gavinj.net

I connected a 100W USB-C soldering iron to a bench supply through a 9V battery snap, looked down, and found the tip glowing orange. The iron probably died, but the resulting lesson in voltage, current limiting, USB Power Delivery, polarity, and improvised wiring was worth writing down.

I finished the first lesson in my electronics curriculum: multimeter basics. I measured a fresh AA battery, checked a cheap bench power supply, learned what the dial markings actually mean, and corrected my first wrong electronics definition.