Microwave Oven Transformers Using Them For Projects

[Music] hi so these things microwave oven transformers really amazingly useful you can do a ton of good stuff with them and the dead easy to get hold of from scrap microwaves so amazingly useful gets a kit with two problems with it one is how do you know how much wire to put in there and what kind of wire once you've got this bit out and the other one is how do you get that video now I've done quite a few of these and have tried loads of different methods to actually try and get that out including methods like cutting down that weld seam I've cut down that weld seam with a hacksaw and with an angle grinder prised it off tried to join it back together and to be honest it's a bit of a nightmare because even when you've got that off lifting that out is a challenge then I've tried things like cuttin this off and whacking a bolt through it that was really hard work but in the end what I came up with was cutting both of these signs off drawing it out with a drill bit somewhere about eight to ten mil and then instead of using a bolt or a chisel which basically spreads those wires and locks everything in place what I've been using is this it's a stripper steel it's three millimeters thick one centimeter across flat ended and that works really well takes about five minutes to get those out it's astonishing anyway what we're gonna do is just demonstrate that and take that out okay it's in the vise it's much easier to cut a vice that pretty heavy so you can do it you don't have a vise and get your hack so make sure you pled isn't too blunt and in-between this bit here just the second R incidently and it's the one with the thin wires that's pretty much universally the one you want to remove this one's the primary where the thick was but between those two is quite a gap actually that gap is made out of some shims that are put in there and then this loves voltage coil that runs between those two primary and secondary coil well that means is we could saw it down going at it but then when we get nearer to there you just take a little bit more time and cut it out carefully and the whole thing will come out really well it comes away pretty clean and that last little bit saw carefully and it'll come away like that okay now we need to drill that out okay I've got it on some flops it's a taint little bit and was thinking of a larger one this is actually quite a small transformer eight mil ago nice through that and you don't want to hit those sides and then bet you just drilled both of those all the way through the vise drilled all the way through and I'm going to walk through with my bar now I think the reason it's so difficult with the chisels and bolts and other bits that people have been using is because these wires are packed in here really tightly and what you'll need to is give them a little bit of room so that they can spring out and they'll just push out so the first little bit is a bit difficult in there takes a few whacks and it comes out nice and clean okay so here it is all cleaned up now that was so easy I did a big one there's a really big one as well now though it's use these things it's all to do with the ratio of turns in the coil so ever have a look at this one this one's one I haven't done yet and it's got two columns in it this lower coil which is thick wire not so much of it is the primary this upper one which is thin wire there's absolutely tons of it is a secondary this one that steps the voltage up because it's got to run a magnetron that needs about two kilovolts or so but its supply is from the UK supplied to 230 volts round about 200 volts and it needs to step it up about ten tons in order to do that there are ten times more turns in here than there are in here so in this primary let's say as 200 turns the secondary will have 2,000 turns so then we get that voltage step on now the voltage step-up isn't the only thing that happens the reverse happens with the amps so if I feed why in here what will happen with this it'll be point one of an amp that's drawn from here now what happens is we're using an AC current so we put a current in there and that creates a magnetic field in this block when the current falls back down again it effectively switches off that magnetic field collapses and pushes the current through here at the voltage that is related to the number of turns now we don't want to get step-up transformers like here we're stepping up the voltage we can get step-down transformers okay to demonstrate that what I've got here is one of the Transformers and I put a single turn of this red wire through this red wires just jumper cable wire I've attached it to my voltmeter I'm getting a volt reading at the moment and the other side here I have attached to the live and neutral of a plug and I'm just gonna plug it in I've also put a momentary switch in so that when I plug it in it doesn't turn off I turn on so they have to get to the plug I can just press that switch and we're gonna read the voltage so put one turn on that and if we plug that in and read that voltage we get point nine in the vault so that's not going to do much for me but remember this is a UK version point none of the vaults if we rewire that and we put an attorney and now we get to point two volts so the voltage is going up because there's more turns which means that ratio is going down okay so to have a look about effect I've bolted on two locking pliers unto a single turn in my transformer and I've put a stainless steel nail between them and if I start that you can see it starting to get hot but it took quite a long time now let's put two turns on okay so I've read it I've now put an extra turn on that transformer and if we hit that power it starts to smoke and this time we can get it really hot oh I wasn't expecting that okay so that's basically what spot welder is actually so if you've actually tried to make a spot welding you've put on the one turn that everybody talks about and it's not working well put another turn on it's only to do with the way you can't transform a came from but that gets has hot enough to weld stuff all you've really need is exactly what you see here that is something to plug it in and power transformer a suitable cable and then two points that you can actually leave her up and down to touch and spot weld or equally we could do it like that that is your spot welder and then a moment to switch somewhere convenient so you have control over it but I thought I would share that with you I hope it was of interest and thank you very much for watching

Channel: Robert Murray-Smith

Views: 130,977

Keywords: robert, fwg, microwave oven tranformers, spot welder, transformer, spot, welder, welding, home, made, make, build, built, recycle, lab, workshop, equipment, recycling, upcycling, electricity, electronics, murray-smith, how to, engineering, electrical

Id: uw3jmW1I4oU

Length: 7min 38sec (458 seconds)

Published: Wed May 27 2020