If you look at the board it is hard to believe that it is 3oz copper but by running your fingers over the edges of the copper you can feel the the difference. The board is also heavier. The camera and lights make the silver color on this board look like it is copper.
Can't wait to get mine!
ReplyDeleteMy fet board arrived today. Thanks Fritz! I am only waiting on the fets.
ReplyDeleteYou are welcome Mike, I will send the new manual for these boards out tonight.
ReplyDeleteWOW! This board is nice! Very beefy. You guys will really like it. Should hold up to allot of abuse:-) I certainly cant say the same about the one I built;-) ShawnC
ReplyDeleteThese boards are alot better than the boards I made. I can feel the weigth difference of the copper. Great job Fritz, thank you..
ReplyDeleteFritz, these new mosfet boards look great! Much better than the one I built. Thanks for continually looking for a better solution
ReplyDeleteThanks Damian and Jack, I have only one FET board left.
ReplyDeleteGot mine in yesterday. Really nice
ReplyDeleteDON
ReplyDeleteJUST GOT MY BOARDS TODAY... THEY WERE BEAUTIFUL, CAN'T TO WAIT TO GET MY PARTS, I'LL KEEP YOU POSTED FRITZ
I just tested two XCP-1 "1.5 farad" caps. Spec is 2 milliohm ESR.
ReplyDeleteBoth units had a capacitance of 0.15F (1/10th the rated value!). ESR was 6.5 and 26 milliohms. Discharge energy was 7.2 joules at 12V (should be 108 joules)
ESR measured with a ESI 2150 VideoBridge. Capacitance measured by timing charge to 10V when fed by 100.000 mA constant current ultra-precision power supply/HP3458A 8.5 digit meter. Discharge energy calculated from current waveform into a 0.0100 ohm resistor. LED board removed.
hello
ReplyDeletei like to know where i can get the 2 24volt transformers?
Hi Fritz, can you tell me what was your calculation that sum 600ws
ReplyDeleteThanks.
Damian, (Capacitance x voltage x voltage)/2
ReplyDelete(3 x 20 x 20)/2 =600
Thanks Fritz.
ReplyDeleteHow many people have gotten this project finished? What are you using for a case? How is the final project working for you?
ReplyDeleteHi Fritz, I'd like to get a Mosfet PCB. Were you able to get about 10 people to pay up front? Thanks
ReplyDeleteDennis, I found a Tektronix TM405 case. It looks to be slimmer than a PC case. I have to check out the fit of the major parts first. It sure looks like a nice case.
ReplyDeletelbbarnes, not yet. Even If i get enough people interested in the FET boards it will take 4 weeks to have it manufactured.
ReplyDeleteHi Fritz, I wanted to purchase the CONTROL PCB WITH ALL SM COMPONENTS INSTALLED + uP, but it's currently out of stock. When will it be available? Thanks.
ReplyDeleteI was wondering, do you really need the FET board. For your first tab welder, did you use an FET board?
ReplyDeleteI will build a control PCB with all the SM Components on special request. Shoot me an email.
ReplyDeleteThe first welder used a contactor. The paperwork for that welder are packed far away and I won't be able to help you with that.:)
I got my heatsinks srilled and tapped. If Fritz does not mind I have the welder's progress here on my blog: http://rotordesign.com/blog/
ReplyDeleteThanks for the update Mike. I think I'm going to make a new page with welder photos from you guys on it. Please send me your photos!
ReplyDeleteHere are a few thoughts I have. How about a list of settings and materials that people use? For instance, for me 12v works well with .005" nickel, but I need to go to 14V for .010" nickel. Sorry, I don't have pulse times in front of me. The other thing I would like to see is more shared information on cases and probes. I want a better solution to interface 1 gauge cable to 1/4" copper rod. Is there a better material for welding nickel than copper? Personally, I thought the hardest part of building the welder for me was drilling and tapping the 18 heat sink holes.
ReplyDeleteThanks guys!
It's a good idea RStar for materials but not the settings though. Every one uses different capacitors and cable sizes/ probes so settings are going to differ. Shawn makes cases and he will also make custom probes on request. All these things are in here and you just need to read the comments to find it(very difficult though). I will see if I can write a summery about everything and maybe open another page with material lists.
ReplyDeleteI found that 0.007 stainless works really great and makes a weld so strong that you can not break it with your bare hands.
Drilling and tapping the heatsinks are really easy. You could have used Gc-Prevue to print DRILLandEDGE.qwk. place the paper over your heatsink and used a center punch to mark the spots where to drill.
I think the settings are still valuable since it will show the relative changes between materials that each welder will have with different cables/probes. I'm going to use a similar gauge to what I saw at Fritz's. Something like #4 wire? That way the interface to the probes will be much easier. I dreaded the hole tapping as well. Glad I have a machine to help. I could not get GC-Prevue to open the .qwk files. So glad to hear .010 stainless is possible. On my packs it will be strictly copper due to high peak current demands.
ReplyDeleteYou have a point there Mike :). You are right about the cable I use (#4). You will see a big difference if you use thicker cable though. I welded two 0.007 stainless steel strips on top of each other(0.014) to steel and it was unbreakable.
ReplyDeleteYou have to download the qwk file to your computer before trying to open it with GC-Prevue.
I used GC_P version 11.3.2. Tried to open them from my desktop. Got a compatibility error. I was thinking of using silver plated wire so I could keep it at around #4 ga.
ReplyDeleteThe latest version GC-prevue is 17.4.2.
ReplyDeleteOoops! I blew that! Now the latest is 18.1.2. I was way behind. I measured the distances and it worked out great anyway. Thanks Fritz.
ReplyDeleteHi Fritz,
ReplyDeleteCan you ship a Mosfet board to the UK? Cheers..
Matthew, send me an email with your address and I'll work out how much shipping will be.
ReplyDeletehow come you did not use a IRF1324PBF instead of the irfp2907 mosfet they have a lower rds on and higher current rating as we dont need the 75 as most caps cant handle more than 20v surge and they are rated to 24v
ReplyDeleteMaximum Continuous Drain Current - 209A Maximum Drain Source Resistance - 0.0045Ω
Maximum Continuous Drain Current 353A
Maximum Drain Source Resistance 0.0015Ω
Well Jonny, your capacitors are disconnected at the time of the surge and the free wheeling diodes in your mosfets will have to handle the back emf. Those low voltage mosfets will blow with the first weld.
ReplyDeletefair enough i did not really tink of that,but would there be enough inductance to cause a problem with back emf?
ReplyDeletea few high current scotty diodes reverse biased across the fets would sort it out wouldent it?
im just looking to save costs on the fets for the power board as i can get them local cheaply.
Yes the inductance in your wires will be enough to destroy your mosfets. Schottky diodes will cause ringing and depending on their speed and voltage will probably not stop the back emf before it reach 60V. It will protect the mosfets used in this project(75v) but will not work with the low voltage mosfets in question.
ReplyDeleteSchottky diodes connected reversed based over your Mosfet will not work.
You will have to connect the anodes of the diodes to the drains of your mosfets and the the cathodes to the positive of your capacitors. This will redirect the high voltages into your capacitors, causing some ringing but will protect your mosfets by keeping the back emf away from your mosfets
Fritz, I purchased a pair of PCB within the last the month. Right now I'm trying to drill and tap the heat sinks for the MOSFET board. I've printed the DRILLandEDGE.gwk file. The file does not show hole locations (for the heat sink) that match up with the holes already drilled in the PCB. In fact, it shows no holes at all for the heat sink but the rest of the board is there. Do you have an updated file you could share?
ReplyDeleteFellow, there are three rows of dots on the board. Each row has 18 dots. Every 3 dots are the three legs of a Mosfet. The middle leg of each mosfet is the exact point where you need to drill. Work out exactly how high on your heatsink you need to drill and draw a line. Print the DRILLand EDGE.gwk using GC-Prevue, place the paper on your heatsink, line the dots up with the line you had drawn preveously and punch every middle dot of each Mosfet. Drill and tap.
ReplyDeleteAlso make sure that you have the latest version of GC-Prevue and BOARD1:1 is selected before printing.
ReplyDelete