DIY spot welder with foot pedal

Homemade spot welder with foot pedal. Detailed instructions on how to build one.
DISCLAIMER:
The spot welder presented in this video uses mains voltage (110 - 240 V~). Always be careful when using this as a source for your DIY devices, the voltage/current involved is dangerous and potentially lethal if misapplied.
I'm not a trained electrician. This video is for entertainment purposes only. If you inted to replicate what you see, do it at your own risk.
This device is made for home use only. It does not cope with a 100% duty cycle and needs cooling after a few spot welds. Please bear that in mind when building/using your own.
Music taken from the KZbin audio library:
Cool Rock - Take the Lead by Kevin MacLeod is licensed under a Creative Commons Attribution license (creativecommon...)
Source: incompetech.com...
Artist: incompetech.com/
Bicycle - Reunited by Kevin MacLeod is licensed under a Creative Commons Attribution license (creativecommon...)
Source: incompetech.com...
Artist: incompetech.com/

[@sreekumarUSA]

Greetings from California. Yes, it was nice watching your Spot Welder assembly. I’d suggest that you modify the mains switching through a SSR, thus avoiding a surge and or spike or spark at the foot switch. I have often seen the direct foot switch activation to 110~220 mains the above happens and the micro switch fails. Also it’s unwise to have 220Vac (in your case) running along towards the FS. By introducing SSR you will be able to avoid above issue by activating SSR through 3~12Vdc. Also install a 20AMP fast blow fuse. This will avoid your ELCB (in the mains circuit) from tripping often. The secondary cable may be made to fit as tight as possible in the core avoiding fluctuation while spot welding. Remember when spot welding, loose secondary cable tend to vibrate or pulse; thus causing issues in weld result. Good Carpentry work. Cheers.

[@josephbrianwilliams6532]

Brilliant work...im not sure what the negativity is all about ...Your explanatory , workmanship and diagrams is exquisitely presented...This surely has to be the best presented welder on YT...well done

[@coolbionicle]

This is an awesome build! A good idea is to replace the pedal circuit with a mono-stable 555 timer circuit (with a low power pedal) controlling a relay so as to separate any contact with the mains circuit. Another idea to save power would be to buy two cheap 1 amp phone chargers to act as buck converters to replace the high power light bulbs with LED's and the one that powers the green LED could be used to power the proposed pedal circuit.

[@timmax4817]

Wow what a professional job! Including a great schematic! Im SURE no one else bothered or ..would know how to make a schematic, and GREAT ENCLOSURE, OVERALL excellent!

[@Waltkat]

Very nice tutorial, but I have a couple of suggestions. You have an opening for cooling air to enter, but where does it exit? Add another hole and meshed screen over the transformer to allow air flow. For added safety, instead of using a foot pedal with mains power going through it, add a small 12 volt relay and use the the foot pedal to switch the 12 volt on and off to the relay which will then switch on the mains power to the transformer. A automotive relay can be used because their contacts are rated for a 30A load. You can get the 12 volts by adding an additional secondary winding to the transformer using some small gauge wire such as 22-24AWG since the relay will not draw very much power. Thanks again for showing us your ideas.

[@diecksl]

Hi Waltkat, I did some changes to the device in the meantime, for example I drilled a 2nd hole for the air as you suggested. The idea with the automotive relay is good (adds safety), but I doubt it will withstand the welding current of the secondary. I ordered a SSR (solid state relay / TRIAC) to enable/disable the primary side. This has the advantage (depending on the SSR model) that it enables at the AC zero point, putting less initial load on the mains and fuses.

[@benitezgalvezantonio3323]

Perfectly well explained and especially thanks for the wiring diagram.

[@joop2295]

Excellent video on how to build a simple spot welder! Of course it is possible to add extra features, such as electronic control of current and timing.

[@byronskikersakov3512]

Nice work Lejf. A couple of minor mods for you to consider are to install some breather holes so the cooling fan doesn't cavitate and perhaps some rubber feet so the fan fixing ties can't wear. Cheers.

[@zapszapper9105]

Ground the fan grill. Cos exposed conductive part.Use with an RCD / earth leakage ( for personal protection) breaker, protected power supply..

[@yvon501]

Bonjour ! je suis très satisfait de cette vidéo qui ,malgré que je ne comprends pas beaucoup la "langue" n'en est pas moins explicative! Merci beaucoup! Thanks!

[@prasannakumar8832]

Perfectly made spot welding machine ,I used 16 mm wire 3 rounds for lifepo4 battery pack.but it was not sticking enough.sugestion please.

[@tronixfix]

You must be from germany! First person on youtube if seen putting an ground wire on metal parts for security reasons! Thanks for the video!

[@diecksl]

Correct, german. Dankeschön!

[@MarkSchuster-ym3iy]

Share the joke with the untermension !

[@gergc4871]

I trusted this guy immediately with the German accent.

[@diecksl]

What accent? ;-)

[@TheDIMONART]

I think, you from Denmark or the Netherlands:-)

[@maartenscheepmaker2407]

Dima Balan: definitly ont à Dutchman!

[@TheDIMONART]

Netherlandia county?:-)

[@maartenscheepmaker2407]

A Dutchman comes from Holland (capital Amsterdam, tulips, cheese, technolohy). They have a different accent out there.

[@spbygga8123]

Neat build and very clear instructions. Great!

[@chotuusian4127]

Good work

[@schrockie1]

Hey Lejf, I cleaned out my microwave transformer yesterday, cut wood today and started assembly. I was reading the conservation between you and Alpha Troniks and have a couple questions as I'm going to use mine for 18650 battery welding as well. 1) I didn't notice that you removed the metal tabs between the 2 coils, so mine are still there. I saw in one of your replies that leaving them in will reduce amps, so should I leave them there? 2) Would a basic dimmer switch for household lights work in this setup to further reduction of amps? If so would I install that switch between the power coming in and the transformer? I got my foot pedal from a Chinese spot welder that died after using it for a couple weeks (Sukko) and I believe that it's a momentary switch. If not I'll just pick one up on ebay and make a homemade you like you did. Sorry for all the questions! I'm no electrician but am very mechanically inclined.

[@diecksl]

Hello schrockie, 1) In the orginal application the tab (or "shunt") is used to limit the current flow. You don't want it, as you want to increase the amps. The shunt changes the magnetic flux path within the core - for example, see goo.gl/GC5ck4 . You should, however, separate primary and secondary with a piece of wood or plastic from each other to increase isolation for your own safety (don't forget to ground the iron core as well). 2) Dimmer switches are usually driven by TRIACs, they change the sinusodial waveform of the AC line voltage and not the (peak) voltage itself. There are two different types, phase control (PC) and reverse phase control (RPC). Only the first method is suitable for inductive loads like a transformer. You have to watch the temperature of the windings carefully - it increases when using a dimmer as it puts DC load onto the transformer. But for short welding pulses it should work. One word about welding tabs to 18650s: I had a long conversation with AlphaTroniks on that topic. Problem is, the heat increases far too slow. For metal welding this is ok, but for Li-Ion batteries this can lead to fire or explosion of the cells. What you need for that task is something that instantly releases energy (heat), this is why all commercial tab welders utilize capacitor banks.

[@edpontiff8448]

Good build , the back ground music was distracting and not needed .

[@piotrleszczynski5744]

Awesome design. Three things I want to add. The fan should work all the time, not only when you push the pedal, and also you should stronger attach those cables to the wooden elements. Also the welding electrodes should be thicker.

[@diecksl]

Hi Piotr, the fan works all the time if I remember correctly (see diagram in video). Still not enough cooling for long welds, as the MOT itself gets saturated quickly due to its small core size. About the electrodes: You're right of course, at the time I had no professional electrodes, only thick copper wire.

[@alphameric3786]

brilliant. and admire your safety advise. grounding in the equipment is very important.

[@diecksl]

Ground your devices or they ground you...

[@rahmanocawni5618]

Hi friend. You do a good job. It you have a time make a video of wilding lithium battery. We need the time pulse an the voltage.

[@diecksl]

This circuit produces a low-voltage pulse and heats the metal. For welding battery cells you want the pulse as short as possible to keep the temperature inside the batteries low (explosion/fire hazard). That is why usually capacitor discharge is used in this application.

[@SkypowerwithKarl]

Your air flow exchange is lacking a bit. Inlet and no outlet but circulates the same air well. Cut an air slot in the bottom between the transformer and the front cover. On mine, I measured over 400 amps but my meter only goes that far. The screen said something I’ve never seen before “O.L.” 😆. Mains measured 5 amps running and 12 amps secondaries shorted with 120v primary. There’s an enormous back emf (off my scale) when the mains are disconnected, So be careful it could bite.

[@ziadfawzi]

Nice work. Thank you.

[@istvanfrank9201]

Szép munka jó elmagyarázás. Tetszik.

[@letsthinking6266]

I like this one

[@JamesThompson-xl4yu]

Although this works, everyone wires the secondary wrong. Best is to use small gauge wire like 14 gauge stranded of multiple wires to fill the full cavity with wire that is grouped as parallel and total of 1 to 2 turns. IE 20 parallel wires together and long enough for 2 turns. The idea is to not leave spaces in the secondary cavity so all magnetic flux is coupled from the primary. Hope this helps others.

[@diecksl]

Makes sense to me. And is also cheaper then buying this AWG 5 wire (if I remember correctly)

[@AbdulWahab-vz5fq]

Good job.👍👍...

[@gortnewton4765]

Are you nuts!!! You've wired the live line (230 VAC) down to the foot pedal. INSTEAD, use a relay which you can run from 6 volts or 12 volts inside the box and run the, say 12 volts down to the foot pedal and back to operate the relay. The relay then uses 230 VAC to switch the mains to the transformer... MUCH safer.

[@omarcusihuaman4261]

How to reduce current peaks every time you activate the pedal? anyone?

[@vikkyrk239]

Bhai homemed welding machine ke liye kon sa tirancformer chahiye

[@muratkaraagac6014]

how many meters of the safe

[@Wuety06]

I used 6 series Maxwell 350f super caps ..2 sets in parallel. Adding a 3rd soon to try copper tabs. Used cad to design fet switch board...plexi to make cupric etch tank. plexi, eBay vac pump, digikey 365nm led, weather stripping and a sheet of low iron glass for exposing riston... inkjet screen printing transparencies with am emulsion to take ink well. Managed to etch double sided 2oz with a few 8mil (imp)traces mostly 10 and up. Geting brand name riston was the biggest factor in ability to etch features that small...i tried 2 others first and even with extensive pre prep results were shit bellow 10mil and only okish at 10. Board has isolation for mcu. Iso I2c for bleed resistor and I and e measure...also it has a p fet for optionally leaving 30a charger connected or disconnecting it during weld. 6 large fets switch the low side of weld path . 2 of them alone would handle it with their pulse rating but I didn't want huge heatsinks or to be shit out of luck if I added caps to bank

[@diecksl]

Do you have a video from your build? What voltage are the caps? 350f sounds like a LOT of capacitance!

[@Wuety06]

Lejf Diecks series =(single cap value/cap count)*parallel groups. So around 100f in my config. I will try to get a video up soon. I had a mold issue force me to change flats so everything is spread between 2 places and I haven't had a chance to finish plexi enclosure yet. I put the little time I had in the last few months into building a rig similar to a drill press but with a linear rail and 2 copper bar electrode holders with hex screws to put pressure on copper aluminum oxide alloy electrodes I ordered. I figure this will allow more constant quality in welding because it removes the b.s. of holding the electrodes free hand. I may add a spot to put some sort of 10 gram sized weights on it to allow pressure control...if not an electric or pneumatic actuator. I'll post a Google drive link if u want to see it. In not proud of solder quality or top coat on board. Keep in mind I was trying to figure out wtf was seemingly biting me while doing most of the construction lol

[@Wuety06]

Lejf Diecks drive.google.com/folderview?id=18HPdiKL6VqISkJ3b5HjDJeLEoROpb73r few projects mixef in this folder. I've yet to test weld stand and probably hit the foot switch 30times max. Far from dialed in..also intend to add lcd but at the moment I just use serial read to respond to single keyboard presses when a jumper is pulled (switch flip eventually) allowing me to inc or dec by 1 or 10ms depending on press

[@Wuety06]

Lejf Diecks caps max at 2.7v..hence the 6 in series, night add 2 more and or switch the extra 4 in and out with fets if I decide to attempt pulse /tig mode ...argon gas inonizes at 16v if i recall correctly currently the bank maxes at 16 so that wouldn't be ideal...but that's a long way off

[@Wuety06]

Lejf Diecks I haven't optimized or even measured r value but the math for just the esr ideal world means that at 16v it should deliver 1400amps (I think..been a while since I ran that...math)

[@abdulmajidmahvy2909]

NICE & WELL EXPLAINED, THANKS!

[@sajgonernest8041]

a jaka grubosc kabla zastosowales 25mm2 czy 35mm2

[@T2D.SteveArcs]

Cool nice vid mate

[@rubel5134]

Its good.but out put 2 or 3 v.how much input v.

[@mrtechnophile3483]

rubel ahsan I think it's 220V there. Either way, if you get a microwave oven that work(ed) for the local mains voltage, the primary coil will be correct. The secondary windings will be the same regardless: 3 turns.

[@radmansa5514]

Good work, thanks for sharing, clear and precise instructions with safety in mind!

[@giuseppevillella9445]

Complimenti per il progetto 👍😁🤝🔋

[@diecksl]

Grazie! 😁

[@anttivento8721]

great project! I think you should connect PE to the switch because there are some visible metal parts. just in case.

[@diecksl]

Thanks :-) Yes, it would not hurt. Since I published the video I did some improvements on the device. I will publish a second part soon and I will mention that...

[@PavelK77]

Very good job!!!

[@yumargonzalez2116]

Que numero de calle lleva

[@donfazio6884]

Greetings from Perth Australia, I really enjoyed your video, great explanations and diagrams, I have built one very similar, just wanted to ask, does your transformer get very hot and how can you avoid this ? Thanks again for a great tutorial.

[@diecksl]

Yes it does. This is due to the use of the MOT. A regular welding transformer easily has four times the size, dissipating the heat much better (and even these transformers have a thermal fuse which trips regularly, very annoying). You can try to improve cooling with cooling fins and a larger fan. Or pause aftera few welds. I added a cheap digital thermometer to the setup later to monitor temperature of the MOT core.

[@johnruscigno5738]

I put a large heat seek on mine in combination with the fan and it still gets warm but doesn't get too hot like before.

[@donfazio6884]

@@johnruscigno5738 Hi, I did the same but also included a solid state relay that switches the transformer on and off via the foot pedal, but allows the fan to keep running, this has helped a great deal with the heat issue as it doesn't run the transformer continuously.

[@soroka6983]

average house microwave oven transformer that raided at 750 watts only has a 375Watt-transformer core. If you only use microwave for a minute or so it’s no problem, it has a build in current limiter in the form of steel shims between primary and secondary winding, plus it has a thermistor that is opening up after microwave transformer core has reach certain temperature, usually set at 75 Celsius. Cooling transformer core helps. In my experiments the best wire is 4 AWG sorry do not know what is metric size, the volt is to be between 3 and 4 volt current from 50Amp to 70 Amp.

[@diecksl]

soroka69 True, a standard MOT core can't handle such loads for long (e. g. I measured my welder at 1500 - 1800 watts - remember its short-circuit load!). However, with a low duty cycle it works ok, but you always have to keep the limits of the device in mind. I stop welding as soon as I feel the cable gets too hot. But a temperature controlled switch is a nice feature to add, no doubt!

[@schrockie1]

Nice work! I'll use some of your ideas as I'm putting mine together.

[@diecksl]

schrockie1 Do that and share new ideas!

[@tsenam9392]

schrockie1 ಓದ್ಯೆರ್ ರೋಗ ಓಮ ಭೊಕ್ಕ

[@pawankimarpawankumar8239]

so nice education thanking you

[@AlphaTroniks]

welding is fun.. I totally agree... I am building the same welder for welding nickel tabs to 18650 cells... I tested the output voltage and it showed 1.5 volts... when I short the output the voltage comes to 0.8 volts. what is the ideal voltage for battery tab welding? The first I want to try out is to make a 3 cell pack for my 12 Volt cordless drill just to test out the welder. Here we get 3 cell 2200mAh pack for 800 Indian Rupees which is bit expensive.. I'm tired searching the net to find the answer for the correct voltage required for battery tab spot welding...

[@diecksl]

AlphaTroniks I don't know what the right voltage for battery welding is. But I am confident that you can weld your cells with 0,8 - 1,5 volt, as the high current is responsible for the heat and not the voltage in the first place. Your main problem is to limit the welding process to fractions of a second (1/8 - 1/4 second) as the welder generates a lot of heat, even in 1 - 2 secs. And this will probably destroy the cells. There are some people modifying spot welders with timers (e. g. with the NE555 IC) or building mini spot welders especially for battery welding, powered by MOSFETs and capacitors. Another simple way to connect battery cells is to use some flux and a soldering iron, but I guess you want to build a welder for the fun of it (like I did)?

[@AlphaTroniks]

I am building a spot welder for serious battery fabrication works... I have a timer using NE555 timer but it's problem is that at the lowest time setting the relay stays on as long as I am pressing the trigger switch but as soon as I increase the pot setting the time increases more than required i.e. it gives a pulse of more than 0.5 to 1 second which , I know is very bad for the 18650 cells... I need someone who'll help me with a proper 555 timer schematic

[@diecksl]

Do you have a link to the schematic and parts used?

[@AlphaTroniks]

no... I got the 555 timer board from a friend's company... I don't think they'll disclose the schematic... I will try designing my own using 555 timer... If you can help me that'll be great! my mail id is [e-mail]...

[@sreekumarUSA]

Bhai, the suitable volt at the secondary terminal is any thing in between 2.5 ~ 2.7Vac. Remember, you may not be able to test the Amps. It’s presumed to be between 400~800 amps. Ideally a tight 3 rounds of welding cable is recommended. That will provide the above mentioned Voltage parameters. Any thing above will, certainly will burn Ni strips and may also injure 186650. So be careful at obtaining not more than 2.5 ~2.7 Vac. Here we are talking about Spot Welder, only. Your requirement powering a portable Drill and suitable Li-Ion Cell Power Pack is different to the subject altogether. To get info, first of all, you need to specify the Operating Power Supply ie: 6,9,12,18, 20 volts on the basis of that, you configure the Li-Ion Cells. Remember it’s easy to assemble these Cells, you also must consider BMS to charge those 18650. This is a very long subject to describe here. All the best. Namaste🙏🏽

[@ymedhedi7296]

thank you very much for the video a small remark myself I did the same work as yours a small problem the big line of welding gets warmer what should I do thank you

[@diecksl]

ymed hedi Two ideas come to my mind: First, its normal that the secondary cable gets warm quick. It carries 400 - 600 amps! Thats why you should add a fan or make pause between welds. Second, the part within the secondary circuit with the highest resistance heats up the most. Make sure you use copper cable and copper electrodes (copper = low ohm resistance material). Thats why usually the metal between the electrodes heats up the most - it has a higher resistance than the other parts within the secondary circuit...

[@ymedhedi7296]

thanks a lot for your help i have a small problem if you allow I built the same I want to use for pudding to stick pucks on the body of the car to repair it the length of each cable is 1m 35 centimeters the problem is that there is spark. the pucks heat up but they do not stick on the tolle . thr intrnsity is 800 amp I thought I was using a starter solenoid 12 volts but I need the complete electric shema can you please help me

[@nandlalchoudhary2579]

sir you are my inspiration following your steps i also made just have to test but need your advice what is the input current you are providing (input voltage 220v). what is the input current?? please reply as i cannot move ahead without knowing as it may be very harmful.please help sir.

[@diecksl]

Hello Nandlal, the input current depends on various factors (wire size, transformer type, output voltage etc.). With this setup its around 10 - 12 amps @ 230 v (input). The output current is > 100 amps (don't know exactly as my meter maxed out). Remember, its basically a shortcut so the transformer takes what it can get.

[@nandlalchoudhary2579]

Thank you sir for helping me out can I melt iron metal if the two terminal are connected to the iron piece?? please sir tell as I want to try today thank-you sir and keep making such great videos

[@suniame]

Superb video I was searching for proper construction method from long time. If you could tell me how to do spot welding to a motorcycle gas tank to use slide hammer and pull/remove dents out it will be great

[@diecksl]

Sudarshan Bhat Interesting question. I just went upstairs and connected a piece of sheet metal to one side and a thin piece of copper wire (and also iron wire) to the other side of the output. I won't stick together. What about brazing some metal pieces using silver solder onto the dents and then pulling them out? Silver solder gives a pretty strong connection (soldering my sawblades this way) and you can remove the solder completely afterwards with heat.

[@diecksl]

Sudarshan Bhat You can also solder small holes in your tank and/or patches with silver solder. Just thinking..

[@AlphaTroniks]

finally I made it! and it worked!😁

[@alexstone691]

I am suprised you dont have a switch for the whole unit

[@AIexanderHartdegen]

Hi sir, nice made but just one thing When you made a new wiring, you must keep the wire as near as possible to the metallic core. Air gap between copper and the magnetic core is a bad thing for the effeciency and increase the equivalent intern resistor. A new wiring must be as tight as possible. And in the same time you save copper. Good continuation.

[@diecksl]

Alexander Hartdegen Thanks for the advice. I did'nt know that. As mentioned in the other comment, I will make a follow up with the changes and include that tip!

[@AIexanderHartdegen]

Ok that's nice.. Great day sir.

[@AlphaTroniks]

how are you bro! long time no see

[@byronskikersakov3512]

Oops, sorry guys. Should have scrolled down before posting.

[@MrLamojio]

Well done

[@kennyfication88]

Nettes Video, gut gemacht! Ich plane gerade auch so etwas zu bauen, allerdings mit Microcontrollersteuerung. Somit kann ich ein gekauftes Pedal nutzen, welches ich mit 5V DC oder so steuere. Pulsdauer usw. soll auch einstellbar sein. Ich brauch das tatsächlich zum Bauen von Batterie Packs, weil die günstigen China Batterieschweißgeräte durch dickeres Hiluminband nicht durchkommen.

[@diecksl]

Hallo kennyfication, lies mal die Kommentare zu diesem Video,über das Thema haben wir schon diskutiert. Die Power reicht zwar, sie muss aber "schlagartig" aufgebaut werden. Eine Kondensatorbank wäre da m. E. besser geeignet, ansonsten erhitzt du die Batteriezellen zu stark.

[@faidularcs]

👏👏👏👏 nice job

[@salahoua1]

Concerning the secondary coil you made, how do you know the direction of the wires should go around?

[@diecksl]

salah ouali Hi, Salah, I did'nt know. Just tried and it worked. Since its AC, it should not make a difference because the current changes direction 50 times a second (I think)?

[@valveman12]

Direction does not matter. It's AC.

[@kamzay01]

Instructives pour tout bricoleur

[@davids381]

nice one thanks!

[@DavidLopez-bz4rj]

Hello, I have a fan motor like yours from a microwave oven, i guess it is an induction motor? I connected it to main 220v and it spins but in a few seconds it begins to make some smoke from the winding. Do I have to connect it with a resistor? Thanks in advance

[@diecksl]

Usually these motors have their rated voltage printed somewhere on them. In most cases they are rated with the standard voltage of your outlet (230 or 110 volts). I have seen some cases (Galanz brand) with 21 volt AC motors. Since your motor spins, its obviously AC, but it seems to use a lower voltage. Try: 1) Use a variac (if available) and slowly turn up the voltage 2) If you don't have a variac, try to make an extra secondary winding with approx. 21 volts and see if it works (do one winding,measure voltage, divide 21 by that number = number of turns needed for 21 volts)

[@diecksl]

Btw, a resistor also may work. But dropping mains voltage to the voltage of the motor (21 volts or so) needs some beefy resistor since with a 5 Watt motor connected it will produce a considerable amount of heat (thats why a transformer is used in such cases)

[@DavidLopez-bz4rj]

@@diecksl Thank, I thinks its a Galanz rated at 220v, it surprised me when it began to smoke, it has 3 pins for fast-on connections, but Ican only see 2 of them with thin wire, I will test it with a multimeter, thanks, I wlill tell you if it finally burns!

[@DavidLopez-bz4rj]

@@diecksl yes, not a efficient way to do it. Maybe I will connect it to a variac. Thanks.

[@brahmareeddychalla4997]

Nice

[@user-xi1dh8gi4o]

Молодец ! С меня лайк.

[@supersilve]

Good job good explanation well done

[@diecksl]

Silvio De Leonardo Thank you!

[@ricardoguillen1204]

Español

[@ideafromkurdistan5257]

Thanks im can use eny transformer mecrowave , if small csn ?

[@hamidkeshvaripour2380]

only microwave transformer!

[@piait.yunususkywatcher2977]

Very safe

[@vijuav2172]

good

[@nigaflowmendoza2998]

Perfecto

[@redengineer1511]

Nice video! How can I recognize neutral and live terminal of the transform primary core?

[@diecksl]

It does not matter. In my country I can even turn around the plug by 180 degrees and change live/neutral.

[@redengineer1511]

@@diecksl thank you for respond me quickly

[@nadeemuk6194]

Hi are connect any ac with red wire at jut round in transformer

[@diecksl]

At which time in the video do you mean?

[@Daaremikkel]

I would probably use a relay and another small transformer to switch the welding transformer, thus avoiding mains on the foot pedal.

[@diecksl]

When I built that device, the idea was "as simple as possible". I agree a relay is a better solution (somebody mentioned it in the comments below somewhere). In fact I would go for a solid state relay (SSR) on the primary instead of a mechanical one. A SSR is a bit more expensive, but you do not have the problem of arcing when doing high-amperage switching like in welding which puts a lot of stress on a mechanical relay.

[@pingvinac]

@@diecksl add a timer circuit for "spot welding" , not spot melting ;) also it would work better with thicker wire in transformer and one less turn. besides that, i gave you a like for simplicity of design :)

[@peegat]

Minimum requiment VA for transformer?

[@diecksl]

A 700 VA microwave transfomer (MOT) will do. Keep in mind that a MOT is not a real welding transformer so its always underrated and needs cooling time after a few welds. If you want continuous operation, buy a real spot welder

[@scottparker1220]

On 220 volt both lines are line voltage of 110 each combined equaled 220. Where 110 volt you have line and neutral or ground.

[@lurkingcorsa10]

could I use Tranfo from the other devices..? and..wht capacity is your trafo.?

[@diecksl]

Yes, of course you can. Any transformer working with mains frequency (50/60 Hz) will do, but it has to be a powerful/bulky model with thick wire at the primary coil, since the wire will carry somewhat between 8 - 15 amps @ 230 V for a few seconds while welding. The transformer shown in the video was a 800 or 1000 watts microwave transformer if I remember correctly. Maybe an old isolation transformer or one from a big power amplifier would work?

[@lurkingcorsa10]

but .. why, every these tutorials use microwave trafo, not others..? overall.. thnkss..(Y)!

[@diecksl]

Simple: Microwave transformes work well and they are cheap. You can get them for 10 - 20 EUR/USD on eBay or from an old microwave. Do you have a transformer in mind which you want to convert to a spot welder?

[@lurkingcorsa10]

trafo from old electronics, as like: tv or refrigerator..! howw..?

[@timmax4817]

Too bad , you have 220 volts there, but in USA we have 110, i think it would work differently

[@diecksl]

No, it wouldn't! When you remove a microwave transformer from a US microwave it is constructed for your domestic market. So the manufacturer has designed the primary/secondary coils with a different number of turns, but the ratio is the same. You can also vary the output voltage of your secondary by changing the number of its turns (e. g. build a secondary with only one turn, measure its output voltage and divide your desired target voltage by that number -> the result is the number of turns you need on the secondary). Please be careful, even 110 volts can be dangerous.

[@willemvanvliet3493]

then you take to of them ,...... ass.....

[@jamiejoker118]

If you add an inductor to Fan it will run faster

[@Ananta_Madhab_Creation]

Can I use 4 UPS transformer for this?

[@diecksl]

It depends.. you can use more or less any 50/60 Hz iron core transformer, as long as its primary winding is large enough to transmit some decent power (1000+ watts). An UPS transformer sounds like a ferrite core type, this type of transformer needs an extra circuit since it works in the kHz range. Do you have a link to the transformer you have in mind?

[@irham9856]

👍👍👍

[@Michel-Artois]

Belle réalisation!! Le Pb avec ces transfos, c'est que la chaleur Max arrive lentement : le métal brûle sans fondre et la soudure se fait mal. Ce serait mieux de faire un câble secondaire (2 tours) avec 8/10 brins de 5mm qui vont serrer la partie centrale du transfo sans laisser de vide, puis on tord ces brins en // . Là on a un Max d'amps qui viennent vite. Il faut beaucoup d'amps sur un temps très court , et les bobinages chauffent peu. De toutes façons ce transfo n'est pas fait pour des temps de soudure longs ,et simplement pour du métal très fin . Pour souder des accus au nickel je rajoute une carte pas chère (indispensable pour ne pas burner les accus) comme celle-ci : fr.aliexpress.com/item/33040580897.html?spm=a2g0s.9042311.0.0.31736c373Yj8KU Prendre aussi le transfo 9V AC pour l'alimenter . La carte a un relais 9V pour la pédale ou le bouton qu'on peut mettre sur les électrodes , et c' est beaucoup mieux. Elle régule le temps en millisec. et elle permet une régulation de l'ampérage de sortie. Il faut quelques essais pour trouver le bon réglage selon l'épaisseur du nickel. J'espace un peu les soudures pour le pas brûler le triac (c'est du "made in China") . Je contrôle aussi la bonne qualité des soudures du triac , c'est parfois léger , je rajoute de la soudure , et je le plie sur une petite plaque d'aluminium (radiateur). Quand la carte est morte , c'est presque toujours le triac qui a surchauffé. Le petit transfo (9V) n'est pas de grande qualité, mais ce n'est pas facile de trouver un 9V en AC (alternatif) Sans carte, les électrodes se soudent parfois sur le nickel et il faut arracher tout de suite les électrodes en tirant , sinon on fait très vite un trou dans l'accu. Amicalement

[@hewelgeduwelbeh7418]

I tried my output of only 0.25 volts using 25 mm cable with 3 loops .. why ...?

[@diecksl]

Two things come to my mind: 1) What is the input voltage in your country? In my country its 230 Volts AC 2) Have you removed the shunts in your transformer? The shunts are two pieces of metal between both coils, they limit the amps on the secondary (which is not what we want). See here: i.stack.imgur.com/TzfLH.png

[@diecksl]

Safety tip: You should replace the shunts with thin wooden board. The wood acts as insulation between both coils.

[@hewelgeduwelbeh7418]

My voltage of 220 volts AC in 50 Hz, I dispose of its boundary, and do not change it because I thought the cable had been there ... what's this isolation may be caused because the coil primarynya damaged electrical home several times because I broke up

[@vrsf.concept]

Vidéo très intéressante. Merci.....

[@hewelgeduwelbeh7418]

how the size of the replacement cable

[@diecksl]

he Welgeduwelbeh The red cable is 25 mm2. As it turned out, this is not enough. If you build your own spotwelder, try to go for 30 mm2 - 35 mm2

[@jiwaelectro]

Need use relay for foot pedal wiring...more safer...

[@sirajansari8302]

How much voltage is the torchfermer

[@diecksl]

The primary runs on 230 volt, the secondary produces about 2,8 volts (0,92 volt/turn).

[@anassayyed6797]

Siraj Ansari

[@rikuyadav2393]

Bhai yah mere ko bhi chahie

[@vickydj5966]

Plzz wire size

[@diecksl]

Of the secondary? The bigger, the better (as long as you can fit the right amount of turns into the transformer). If I remember correctly, I used 16mm2 cable

[@TheRannyG]

Hallo Daumen hoch. ein super Projekt. ich baue mir auch gerade einen punktschweisser. als Anregung für dich, du kannst zb einen ic 555 verbauen. dann kannst die einschaltdauer einstellen. gibts beim conrad um ca 13€ als timer Bausatz. lg

[@diecksl]

Gerald R Vielen Dank! Ja, das mit dem 555 habe ich in anderen Videos auch schon mal gesehen. Wollte halt erstmal rasch ein Ergebnis sehen :-) Aber ich habe inzwischen schon wieder einiges verändert an dem Gerät (so ein Projekt ist ja nie fertig), wenn ich einen Timer verbaue poste ich natürlich ein Video dazu

[@sujatanandi3230]

Gerald R arakta

[@djmlldn3894]

Goood...👍

[@omarionbackflip99]

so you just rap round the wiyer

[@jabastindhanrajdhanraj6685]

Jabastin dhanraj.F

[@aboobaida100]

goooooood

[@diecksl]

ااه يا زمن زمن العجايب Thanks

[@roushhawley8438]

thats 4 AWG wire, if you use 2 AWG wire you get twice the amps (obviously)

[@TheSpecial43004]

1.3kA is twice 946A? Your math skills are broken dude

[@TheSpecial43004]

(obviously)

[@sibi.ssibi.s9121]

Gm..

[@thanhtungdanh5894]

Go

[@mihailovsasa5955]

Da

[@Tuoi_Tho_TV]

helo

[@AlphaTroniks]

I would have simply drilled a hole and inserted the loop handle in the tin can instead of welding a drilled piece to hold the loop handle!

[@diecksl]

AlphaTroniks Of course! But hey - where is the fun? :-)

[@kudapadi5429]

Lejf Diecks Yeahh..that it fun,otherwise it just an example to show how it on working is gonna look like..

[@kudapadi5429]

Lejf Diecks Hi sir,can i ask u something? Why the burning from electrode kind a look like it just auto-stop after a few second of the weld start even u not release the clamp yet ? Because that what i am seeing and kind a weird for me, did the fact is u just releasing it but i'm seeing opposite of what just happening... or Did it really stop by itself because of the contact spot that start burning for a few second just create some layer of burn effect on it then make they non contact to the welder again, is that what is really happening? Sorry for my BADDDDD english,i'm just an Asian boy that try to learn some knowledge from other DiYers on KZbin.. I hope u can understand what really i'm try to get from u,that unclear of understanding or misunderstanding of mine thats what just wondering me for a while? It just stupid question i think but it really need for me to clearly understand what the right concept of that things truely work...

[@jean-pierrefle3471]

in deusch ist besser!!!