My understanding of the improved weld performance from using two pulses is that the first pulse heats up the contact areas enough to “burn” or vaporize away any contaminants present on the surface between the electrodes and surface to be welded, causing a much cleaner weld to happen on the second pulse, as opposed to the full weld current being applied as one large pulse, and those two things happening simultaneously, yet less efficiently. Also it’s worth noting that the pulse durations needed to weld nickel strip to the surface of a battery will be greater than those needed to weld only nickel strips together. This is normal, as the surface of the battery is much larger in mass than a thin piece of nickel strip, and will require more power to sufficiently heat the battery surface and nickel strip at the point of the electrodes to create a good weld.
Thanks for this. 4s2p 5000mah old 30/50c lipos work for 2-3 cell packs great but varies as voltage drops off. I added an 83f 6 cap bank and set the pwr supply to 16v @ 2a and can do 50-60 welds to the point the pens jet too hot. During this I had a small fan keep the board temp under 37c, it hit 48 with no fan @ the same time the pens get uncomfortable. The only thing I will do now is add jacks for the the pens to switch out as they heat up thanks ps, all power connects are bolted to the board. the packs are 12g xt90 the cap bank is 10g direct bolted and the xt60 is charge.
With the board with 5 fets . I added the 5 to the back and used a separate power source for the board. I did not connect the battery positive to the board. I have thousands of welds on the board
Because you are using a separate circuit to power the MCU and the phototransistor, (driving the FET gates) you have decoupled the FET gates from the power circuit. This is one method of decoupling the welder board’s control logic from the power circuit, because the separate circuit being used for the MCU is not part of the power circuit dumping current into the weld. Although this method is effective at decoupling the MCU, it is less convenient, as two circuits are needed to power and use the welder. Many people use a battery pack capable of high current for the power circuit, and repurpose a 12v wall adapter (the adapter has to have enough output that it can drive the FET’s past the miller-plateau without going into over-current protection or the FET’s will blow when the adapter goes into protection shutoff) The downside to that method of decoupling is it isn’t as portable or convenient as just plugging the welder into a pack and off you go. This is especially convenient if portability is needed. It is also more complete from a design standpoint, as ideally a portable spot welder should be able to be used with just the power battery. But there’s nothing wrong with using a separate circuit to power the control logic if portability isn’t a concern or that’s just what someone prefers to do. It does require another additional circuit to power the logic though.
Well they are 2 different level products, the KEKK is cheap and possibly needs a mod but may handle the job if you don't need to use it professionally while the Malectrics os constructed with more protection and design in mind and more capable and costs about 8-10x the price depending on the options you add. If you want a more reliable, capable and professional product then Malectrics is definitely the choice. If you just need to have a handy spot welder for a few welds without exceeding .15-.20mm and can do the decoupling mod if needed then the KEKK is fine.
Check my other video on the Purple Spot welder where I show how to do the decoupling mode with an additional capacitor resistor and diode, it's in my playlist on my channel page.
@ManAndTechOfficial theoretically yes, you can wire the positive side of the 470uF cap to the opto + after having cut the trace from the battery + side. Use good quality wire.
any info on running these on 12v lead acid, I have tried what was a good diesel battery but I am not getting good results despite the battery being good for a 4a discharge without sagging. I have a few 12V 24ah but I think i would need 2 or 3 in parallell to give the 100A+ to weld. A 3 cell lipo would be the obvious way but I have heard that these will die in 1-2 years if unused
A single 24Ah AGM lead acid battery may suffice *if* the battery is in good working order (i.e. it can deliver the rated CCAs). I explain this and other considerations in my other videos and FAQs so please check them out - they are in my spot Welder playlist.
I measured the output of a similar device to the one in the video, by dumping the pulses into a large shunt resistor with a few milli-ohms resistance. It looks like the main pulse I get is about 1500A. I am using a proper gate driver chip so my pulses are much cleaner than on an un-modded device. Also, mine is now driven by an STM32 MCU because I wanted to define the pulse shape myself. This device originally blew up spectacularly after a few uses, so it's almost a completely different thing after the extensive repairs and subsequent mods (and a fresh set of FDBL9403 fets) but now it's very reliable and I don't expect it will explode again anytime soon!
Also, the transients are immense enough that you should probably make sure you have a fast diode across V-supply and GND to prevent negative transients from the cable inductance.
Well that's because I attended a British school when I lived abroad for over a decade and a half (it's kind of my mothertongue as I actually learned English before italian and my parenta spoke to me in English!).
Hi, nice video, Can you make video about spot welder with 12 mosfet, like in the link th-cam.com/video/09D6r1U1f1M/w-d-xo.htmlsi=QQQe2mmPdtgi7uqw And compare witch is better, of course explain how to weld resistor, diode and capacitor. Also explain SEG1, SEG2, SEG3, energy and delay. And how to remake to manually weld not automatically. Thanks, Bye.
My understanding of the improved weld performance from using two pulses is that the first pulse heats up the contact areas enough to “burn” or vaporize away any contaminants present on the surface between the electrodes and surface to be welded, causing a much cleaner weld to happen on the second pulse, as opposed to the full weld current being applied as one large pulse, and those two things happening simultaneously, yet less efficiently.
Also it’s worth noting that the pulse durations needed to weld nickel strip to the surface of a battery will be greater than those needed to weld only nickel strips together. This is normal, as the surface of the battery is much larger in mass than a thin piece of nickel strip, and will require more power to sufficiently heat the battery surface and nickel strip at the point of the electrodes to create a good weld.
Excellent explanatory video!!! Thank you very much!!!
I've been waiting for you to do the k100!
Well done excellent info on this welder enjoyed the demo great job
Thanks for this.
4s2p 5000mah old 30/50c lipos work for 2-3 cell packs great but varies as voltage drops off.
I added an 83f 6 cap bank and set the pwr supply to 16v @ 2a and can do 50-60 welds to the point the pens jet too hot. During this I had a small fan keep the board temp under 37c, it hit 48 with no fan @ the same time the pens get uncomfortable.
The only thing I will do now is add jacks for the the pens to switch out as they heat up
thanks
ps, all power connects are bolted to the board. the packs are 12g xt90 the cap bank is 10g direct bolted and the xt60 is charge.
Truly helpful information. Thanks so much!
With the board with 5 fets . I added the 5 to the back and used a separate power source for the board.
I did not connect the battery positive to the board.
I have thousands of welds on the board
Because you are using a separate circuit to power the MCU and the phototransistor, (driving the FET gates) you have decoupled the FET gates from the power circuit.
This is one method of decoupling the welder board’s control logic from the power circuit, because the separate circuit being used for the MCU is not part of the power circuit dumping current into the weld.
Although this method is effective at decoupling the MCU, it is less convenient, as two circuits are needed to power and use the welder. Many people use a battery pack capable of high current for the power circuit, and repurpose a 12v wall adapter (the adapter has to have enough output that it can drive the FET’s past the miller-plateau without going into over-current protection or the FET’s will blow when the adapter goes into protection shutoff)
The downside to that method of decoupling is it isn’t as portable or convenient as just plugging the welder into a pack and off you go. This is especially convenient if portability is needed. It is also more complete from a design standpoint, as ideally a portable spot welder should be able to be used with just the power battery. But there’s nothing wrong with using a separate circuit to power the control logic if portability isn’t a concern or that’s just what someone prefers to do. It does require another additional circuit to power the logic though.
wich would you recomend , the K100 or the malectrics V4
Well they are 2 different level products, the KEKK is cheap and possibly needs a mod but may handle the job if you don't need to use it professionally while the Malectrics os constructed with more protection and design in mind and more capable and costs about 8-10x the price depending on the options you add. If you want a more reliable, capable and professional product then Malectrics is definitely the choice. If you just need to have a handy spot welder for a few welds without exceeding .15-.20mm and can do the decoupling mod if needed then the KEKK is fine.
@@Luca_Techy Thank you , that 100% answers my question . I'll be building a malectrics then .
Is it possible to do same wiring thing for old board also?
Check my other video on the Purple Spot welder where I show how to do the decoupling mode with an additional capacitor resistor and diode, it's in my playlist on my channel page.
@Luca_Techy hi I seen that one, is possible to do without capacitor, resistor and diode? like you done it for this new one.
@ManAndTechOfficial theoretically yes, you can wire the positive side of the 470uF cap to the opto + after having cut the trace from the battery + side. Use good quality wire.
@@Luca_Techy Can you pls make one video for that
any info on running these on 12v lead acid, I have tried what was a good diesel battery but I am not getting good results despite the battery being good for a 4a discharge without sagging. I have a few 12V 24ah but I think i would need 2 or 3 in parallell to give the 100A+ to weld. A 3 cell lipo would be the obvious way but I have heard that these will die in 1-2 years if unused
A single 24Ah AGM lead acid battery may suffice *if* the battery is in good working order (i.e. it can deliver the rated CCAs). I explain this and other considerations in my other videos and FAQs so please check them out - they are in my spot Welder playlist.
You have to look at the CCA you need 900ish or more
I measured the output of a similar device to the one in the video, by dumping the pulses into a large shunt resistor with a few milli-ohms resistance. It looks like the main pulse I get is about 1500A. I am using a proper gate driver chip so my pulses are much cleaner than on an un-modded device. Also, mine is now driven by an STM32 MCU because I wanted to define the pulse shape myself.
This device originally blew up spectacularly after a few uses, so it's almost a completely different thing after the extensive repairs and subsequent mods (and a fresh set of FDBL9403 fets) but now it's very reliable and I don't expect it will explode again anytime soon!
Also, the transients are immense enough that you should probably make sure you have a fast diode across V-supply and GND to prevent negative transients from the cable inductance.
@@un2mensch its been a while since i knew about diodes. What kind are fast. Schokky (in reverse across the supply?)
For the old purple board, can I use 16V 1000uf or 35V 470uf?
The 35V 470uF will do.
@Luca_Techy I currently used 16v 470uf + 22ohm. It works much better.
Hi thanks for the video. How it's possible your english so good?? I saw in your old video you're italian.
Well that's because I attended a British school when I lived abroad for over a decade and a half (it's kind of my mothertongue as I actually learned English before italian and my parenta spoke to me in English!).
What can we modify to this model? th-cam.com/video/3tvygy0iqqI/w-d-xo.html
For the old purple board
Check my Spot Welders playlist, I explain how to mod this older model in another video.
Hi, nice video,
Can you make video about spot welder with 12 mosfet, like in the link th-cam.com/video/09D6r1U1f1M/w-d-xo.htmlsi=QQQe2mmPdtgi7uqw
And compare witch is better, of course explain how to weld resistor, diode and capacitor. Also explain SEG1, SEG2, SEG3, energy and delay. And how to remake to manually weld not automatically.
Thanks,
Bye.