Category: Spot welder

Spot welder

I had a lot of 10mF 6V capacitors where I didn’t had a use for. After putting them in a different place again, I decided to create a sort of spot welding machine with them. The inspiration comes from a elektor magazine where something similar is done.


The intention is that the amount of energy that is put in the capacitors is adjustable. Therefore the output power into the short-circuit will be adjustable. This is controlled by a microcontroller. I will also make a measurement on the output pins, so that sending the current to the output can be delayed after contact (to prevent sparks)


For adjusting the settings I have added a display and 3 buttons. For the display I chose an HP HDSP 2111 H5, this display is smaller than an LCD and therefore fits easily on the front panel, a disadvantage is that it can only display 8 characters.

The front panel layout I want to use:


The cap pcb:


In the enclosure:


Control pcb:


The 2 pcb’s will be mounted on top of each other:


The front pcb is not made yet.



The capacitor pcb:


Control pcb:


Display pcb: