Make a capacitor solar container spot welding machine

Does a spot welder need a microcontroller?

This spot welder, unlike many available DIY projects, doesn't need a microcontroller to work: the welding pulse is triggered using relay module and a timing capacitor. Welding current is switched with an old recycled industrial thyristor module. Pulse energy can be adjusted with a potentiometer, which changes the voltage of capacitor bank.

How do you Weld a capacitor?

Place one of the probes on the bottom metal piece & press the other probe on the top metal sheet. Some sparks will fly, after which you should see a secure weld nugget. Fully Discharge the capacitor after every weld.

Can a spot welder use a Nichicon capacitor?

Currently this spot welder uses automotive grade Nichicon capacitors. It would be a good idea to check the feasibility of using cheaper capacitors, and test if it's better to use higher voltage ratings, or higher capacity. I managed to capture oscilloscope image of the pulse with an old analog Philips PM3226 oscilloscope.

What power source does a spot welder use?

Other spot welders often use car batteries, microwave oven transformers, high-current li-po battery packs or supercapacitors as power source. All of these things seemed to be very powerful and somehow scary to me, so I decided to use an capacitor bank made of regular electrolytic capacitors.

How does a spot welder work?

It can be used to weld nickel strips to battery packs. This allows re-building battery packs for various devices, especially ones that are no longer maintained by the manufacturers. This spot welder, unlike many available DIY projects, doesn't need a microcontroller to work: the welding pulse is triggered using relay module and a timing capacitor.

How do you connect a capacitor to a plastic bottle?

2) Make a hole on the cap of the empty plastic bottle & connect the end of the wires to a 2-terminal rail connector through the cap of the bottle. 3) Connect the +ve & -ve terminal of the capacitor to the +ve & -ve probes respectively, then put the capacitor & the power within the plastic bottle & firmly secure the lid.