The “best” barrel jack trick I have was accidentally discovering that my Dymo LabelWriter 400 Turbo that takes 24VDC uses exactly the same connector as the vast majority of 12VDC devices. For ...

Maybe I'm describing a unicorn device here but I have a bunch of devices that run off DC-in of various voltages, and take a barrel jack connector for power. They all have their own wall warts but ...