tomjasz
1 GW
BTW 3 boards are $27.
JP spot-welder, FET-switched, timed adj. pulse
- Thread starter okashira
- Start date
BoomerChomsi
1 kW
Yeahh take some some time for getting better 8)
I can wait....
I can wait....
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
Wow! 3 boards are 27? That makes the 40 for PCB seem even more outrageous..... Cool I'll just order the 3 boards... Anyone need one pm me..... Hey that's fine you can have your opinion when I work on stuff like this or help out others I never try to make unreasonable profit.. In your opinion 40 bucks for a PCB and 65 for two battery cables with copper tips is a hell of a deal... To me its gouging. IMO charging that much spits in the face of the spirit of this forum.... It is awesome riba has contributed so much but I don't want to pay that kind of markup so insult away if you want and sorry for disrespect I don't like to feel like I'm being taken advantage of.... Almost all of this info is gleaned from other sources then put together its all available on here and other electronic sites .... So Im Sorry our opinions differ I'm always going to deal hunt especially on DIY stuff. Good luck. Get well.... If anyone needs a board PM me
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
I hope no one misinterprets me... I simply want to keep this info and parts available at a reasonable price and since kits arent available and no word on when they will be it seems to me the best thing to do is to make a alternative way to get / sell the parts so people can continue to build these as they are a great thing for this hobby. it allows us to build our own packs and cut out the Chinese battery salesmen who very often lie about capacity or use counterfeit cells. So im sorry if I came across like a jerk I just felt like 65 for probes and 40 for a board only and your already at 105 dollars not including components I can understand the price of a complete kit being 160 that makes sense because of the convenience of having it all in once package and not having to source everything separately. Now that kits arent available the convenience is gone we still have to source all our parts ourself so i dont feel the price is justified out of kit form for a board only. This information is all open source and available online im not trying to steal or rip anyone off... simply keep these available for cheap for now i just want to build one for myself im in no rush as i hand soldered my first pack... 142 cells and its working great but i have plans to build the same capacity pack with 80 3400 mah cells. If Riba is not going to offer kits i think it is a shame if no one steps up and fills in because this is a good thing to have available. I wish the best to Riba and sending good wishes for good health. This was not meant to be taken as a personal attack. im just trying to build a quality welder as cheap as i can... Let me reiterate i would gladly pay 160 for a complete kit minus the probes but the problem is that isnt an option anymore and if i have to source everything myself im doing it as cheap as possible. sorry if that makes me an ass nothing personal....
edit... just noticed the assembled welder would be 100 if it was available this would be a great value but its not available and no ETA if/when it ever will be again.
edit... just noticed the assembled welder would be 100 if it was available this would be a great value but its not available and no ETA if/when it ever will be again.
destro23
1 W
Shroom how much would you sell me a working spot welder?
tomjasz
1 GW
Nah shroom, we're clear, you're pretty much clueless. You want people to work for $3 and hour if you're buying but probably think you're worth $25.
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
So Tom explain to me where im asking anyone to work... I said the exact opposite in kit form sure its worth the cash.... but just reselling boards at a huge markup isnt "working" the work done on this was gleaning info from other resources and putting it together... this welder is not riba's invention.... i dont understand why everyone is up on his nuts like they are... i just want to build the welder for as cheap as possible if the kits were available for 100 bucks as they used to be id gladly buy one... but they arent available... so get as butthurt as you want.... doesnt affect me. if the kits were available id gladly buy one... so you are mad that i dont want to pay 40 bucks for something i can get 3 of for 27... whatever... that makes as much sense as Donald Trump for president...
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
destro... im trying to get one together for myself for a reasonable price. I have no intention of taking business away from Riba and selling welders but I dont understand why it would be a problem if he isnt offering them for sale anymore... after i get mine together and test it i will get back with you but honestly im just trying to build this at a reasonable price so it isnt as expensive as i could buy a pre-built one for when you add in the cost of the battery with the "updated" prices the cost of this welder is damn near close to just buying a pre-built one. I think this welder does a better job but hell you still have to assemble it and now source the parts and board. If anything i could see offering kits just because there is obviously a need as a lot of people have pm'd me asking for them. I honestly have no desire to do that but the attitudes around here are making me want to kind of just in the spirit of open source and helping out others for no reason other than the joy of helping the community. Back in the day that wasnt something that was scoffed at.
This is a thread to document Riba's spot welder not about how you are a cheep sob with out a ounce of creative thinking on how to make a set of boards worth your time and money. No matter what Riba wants to charge he can because it's his design and his work. He is dealing with health issues and I made the mistake of posting links on his thread to help people like you out. Where as a person who truly wants to put effort forward would have found all the info in another thread and never needed it spoon fed. Because you have the lack of understanding and what not I will also spoon feed you a little of what is to come. Your attitude will effect how the rest of the forum will work with (or against you in this case) and you will find for years to come very little help because of your lack of respect. Good day. And don't PM me ever again.
Doctorbass
100 GW
I also know Riba is facing health issue and i hope he will recover well.
Anybody have spare PIC and fet driver chip of the J-P spotwelder?
or even have the HEX code so i can program my own chip? I blown my 2 chips and my spotwelder is finished and only is missing two working chip to operate.
any help will be apprecaited.
Thanks!
Anybody have spare PIC and fet driver chip of the J-P spotwelder?
or even have the HEX code so i can program my own chip? I blown my 2 chips and my spotwelder is finished and only is missing two working chip to operate.
any help will be apprecaited.
Thanks!
Attachments
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
Oh I'd not ask for the precious hex code or you will be treated like Satan... Honestly if I gave 2 shits about what people thought I'd make a new login oh noes people on the interwebs don't like me whatever will I do... Ffs read what I've actually said and instead of being a mindless minion use some reasoning. The reason I posted in this thread is it is referenced so many times on the forums well the welders or kits aren't available anymore... I'd understand all the negativity if I was trying steal business from Riba... I'm not. they are not available for sale. There is demand for kits and built units. I'm not trying to win a popularity contest I'm just trying to build this as cheap as possible. others feel the same as I have numerous messages backing what I'm saying. It sucks Riba is sick but that doesn't equal I have to spend IMO a over inflated price for boards that were just fabbed at a fab house. Ffs butthurt as far as the eye can see... I have a pic programmer and will flash pics for solely the price of the pic and shipping if someone can send me the hex code.
Doctorbass
100 GW
Offroader said:
yes i guess, why,do you have one spare?
Doctorbass said:
I actually do have a spare set of both those chips as I asked riba if he could send me two PIC chips and he was able to do that, I only have 1 PIC chip unused , he also sent me a spare fet driver. You see the thing is that I don't know why my original PIC chip failed and I am relying on that as a backup, if it failed once, it may fail again. If my PIC chip ever failed again my welder would be useless without a spare chip.
I am not in any rush here for a backup chip as I don't plan on using my welder any time soon. The chip I have installed now has not given me any trouble for my whole pack build, it died actually when I first got it after testing some welds. But I would like to have a backup chip in case mine fails again.
I can mail you the spare chips but I think it is best you try and copy the PIC chip so we can make sure we have spares.
One thing that Riba sent me in the pic below and will allow you to swap chips fast without soldering them into the board.
The original riba2233 "for sale" thread can be found here:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=68865&start=950#p1197893
https://endless-sphere.com/forums/viewtopic.php?f=31&t=68865&start=950#p1197893
r3volved
100 kW
Commenting to subscribe (not sure how to otherwise). Didn't realize this discussion threaded out...riba created a monster
tomjasz
1 GW
Useless drivel.
shr00m
10 W
- Joined
- May 18, 2016
- Messages
- 75
again. i wasnt whining. i asked if anyone was interested in going in on boards.... you are the only one coming around and slinging insults that are not warranted... if you want to send Riba your whole bank account feel free to do so but otherwise im getting back to sourcing and building these welders... take the drama with ya tom... I understand the friendships and all of that... again i felt it was stupid to pay 40 bucks for a pcb when i can get 3 for 27.... if that makes me an asshole i guess i am but the truth of the matter is many other people feel the same way they just dont want to burn in flames like i have been I have the pms to prove that other people want to be able to get these kits and boards for cheap and dont feel like waiting around indefinitely until they are available... and my "whining" accomplished getting the thread split so we can go back to working on providing links to get boards and components easily and not be in a weird place of feeling bad about wanting to build a welder because someone is sick (which is horrible and im really sorry about that) again. I get loyalty but this is fanboy stuff right here the emotion and drama just doesnt make any sense... whatever man. DIY 4 LIFE.
I've been reading and enjoying everyone's posts - lots of experience to share here - so I thought I'd throw mine out there as well.
I have the same 6 FETs driven by 1407 driver like most designs here.
Been blowing a few FETS now and then and even a couple of the driver chips shorted the output high - that was a "long weld pulse'.
Here's what I found / learned so far to share.
1. FETs usually go after they have been weakened and overstressed after a few too many cycles or when one of them gets more than
its share of current. This can happen when there are minor differences in their turn on time - likely caused by slight gate voltage differences or even PCB board layout issues. Since the gate is voltage sensitive using separate (6) 82 ohm resistors off the driver chip is the best bet. Now at least they will all see the same output pulse and have a chance at being turned on at the same time. If you were to have a single drive current resistor then the device that turned on first would 'hold down' the drive voltage further amplifying any device differences.
Conclusion 1. - use separate, closely matched drive resistors. (same as riba layout). For PCB layout try to drive the string with about equal length traces etc. to each FET.
2. Since its not practical to sort FETs with perfectly matched gate turn on thresholds - mitigate differences in their turn on time, to avoid large current sourcing differences between the string at their Drain/ Source. Most of the welders out there I suspect already do this by having a few feet of weld wire to the hand held probes. If you did as I did though - build a dual probe type bus bar fixture with short (low inductance, low resistance) current paths then you may have a problem. The shorter lower inductance leads have very fast current rise times. If one FET (due to its lower gate threshold) turns on first then that first FET to turn on will source a large non shared current (only for a while 'til its smoke). This FET failure usually shows up as a constant 12V across the probe leads - all my FETs have failed shorted. By adding some lead length and or some inductance to the leads - you increase both R and L and put a short (few microsecond) time constant in the current rise time. Now slight differences in the gate thresholds are mitigated during the 'delay' 'til full turn on, as the other FETs catch up, and they are all on (sharing current) by the time the current peaks. We're only talking microseconds here - but it makes a difference.
Conclusion 2. Resistance and added inductance from 5' leads back to Battery+, coiled into 5 to 6 turns approx. 2-3" diameter works fine. This adds about 10usec to the current rise time.
3. Adding inductance to the power switching circuit now creates other issues. The flyback current (google it) is now much larger and creates a large voltage spike across the FET output, trying to fully shut off. This spike of a high frequency is also easily coupled into the entire circuit an may appear on the input power or output driver of the controller. In my case more than once it took out the 1407 chip - short from its output to its 12V Vcc input. With that the FETs stayed on. Not good unless you like to dangerously drill holes in the end of your 18650 cells like a plasma welder.
Conclusion 3. Two solutions here were needed to solve the issue on my setup. A.) as earlier discussed on this thread (see riba et.al. - use of a Schottky diode to dissipate the flyback spike. and B.) Don't use the 12V battery as a source for the controller circuit. I was and am still doing this BUT now I run total separate, twisted leads directly (with a fuse) back to the B+ and B- battery posts. No weld currents are common to the controller power supply current. Also try to route leads away from or perpendicular to any power leads.
One last note - helpful in my analysis and testing was to put a .2ohm (about 70A current peaks) resistor across my probe leads. Now during the various circuit tuning/oscilloscope experiments I had a repeatable, easily measured set up. I looked at both the current waveforms across the load, as well as the power input to the controller (AC coupled to focus on any noise from the pulse wiring). Now it was fairly straight forward to do A/B comparisons on various 'fixes'. During acutally spot welding I measured currents in the range of 1200 to 1400 peak amps using a separate shunt at the battery.
Hope these experiences help.
Cheers,
Geekineer
I have the same 6 FETs driven by 1407 driver like most designs here.
Been blowing a few FETS now and then and even a couple of the driver chips shorted the output high - that was a "long weld pulse'.
Here's what I found / learned so far to share.
1. FETs usually go after they have been weakened and overstressed after a few too many cycles or when one of them gets more than
its share of current. This can happen when there are minor differences in their turn on time - likely caused by slight gate voltage differences or even PCB board layout issues. Since the gate is voltage sensitive using separate (6) 82 ohm resistors off the driver chip is the best bet. Now at least they will all see the same output pulse and have a chance at being turned on at the same time. If you were to have a single drive current resistor then the device that turned on first would 'hold down' the drive voltage further amplifying any device differences.
Conclusion 1. - use separate, closely matched drive resistors. (same as riba layout). For PCB layout try to drive the string with about equal length traces etc. to each FET.
2. Since its not practical to sort FETs with perfectly matched gate turn on thresholds - mitigate differences in their turn on time, to avoid large current sourcing differences between the string at their Drain/ Source. Most of the welders out there I suspect already do this by having a few feet of weld wire to the hand held probes. If you did as I did though - build a dual probe type bus bar fixture with short (low inductance, low resistance) current paths then you may have a problem. The shorter lower inductance leads have very fast current rise times. If one FET (due to its lower gate threshold) turns on first then that first FET to turn on will source a large non shared current (only for a while 'til its smoke). This FET failure usually shows up as a constant 12V across the probe leads - all my FETs have failed shorted. By adding some lead length and or some inductance to the leads - you increase both R and L and put a short (few microsecond) time constant in the current rise time. Now slight differences in the gate thresholds are mitigated during the 'delay' 'til full turn on, as the other FETs catch up, and they are all on (sharing current) by the time the current peaks. We're only talking microseconds here - but it makes a difference.
Conclusion 2. Resistance and added inductance from 5' leads back to Battery+, coiled into 5 to 6 turns approx. 2-3" diameter works fine. This adds about 10usec to the current rise time.
3. Adding inductance to the power switching circuit now creates other issues. The flyback current (google it) is now much larger and creates a large voltage spike across the FET output, trying to fully shut off. This spike of a high frequency is also easily coupled into the entire circuit an may appear on the input power or output driver of the controller. In my case more than once it took out the 1407 chip - short from its output to its 12V Vcc input. With that the FETs stayed on. Not good unless you like to dangerously drill holes in the end of your 18650 cells like a plasma welder.
Conclusion 3. Two solutions here were needed to solve the issue on my setup. A.) as earlier discussed on this thread (see riba et.al. - use of a Schottky diode to dissipate the flyback spike. and B.) Don't use the 12V battery as a source for the controller circuit. I was and am still doing this BUT now I run total separate, twisted leads directly (with a fuse) back to the B+ and B- battery posts. No weld currents are common to the controller power supply current. Also try to route leads away from or perpendicular to any power leads.
One last note - helpful in my analysis and testing was to put a .2ohm (about 70A current peaks) resistor across my probe leads. Now during the various circuit tuning/oscilloscope experiments I had a repeatable, easily measured set up. I looked at both the current waveforms across the load, as well as the power input to the controller (AC coupled to focus on any noise from the pulse wiring). Now it was fairly straight forward to do A/B comparisons on various 'fixes'. During acutally spot welding I measured currents in the range of 1200 to 1400 peak amps using a separate shunt at the battery.
Hope these experiences help.
Cheers,
Geekineer
pguk
100 W
That was interesting reading, thank you.
My brain board currently outputs through a single gate resistor, but it does seem that this is not best practice - IRF app note AN941 explicitly says to use separate gate resistors. "It is common knowledge that paralleled MOSFETs must have individual gate resistors."
My brain board currently outputs through a single gate resistor, but it does seem that this is not best practice - IRF app note AN941 explicitly says to use separate gate resistors. "It is common knowledge that paralleled MOSFETs must have individual gate resistors."
Thank you for finfing that reference. Biggest problem nw is weld spot form the probe attached to Battery+ is several times larger deeper than the one next to it....sometimes burning through. Probes have been cleaned and sized to same tip diameter??????
pguk
100 W
Curious. That's not a problem I have seen.
I rebuilt my power stage this evening with another set of 1324 FETs (24v rated), and added individual gate resistors this time. These FETs do have good avalanche current handing figures, but my concern is still the back emf at turn off (27v plus) which is responsible for killing these??? I have a few of these built already so I'll see how long they last this time
I rebuilt my power stage this evening with another set of 1324 FETs (24v rated), and added individual gate resistors this time. These FETs do have good avalanche current handing figures, but my concern is still the back emf at turn off (27v plus) which is responsible for killing these??? I have a few of these built already so I'll see how long they last this time
