DIY Arduino Battery Spot Welder PCB Set V3.3

This is the V3.3 PCB Set.

What you get:

• The two PCBs needed to build your own spot welder
• 8 M3 nylon washers

This is the pcb only set. No other components included.

How to built it:

• Assembly instructions for the pcb set can be found here
• All pcb files, part list, Arduino code… can be found at my Github page.
• A detailed build guide for all spot welder parts can be found at the instructables

Improvements in V3.3:

• since 08.2019: 6oz copper layer with enig surface finish on the mosfet board
• new Mosfet Board design
• Much wider traces on the bottom of the pcb for the high current connection to the u-shaped aluminum part
• Mosfet gate resistors directly on the mosfet board, very close to the mosfet gate pins
• All 8 Pins of the female 8 pin header that connects the Arduino and mosfet board are now connected to each other, which eliminates contact problems.

Improvements in the V3.2:

• the Arduino Board was updated so it is now possible to mount a 3.5mm screw terminal to the input pads.
• the voltage measurement now connects directly to the 12V input pad instead of behind the schottky diode. This guarantuees a more precise voltage measurement.
• the 8 small SMAJ13A-13-F TVS diodes have been removed from the mosfet board. There is now one of these diodes on the Arduino board that protects all mosfet gates at once.

Improvements in the V3.1:

• possibility to solder 4 SMD TVS diodes in parallell on the Mosfet PCB
• enough space to solder 4 through hole TVS diodes instead of SMD diodes if no SMD diodes available
• with 4 diodes installed possible to use with car batteries up to 800CCA

Improvements in the V3:

• 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 defined delay time when both welding tips touch the nickel strip (thanks to Petr Zverina for the idea)
• 7 segment display replaced by OLED display
• potentiometer replaced by rotary encoder
• Menu system to easy adjust the low battery alarm, AutoPulse delay and short pulse time
• powered directly by car battery, no more need for extra power supply
• TVS diode integrated on the mosfet pcb, no external diodes necessary
• upgraded Mosfets to IRFB7430 (they can handle up to 1000A welding current with no problem)
• Standby feature: after 5 minutes of inactivity the Spot Welder will go to standby and the foot switch and AutoPulse will be deactivated while in standby.
• u-shaped aluminum parts is now riveted to the pcb