There is a new version of the Spot Welder PCBs available. It features some pcb improvements as well as the new “AutoPulse” feature.

Improvements in Version 2.2

  • Mosfet PCB now with 2oz copper layer and wider traces which connect the high current carrying mosfet legs to the u-shaped aluminum part
  • “AutoPulse” feature, which automatically activates a pulse after a 2 second delay when both welding tips touch the nickel strip


The mosfet pcb update was done because some users who tryed welding with more than 1000A current reported that the pcb traces got damaged by the high current. Now it should be more resistant even to these very high currents.

The new “AutoPulse” feature only needs 5 small additional parts on the pcb. (470 Ohm resistor, 620 Ohm resistor, z-diode 4,3V 0,5w, 2,54mm jumper, 2 pin 2,54mm male header). Resistor R13 does not need to be populated. It was meant as a pull down resistor, but after looking close to the schematic i realised R14 + R15 already do the pull down to GND.

To activate the “AutoPulse” feature simply plug a jumper on the male 2 pin header named “Auto_Pulse” which connects the two pins.

You can also upgrade you existing Spot Welder with the “Auto Pulse” feature. Instructions how to do it are coming soon.


Pictures of the PCB V2.2 front and back:






2 thoughts on “New Spot Welder PCBs V2.2

  1. johnsachef says:

    where can i purchase a ribbon or other type of cable to extend the display ready made simply plug in as i want to mount the display remotely

    • Marc Schoenfleisch says:

      if you look on aliexpress for “2.54MM 4pin cable” or “arduino jumper wire” you will find the extension you are looking for

Leave a Reply

Your email address will not be published. Required fields are marked *