Battery tab welder

Some years ago I needed to weld metal solder-tags onto some nickel-cadmium batteries. A nearby surplus supplier had some 120,000uF computer-grade capacitors in stock for an absurdly cheap price, so I ordered five of them. An SCR was procured from Farnell, and the welder was born…

I ended up using an L200CV linear regulator to regulate the capacitor voltage, and a 7805 to generate the gate drive for the SCR.

I built this thing about ten years ago, so all information here is provided on an as-is basis!

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