Tuesday, November 24, 2015


Ver 2.5 processors are available. By changing out two zener diodes and adding a resistor to pin 15 on the control board will increase the weld energy from 600Ws to 800Ws. VER 2.5 Processor can work with 20V capacitors by removing the resistor on Pin 15 but the diodes should not be replaced until 25V capacitors are installed. UPDATE:  JANUARY 5th 2016: 25V computer grade capacitors are hard to get at the moment. A  Chinese company manufactured a couple of 1Farad 25VCapacitors for me. These Capacitors are heavy duty and very well built. I tested them and are great,  1.070 Farad with a 0.001 ESR. I can get them for a special price of $45 each. The shipping is expensive though and can only be shipped with DHL for $104. Contact me for more information to order these capacitors.


  1. When will the PCB's and processors be available? I'm interested in building one for myself.
    victor giraud

  2. Hi Fritz, I purchased your boards and chip quite a while ago and due to infirmity have only just got around to looking at building this beast. You mention a site to purchase computer grade 25V Caps. Could you please send me the link? Regards John Zonnevylle

  3. I'm currently in the process of building this welder and plan on using 11 capacitors in parallel to equal the 3 farad. I've acquired various size 25v computer grade capacitors off ebay. Not from the seller that the link in the BOM Fritz has in the control pcb manual folder but from other sellers.

    Also, I have found the MOSFET IRFP2907PBF for $2.69 each from AVNET. Is AVNET a reliable source for parts? Has anyone ordered from them before?


    1. Jeff, That's a good price, never bought from them before but you will probably pay shipping and tax on it. I just placed an order from China for $2.50 each. With shipping, 20 will cost you about $2.90 each. You can get a better price if you ask them for discount and you are protected by ebay. http://www.ebay.com/itm/1pcs-IR-IRFP2907-75V-N-Channel-MOSFET-Transistor-International-Rectifier-/161393641309?hash=item2593cf875d:g:mNoAAOSwEK9T60DT#shpCntId

  4. A couple quick questions...

    I See that there is newer firmware for the proc, in the ordering page theres a listing for "control, mosfet PCB's & ver programmed 2.1 proc" have these been updated to 2.5 & just not updated the listing?

    Are those boards already populated with the required components?

    If I were to build one of these, aside from the above item -Does that include the plans? After everything is said & done, whats the approximate cost here?


  5. Bigg_D, no its still ver 2.1 processors for people that wants to build 600Ws welders. The control and mosfet boards can be purchased without the ver 2.1 processor and then purchase the ver 2.5 processor separately.
    No, the boards are not populated. The plans has a Bill of Materials and links to purchase the components.
    No, the plans are not included. The welder will cost about $450 to $500 including the boards, processor and plans. It depends on the type of capacitors, case etc though.

    1. Can the proc be flashed from the board, or does it need to be removed to be flashed?

      The caps above with the insane shipping... how many of them are required, they ever come up with some more frugal shipping, are they still available, and if so do you have any details on them you can share?

    2. No, you have to remove the processor and have a Pic programmer to do it.
      You need Three(3Farad max) 25V capacitors in Parallel to get 800Ws.
      Its expensive to ship because capacitors are in the same category as Lithium batteries and can only be shipped via DHL The cost including shipping is much lower than what you would pay in the US though.
      The company's name is Dongguan City Gonghe Electronic Co., Ltd. You can find and contact them on Alibaba.com. The person i spoke to was Mr king Liu. Here is a link http://www.alibaba.com/product-detail/electrolytic-capacitor-25v1000000uf-farad-capacitor_1969710833.html?spm=a2700.7724838.0.0.9sKWZv

  6. Hello
    Can i use 2,7v 100F capacitor in paralell 10pcs and get 100F and 27V ??

  7. Bukaj, no you cant.3 Farads max


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