alarm chirping I was distracted trying to determine which one of mine was chirping

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      LOL, maybe in my next video I should have sirens, and police saying "come out with your hands up"

  • @craignehring
    @craignehring 2 місяці тому +1

    Quite insightful, seeing is believing
    In high school shop class one of the projects was to build a mains powered transformer from scratch including cutting the lamentations and firing them to get that oxide coating

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      That sounds like a great school and a great teacher. Out here in California the local high school removed all the shop classes and at the grade schools they removed the tether ball poles, the monkey bars, and the slides, they only left the swings and a sand box, and the children are not allowed to play tag, or dodge ball, soccer, or football. The award ceremonies take hours because almost every child gets an award because they have 3 levels of honor roll now and a participation award. Ok, I will stop ranting, LOL, but, that does sounds like a great school and a great teacher. Have fun with transformers.

  • @whatelseison8970
    @whatelseison8970 2 місяці тому +4

    I can't understand why folks always say to throw out the old secondary. If you just run them backwards they put out 6 volts at a couple dozen amps. (Watch the output winding temperature!)
    You can cut the welds or not it doesn't matter as long as their well clamped back together when you run it. Cutting em just makes it a hell of a lot easier to get the shunts out of the core and free up a bit more wire from the fine winding to attach a lead to instead of having to attach one wire to the core to run it.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      Again folks, do not cut the welds. I even saw a video here on YT where the guy says "cut the welds with a hacksaw, it's easy" then he proceeds to use a high speed cutoff wheel to cut the welds. LOL. Have you ever tried cutting a weld with a hacksaw? If you have then you already know what I should say here. If you are one of those people that has to learn everything the hard way, then by all means, get yourself some MOT's and try it both ways, all 27 ways, Cut the welds, add primary turns, don't add turns, then you will know. But in all seriousness, do not play with, or even power up an MOT that still has a secondary winding on it unless you really know what you are doing, or you may DIE very quickly.

    • @KallePihlajasaari
      @KallePihlajasaari 2 місяці тому +2

      @@bigcbradio I think this commenter was proposing putting mains into the secondary and using the primary as a low voltage output. It certainly would not saturate the core but it will also not be able to provide the full 700-1000W of power with the excessive winding resistance.
      Your advice not to play with the secondary high voltage is good.
      The advice in your video is also sound, I have seen one other video and understand enough about transformer theory to know that it is a sound fix for the problem.
      Perhaps one day you can do a demo of feeding the primary with a good size Variac and graphing the voltage and current, with and without a load, before and after the added turns. You will be able to show how the current starts to clearly increase faster than the voltage when the core reaches saturation.
      Nice video, don't worry about the nay sayers, you are far from the most abrasive on YT and provide good information.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@KallePihlajasaari Thanks for the comments. I'm not worried about them, otherwise I would have my comments off, or screen them. There are 2 reasons I made this video in this way. One reason was because I almost feel bad every time I run across a video showing people how to just add windings as a secondary for a project. These MOT's draw a lot of current and these beginners are going to be turned off of this hobby if all they get is bad advice and their transformers get hot, burn up, blow fuses, etc.. and I want to help them enjoy this hobby. The second reason is because I have been involved in electronics in many capacities including CB, and HAM Radio almost my entire life, and I get so tired of the new Hams acting like they know everything, when most of them just memorized the answers. These hamsters squawk about everyone being off freq and tell them to buy a better radio instead of helping them fix the radio they have or using their clarifier. They also just parrot crap they read or hear from others and have never actually tried any of it. Then a few days ago I ran across a Hamster guys video where he is supposedly teaching other Hams how to use a MOT for tube filaments here: ua-cam.com/video/8o3ttyrXIeM/v-deo.html So, between these two issues, I made this video a little snarky with a small dig at a Hamster, and I wouldn't be surprised if the negative comments are from Hamsters, if not, they will be now LOL.

    • @KallePihlajasaari
      @KallePihlajasaari 2 місяці тому

      @@bigcbradio I used CB in my youth, had a Ham call in ZR6 land but have moved to OH2 land and have yet to rewrite the test here though I did a refresher course in the local vernacular with my son. Perhaps we should just book for a test and get local calls, they may come in handy one day if the internet censorship gets real bad and one cannot even connect to the net without a biometric ID and a certificate of vaccination.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@KallePihlajasaari I am not too worried about the internet or the end of the world, etc... But that being said, I do stay prepared to be self sufficient in the even of most disasters or if the shit would hit the fan. I own multiple properties, I have solar, batteries, water, water producing equipment, water wells, food, seed, and transceivers and antennas to listen/communicate on just about any frequency there is, and no I don't need a vax

  • @viermidebutura
    @viermidebutura 2 місяці тому +9

    Change the fkin battery on your smoke detector

    • @ScandalistRick
      @ScandalistRick 2 місяці тому +3

      Which believe it or not, IS RADIOACTIVE TOO!i!i!i!

    • @jeremiahbullfrog9288
      @jeremiahbullfrog9288 2 місяці тому

      HAHA i leave mine chirping just for guests like you

    • @bigcbradio
      @bigcbradio  2 місяці тому +4

      Na, it makes great conversation.

    • @LeoTiger12
      @LeoTiger12 2 місяці тому +2

      @@ScandalistRick Nerd time: the older ionization smoke detectors used americium-241 for detecting smoke, which is radioactive, but the newer ones just use light sensors.

    • @bigcbradio
      @bigcbradio  Місяць тому +1

      I borrowed a ladder from my neighbor and replaced the smoke detector battery.

  • @leroyolson4349
    @leroyolson4349 2 місяці тому +2

    Excellent presentation, I like hearing Expert's? quoting factual information. You did a bang up job, explaining the fact's for this type of Transformer. Thank you N8AGW.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      Thanks, I'm not an expert by any means, but some things I know because I've tried and learned the hard way many times. I actually learned about those primary windings from some old YT videos over 10 years ago, it was some kids in Thailand building toroidal transformers and explaining that as they added windings that the idle current kept going down. It was not in English, so I just kept watching what they were doing because they had a light bulb in series with the primary and as they added windings it kept getting dimmer. That sparked my curiosity so I started studying, and in that studying I ran across the descriptions of MOT's and how they cheat and short wind the primary, and the saturation, and all the other tricks.

    • @leroyolson4349
      @leroyolson4349 2 місяці тому +2

      @@bigcbradio Well you have a good understanding of winding transformers. Microwave transformers are a great means of transformer stock, easy to get apart, and remove, or add secondary windings. You are the first person to post the fact that the primary winding must be changed also. This is very important and thanks for pointing it out.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@leroyolson4349 You are very welcome.

  • @dieseldes6578
    @dieseldes6578 Місяць тому +1

    If you get 2 identical MOT's and series the primary's, each will only see half of the mains voltage, and run much more efficiently and cooler. The issue is, as you described, they have too many volts per turn on the primary. Then you can wind whatever you want on the two secondary's, but you need to balance the loads, so say you want 12v, wind the secondary the same on both and series them to get 12v.

    • @bigcbradio
      @bigcbradio  Місяць тому +1

      I actually have many mot's and I do have 2 matching. I was planning on doing just that with them, but I haven't got around to it yet. I was going to run the secondaries in parallel. You have good advice, hopefully others read this also.

    • @dieseldes6578
      @dieseldes6578 Місяць тому +1

      ​@@bigcbradioseries is better as it spreads the current evenly. Just aim for half the voltage required on each one.

    • @bigcbradio
      @bigcbradio  Місяць тому

      @@dieseldes6578 I will try it both ways, it is just for 6.5 volts so it will be easy to try it both ways. Maybe I will put them next to each other and try looping the secondary thru both ! 😀

  • @ScandalistRick
    @ScandalistRick 2 місяці тому +7

    Just a heads up, the most informational video with the most accurate information can be completely shrouded by demeanor.
    Curiosity is the only thing that barely kept me watching throughout your "I'm better than everyone and I'm an expert" attitude.
    If your goal is to actually spread useful information you should become more of an expert on presentation/people/communication... The thing that all of these people you talk shit about are good at.

    • @bigcbradio
      @bigcbradio  2 місяці тому +3

      Noted, but I will be the first one to tell you, I am not better than everybody and I am not an expert, that was a joke. If you see any of my videos I tend to use some dry humor. For example in one of my videos I have a half a dozen screw drivers sticking out of a radio and super glue, Elmer's glue, a knife, and a hammer close by, and I'm using Vice Grips as a heat sink. But in all seriousness, I am tired of seeing videos that people act like experts and they aren't, someone is going to have a fire using MOT's that sit there getting hotter and hotter. Once again I am no expert, and most of my videos are very neutral, no politics, no religion, no abuse, and I do allow anyone to post any comment they want, if I find it abusive, etc, I will leave the comment for a few days, then delete it, but at least everyone gets to see it for a while. And yes, just this once I really was fed up with all the MOT videos and I mentioned it. I guess if I get enough negativity because of it I will delete my video, but if someone can sit through my fit and learn something that's OK too.

    • @qdsmith
      @qdsmith 2 місяці тому +1

      FWIW I have no problem with the tone of this video. Some occasions require a subtle approach, others a swift kick upside the head - delivered with humor and sarcasm, of course. I've seen far too many YT "experts" state that stripping the secondary and rewinding without addressing primary current and dissipation is Just Fine. It ain't, kids. At best it's a recipe for equipment damage, at worst a life safety issue. Calling these good folk out may offend their delicate sensibilities, true. If it prevents a house fire I'm good with that.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@qdsmith """I've seen far too many YT "experts" state that stripping the secondary and rewinding without addressing primary current and dissipation is Just Fine. It ain't, kids. At best it's a recipe for equipment damage, at worst a life safety issue""" Isn't that what I said? Well.... maybe you said it better, and nicer. LOL

    • @ScandalistRick
      @ScandalistRick 2 місяці тому +2

      @@bigcbradio That makes total sense, I understand having more feelings towards something you are passionate about for sure. I would never call this video negative, and with your explanation I understand where you are coming from. I initially read you wrong.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@ScandalistRick yes, text messaging, message boards, blogs, posts, etc... it's hard to tell sometimes what a person is like. In person I can be quite the dick, and trust me I have my opinions, but I try to keep my videos pretty neutral. Most of my videos are CB radio related, and on the CB radio it seems to be one of the last places where people can talk to random people all over the country and the world and it doesn't matter who or what you are. Don't read that sentence wrong either LOL. I am very set in my old fashioned ways and about as far as I will go is to say I am not woke. LOL

  • @gregwmanning
    @gregwmanning 2 місяці тому +3

    Great video learnt something important Thanks

    • @bigcbradio
      @bigcbradio  2 місяці тому

      This primary info is a good place to start. Glad you like it. Thanks for the comment

  • @campbellmorrison8540
    @campbellmorrison8540 2 місяці тому +1

    Hum ok sounds very reasonable and explains why the microwave hums when its zapping the contents. I was considering using one for a spot welder but was given an old radio filament transformer for huge KW valves and its only a couple of volts with no hum and huge current and doesn't get even get warm. Mind you its heavy.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      Nice filament transformers are getting harder to find and usually expensive. I don't know what transformer you have, or what kind of spot welding you want to do, but most spot welding will require more amps than you would want to try to extract from a filament transformer. I would hide that filament transformer in my closet and find a free microwave transformer to turn into a spot welder. For use as a spot welder you wont need to add any turns to the MOT primary as long as you have it switched on and off with each spot weld. There are a lot of spot welder MOT videos on YT. Some are crude, some are pretty nice. Good Luck.

    • @campbellmorrison8540
      @campbellmorrison8540 2 місяці тому +1

      @@bigcbradio Yes I would agree but Im making only a micro spot welder primarily for tinplate, nichrome elements and maybe battery tab welding so although the MOT would suffice I thought that having this Xformer I may as well use it as I will never be doing anything with large valves.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      @@campbellmorrison8540 Sound good, have fun, and maybe make a video while you build it.

  • @clytle374
    @clytle374 Місяць тому

    I had to do a little research before posting and I'm not 100% sure on this, but think I've got a pretty good handle on the facts. If the transformer was running in magnetic saturation, add more turns would make it worse as that would increase the magnetic field. What would be fixed by adding turns is if the base inductance wasn't high enough for good reactance at line voltage. This is why you do see people ballast the transformers with caps or inductors to tame them down. Just lowering the voltage that's across the primary.

    • @bigcbradio
      @bigcbradio  Місяць тому

      Just like you I have done research over the years, and specifically on MOT's, and again like you, I'm not 100% sure on anything either, but I like to think that I also have a good handle on it. What I do know is that if you add windings you can reduce the idle draw to almost zero and add your own secondary to MOT's and use them without them getting hot when there is no load on the secondary. I also still believe that as they are wound from the factory they are saturated, that is how they limit the power to the tube. As far as ballasting, I personally think that it a very poor and incorrect solution.

  • @drewdo
    @drewdo 25 днів тому

    i mess with your videos dude, good stuff

  • @Felix-tz1tk
    @Felix-tz1tk 2 місяці тому +1

    amazing.. learned something new today.

    • @bigcbradio
      @bigcbradio  2 місяці тому

      Glad to hear it! Thanks for the comment

  • @UniCrafter
    @UniCrafter 2 місяці тому +3

    I tried to turn a MOT into an Isolation transformer and ran into high idle currents etc, ended up having to wind two primaries in series, luckily I had enough lying around to not have to wind my own. Disappointed to have a transformer twice the size but half the power, but helped explain why microwave transformers are so much smaller than other transformers I've got with similar power.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      yep, if you compare to any ideal transformer that delivers the same amount of power, they will be twice as big as an MOT, but MOT's can be wound to be efficient enough to be very useful

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      also, I didn't mention this in the video, and no one has mentioned it, but I had to use 5.5 wraps instead of 4 wraps on the secondary to get the same 4 volts after I added to the primary.

  • @whatevernamegoeshere3644
    @whatevernamegoeshere3644 2 місяці тому +1

    I never thought of that, that's awesome! Thank you!

    • @bigcbradio
      @bigcbradio  2 місяці тому

      You are welcome, there are a few more details in my text description just under the video.

  • @Pulverrostmannen
    @Pulverrostmannen 2 місяці тому +2

    I already knew this way before I watched this that these transformers are terrible for low power or continuous operation due to their saturated design. however, to just yolo it and adding more turns like you did here is not really a best cutting edge solution I would brag about either as it will not solve all downsides these transformers have. But hey who am I to know.
    A better solution would be to wind a completely new primary winding for it calculated for the lowest possible current draw under no load condition. a well made transformer should have barely any current draw at all when no load is applied to it, the issues with microwave trannies is that the sheets are welded together making the Eddie currents worse in the core so it simply can´t become a good transformer even if you re-wind it really good. I would simply just use these cores for simple work and keep it for such instead of being cheap and crappy. But I do admit that adjusting the primary side is more important than most people say.
    and for god sake if you know your smoke detector battery is flat just go replace it when you know you making a video with it in the background

    • @bigcbradio
      @bigcbradio  2 місяці тому

      Yes, adjusting the primary side is very important, and yes an ideal transformer will have almost no draw at all. If anyone here is trying to make an ideal transformer they should do some serious calculations, then go by a toroidal core and some new wire, but I don't think people hammering and / or cutting apart MOT's here on YT are trying to get that technical. Anyways, thanks for the comments and if you can, run over to Arizona and pick up my 20' ladder so I can reach my smoke detector, or bring me your ladder and a battery. Alternatively you can turn down the volume and use the closed caption feature😁.
      Since you said "A better solution would be to wind a completely new primary winding for it calculated for the lowest possible current draw under no load" aren't you kind of defeating the purpose of using the MOT to begin with? You might as well just tell YTubers to just go by a blank core and a bunch of wire and start over. You are defeating the whole purpose of repurposing the MOT to begin with.

    • @Pulverrostmannen
      @Pulverrostmannen 2 місяці тому +1

      I would happily change the battery for you if you would pay for the trip but I am on the other side of the planet so it is quite a bit of travel to do so I’m afraid

    • @bigcbradio
      @bigcbradio  2 місяці тому

      @@Pulverrostmannen LOL, OK

    • @bigcbradio
      @bigcbradio  2 місяці тому

      I borrowed a ladder from my neighbor today and put new batteries in all the high ones.... it's really boring around here now.

  • @zeno-alexei
    @zeno-alexei 2 місяці тому +5

    I THINK THAT YOUR STATEMENT... is actually true.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      the statement that I am not an expert ☹

    • @zeno-alexei
      @zeno-alexei 2 місяці тому +1

      @@bigcbradio that using a transformer incorrectly increasing the chance of your house burning down is... not good 😊

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@zeno-alexei LOL, cool, I dodged that bullet. Thanks

  • @Outlaw_Traffic_Stops
    @Outlaw_Traffic_Stops 2 місяці тому +1

    You should also probably mention, in passing, that the original secondary winding WILL KILL YOU !
    QUICK !
    DEAD !
    End of story .

  • @ebenwaterman5858
    @ebenwaterman5858 2 місяці тому +1

    Great vid. Explains a lot. Thanx. :)
    My MOT has a magnetic shunt between the primary and the secondary windings. What's up with that?

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      Thanks for watching, and yes, carefully get rid of the magnetic shunts. Its pretty easy to damage the primary windings.

    • @ebenwaterman5858
      @ebenwaterman5858 2 місяці тому +1

      @@bigcbradio That's what I thought, Thanks. :)

  • @billynomates920
    @billynomates920 2 місяці тому +1

    thanks for your video - the more you know, the more you know and now i know more. cheers.

    • @bigcbradio
      @bigcbradio  2 місяці тому

      You are welcome. I'm glad you liked it.

  • @williamlangley2044
    @williamlangley2044 2 місяці тому +1

    You can get magnet at the electric motor shop.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      yes, and on eBay and aliexpress

  • @roylarsen7417
    @roylarsen7417 2 місяці тому +1

    He can't change his battery in the fire watcher

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      I don't know which way the battery goes

    • @bigcbradio
      @bigcbradio  Місяць тому +2

      I borrowed a ladder from my neighbor and replaced the smoke detector battery. So boring around here now.

  • @hankosaurus
    @hankosaurus 2 місяці тому +2

    Reach down to those below you and pull them up as hard as you can. Reach up to those above you and push them up as hard as you can. Thanks for the useful information about the transformer windings. 73, kc4i

  • @MichaelOfRohan
    @MichaelOfRohan 2 місяці тому

    I never understood why we trash the secondary and keep the secondary? Shouldnt we be doing the opposite.

    • @bigcbradio
      @bigcbradio  2 місяці тому +2

      "trash the secondary and keep the secondary?" What did he say?

  • @sempertard
    @sempertard 2 місяці тому +1

    Very useful, thank you. So with 120 turns vs 80, the coupling is now better? I guess the microwave companies use the minimum amount of turns (copper), assuming full load, to save a few bucks? Is there a formula you used to determine the appropriate amount of turns for an iron core xformer running at 60hz?

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      Yes, 120 vs 80 much better, but you can "fine tune" the number of turns yourself and find the sweet spot (read my description). Then yes, they save more than a few bucks. They save on copper, they save on core size, they save on shipping weight, and they save on returns from blown up tubes because the transformer is self regulating the output power to the tube no matter what your mains voltage is (within reason). There definitely is a formula/calculations for building transformers. Very complicated if you ask me. There are some very basic calculators online, and then there are the real calculations that need all the info. For the real calculations you need to know what you are going to use it for, the supply voltage, the output voltage, the load, the frequency, the core size, the core type, how big your waist is, and what country your wire came from, how many kids you have, etc... But I am not an engineer, I'm just a you tube dummy, trying to help out with my 2 cents.

    • @sempertard
      @sempertard 2 місяці тому +2

      @@bigcbradio >>>transformer is self regulating

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@sempertard I have several old neon signs, but I have never needed to open one up, so I have no idea what the transformer is in there, but I will have to believe you.

    • @petruse8893
      @petruse8893 2 місяці тому

      @sempertard The manufacturers of microwave ovens don' save on copper. Copper was eliminated from MOTs many years ago, which boast 100% aluminum wire. The same goes for garbage disposers. Try to solder the "copper wire" in a MOT or simply look at the cross section of cut windings

    • @bigcbradio
      @bigcbradio  2 місяці тому

      @@petruse8893 I guess that is good info, good thing the half dozen or so I have are mostly 20 years old. Hopefully they are all copper. Regardless, the companies still save on cost and shipping weight.

  • @beakytwitch7905
    @beakytwitch7905 2 місяці тому

    The preloading is not because of too few windings in the primary. The welds that short the iron laminations together are inducing eddy currents, which preload the transformer. (Iron losses, not copper losses). If you were to use an angle grinder to carefully remove the welds, you will find that the transformer returns to normal and draws little or no energy.
    In the microwave oven you will find a second mains-powered transformer, a much smaller one, which supplies 12 Volt power to control circuitry and a relay which can power on the big transformer. So in use the big transformer is energised intermittently, not energised continuously. I hope that this helps. ❤😊

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      NO, Do not cut your welds people !! I do not agree with this! You DO need extra primary windings. The big transformer in a microwave is not "intermittently energized" "while in use" unless you have chosen the "low power" or "defrost" setting, which in reality is NOT low power, it is still full power (or as I call it, "wide open throttle" LOL) that is simply turned on and off every few seconds, and you can hear this happening while you use your microwave at home. Misinformation like this is Exactly why I made this video. It appears I am going to have to make another video about this...
      Additionally, since you mentioned "intermittently".... many people are wanting to rewind these MOT's to use them continuously. Cutting the welds is Not going to keep these from overheating in continuous use.

    • @ScandalistRick
      @ScandalistRick 2 місяці тому +1

      By intermittent are you talking about the on/off 60 times per second due to it having to be driven by AC power? Under that definition everything I plug into a wall is intermittent.
      As bigcb said, intermittent operation only occurs on the low power or defrost setting. Even then it is always run at full throttle, just shorter intervals.
      Also curious why you come here and recommend people start removing welds on a transformer; in the comments section of a video talking about people doing stupid things with transformers...

    • @bigcbradio
      @bigcbradio  2 місяці тому

      @@ScandalistRick that is so funny... LOL damn, everything is intermittent, you're cracking me up

    • @therealromster
      @therealromster 2 місяці тому +1

      @@bigcbradio It's called duty cycle. When you use the defrost low or medium settings. Yes it's either off or on the magnetron. The duty cycle averages out the heating and time for the heat in the food to spread out before the next on cycle. The issues is they save copper and make it saturate the magnetic field as it's only used for a short time and it has fan cooling in operation, also the magnetron is always pulling something like 700 watts continuous after a couple of seconds after it's heater is hot. So that transformer is under load most of the time it's on. Welding the lamentations just helps prevent buzzing and it wanting to rip itself apart from the strong magnetic fields. Typically a iron core transformer would use around ~3 turns per a volt.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@therealromster LOL, yes, I know what a duty cycle is. But regardless, I use laymen terms all the time, such as "wide open throttle". I am here for fun and helping hobbyist and not trying to have a class about flux, inrush current, power factors, ohms, impedance, inductance, henrys, or a class on turns per volt formulas.

  • @realvanman1
    @realvanman1 2 місяці тому +1

    Absolutely correct. I’ve been laughing about this for years. Kudos to you for making this nice PSA about it. I’ll add that the other reason these transformers are designed the way they are is because it is cheaper. It is all that’s necessary since they only operate on load except for the couple of seconds for the magnetron filament to heat. Notice a MW hums loudly for a couple seconds, then quiets down.

    • @bigcbradio
      @bigcbradio  2 місяці тому

      Me too, but enough was enough

  • @williamlangley2044
    @williamlangley2044 2 місяці тому +1

    0:24 Doesn't bombarding tritium with electrons emits X rays?

    • @bigcbradio
      @bigcbradio  2 місяці тому

      Maybe, I will let you know if I start glowing green like the Uranium Glass Tubes I have.

    • @anthonywilliams7052
      @anthonywilliams7052 2 місяці тому +1

      @@bigcbradio Just don't make him angry.... you wouldn't like him when he's angry! LOL...

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@anthonywilliams7052 HaHa, you are aging us now

    • @clytle374
      @clytle374 Місяць тому

      No, to get X-rays you want very high voltage electrons hitting something like tungsten in a hard vacuum.

  • @jeremiahbullfrog9288
    @jeremiahbullfrog9288 2 місяці тому +2

    You're still putting in 150 watts and getting out 20 watts though?

    • @ScandalistRick
      @ScandalistRick 2 місяці тому +3

      Much better than putting in 1200 watts and getting 20...

    • @jeremiahbullfrog9288
      @jeremiahbullfrog9288 2 місяці тому

      @@ScandalistRick yes but is it really "efficient"? I agree it's a vast improvement, there's still something wrong here... transformers can be 98% efficient, this is less than 15%. I also wonder about real vs apparent power (VA vs watts)

    • @r.e.m.s
      @r.e.m.s 2 місяці тому

      no, you cannot just multiply current and voltage to get the power, there is also the power factor to take into account if you want to calculate the real power.

    • @jeremiahbullfrog9288
      @jeremiahbullfrog9288 2 місяці тому

      @@r.e.m.s Yes i just pointed out the real vs apparent power which has been ignored in this presentation.. i can only go from the information in the video.

    • @r.e.m.s
      @r.e.m.s 2 місяці тому

      @@jeremiahbullfrog9288 Ah, I think I read your comment a bit too fast then. You're right VAR and Watt are two differents things.

  • @RobertMichaelPhotography
    @RobertMichaelPhotography 2 місяці тому

    Well if anyone has ever had a decent conversation with you, they would know your sarcasm. Good info. Maybe throw in a little ohms law for the future young nerds out there. With the same V as R goes up, I goes down. This also lowers P, but how many watts do you really need? 😊

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      who is Ohm and how did he achieve the power to make laws? Up n Down? Like this? VRip. I will leave the technical parts for you to make videos.

    • @RobertMichaelPhotography
      @RobertMichaelPhotography 2 місяці тому

      @@bigcbradio 🤣🤣🤣🤣🤣🤣

  • @vvorldnewsmedia
    @vvorldnewsmedia 2 місяці тому

    which was it wind in the first place?

    • @CG-rr6yx
      @CG-rr6yx 2 місяці тому +1

      I suggest reading attentively the description of the video and the replies of the author to some comments above. Every bit of information is there for everyone to understand, even better and faster than watching the video .

    • @bigcbradio
      @bigcbradio  2 місяці тому

      @@CG-rr6yx Thanks for that, I keep repeating myself. Maybe I will make a shorter my specific video soon. I was being a little pissy in this video.. LOL

  • @AverageJoe2020
    @AverageJoe2020 2 місяці тому

    'Magnet wire' is not a thing- you mean 'Enamelled copper wire'. The iron in those transformers is welded together and that is crap as regards transformer design- all the leaves should be isolated from each other, MWT's are built cheaply to provide short bursts of HV and that is all.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      next you will tell me "wide open throttle" is not a thing HaHaHa. Short bursts? I will make sure not to cook my pizza longer than a few bursts then. I would also bet the farm that you have never actually tried using a MOT for any project before because obviously you do not know what you are talking about.

    • @bigcbradio
      @bigcbradio  2 місяці тому

      Also.... en.wikipedia.org/wiki/Magnet_wire

  • @mutzbunny
    @mutzbunny 2 місяці тому +2

    I think you should re-record this video and reupload it.
    while your information in this video seems quite valid and accurate, your constant bragging about how much expert you are makes many people mad. including me. where is your university certificate to call yourself an expert. yes you kinda know what you did, but who cares about how expert you are. just give us the information we need, and leave out all the complete bullshit you are talking about.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      I appreciate your view but if you read my description or my other responses you will see that I explicitly say I am not a transformer expert. It was meant to be funny. I already love the comments, good and bad. I will not be deleting this video. Regarding a certificate, I am the one companies call to fix the problems the people with certificates cause or are unable to fix.... and that is not meant to be funny, that is a fact.

    • @mutzbunny
      @mutzbunny 2 місяці тому +1

      @@bigcbradio i did read the description and i understood that you are not a absolute jerk trying to flex themselves. But the fact that its supposed to be funny just isnt. Its more annoying and distracting than funny.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@mutzbunny sorry, I guess I will learn from this. I have about 350 videos over the last few years and this is really the first one to cause a ruckus.

    • @mutzbunny
      @mutzbunny 2 місяці тому +1

      @@bigcbradio i have watched many of your videos and mostly enjoyed it. I learned a lot. So i understand that you might want to Change up your content and try out stuff.

    • @bigcbradio
      @bigcbradio  2 місяці тому +1

      @@mutzbunny No, actually my future videos will be more like the older ones. I usually make sure my videos are pretty neutral, no religion, no politics, no bs. If some one leaves shitty comments, I do not pre-screen the comments and I do leave their comments for a couple days for people to see, but I do eventually delete them. Even when I am recording radio chatter, I do not post negativity from the radio, and there is a lot of that on the CB.

  • @noslidemais
    @noslidemais 2 місяці тому +2