HotTips-3000

Dual-pulse battery tab spot welder using repurposed and rewound microwave oven transformer and solid-state relay.

IntermediateWork in progress1,291

Things used in this project

Generic 128x64 OLED I2C

Push button

220 ohm resistor

Microwave Oven Transformer (secondary rewound with one turn 70mm^2 stranded copper wire)

Wires for AC and DC circuitry

40A solid state relay

5V USB charger (salvaged)

5 mm LED: Red

5 mm LED: Green

5x7cm perfboard

Rotary potentiometer (generic)

Resistor 220 ohm

Grounded power cord (for mains voltage)

Power Switch for mains voltage

electronics solder

Wood for Base

300 x 240 - 2mm acrylic sheet

small crews for plastic

Rubber grommet, various sizes for wire leads

Soldering iron (generic)

Cold Chisel (for cutting transformer secondary winding)

Punch (for removing transformer secondary winding)

Wire stripper

Oven or Heat source capable of 165 degrees Celsius

Drill with various bits and or hole sizer

Currently still under construction.

Please use caution while dealing with mains voltage. :-)

Parts include:

Microwave transformer (secondary rewound with single turn 70mm^2 stranded copper, coated with heat-shrink)
Wires and heatshrink (for mains voltage and DC circuitry)
Solid-state relay
40 Ampere 24-380VAC (3-30VDC input)
Arduino Pro Mini
OLED Display
Potentiometer
Pushbutton
Green and red LEDs
220 Ohm resistor x3
50mm x 70mm perfboard
5VDC 850mA switch mode USB power supply
Powercord, powerswitch, and enclosure

Will love to see if you make one!

Much inspiration gleaned from:

Masomtob, Manop & Sukondhasingha, Rawitat & Becker, Jan & Sauer, Dirk. (2017).Parametric Study of Spot Welding between Li- ion Battery Cells and Sheet Metal Connectors.Engineering Journal. 21. 457-473. 10.4186/ej.2017.21.7.457. https://www.researchgate.net/publication/322394238_Parametric_Study_of_Spot_Welding_between_Li-ion_Battery_Cells_and_Sheet_Metal_Connectors