I'm building powered running strollers. Those need battery packs. Battery packs need tabs. Thus, a hack is born.
An ATXMega32U4a accepts USB control requests to configure weld attributes. I haven't had time or parts to implement a user interface with a dedicated display, and with a framework I wrote a few years ago called USBKit interfacing to manufacturer-specific USB devices is really quick and easy.
A 3D-printed foot pedal starts a state machine using TCC0 to control a big solid-state relay which switches the mains across a rewound microwave oven transformer.