Like many hackers, [Matthias Wandel] He likes to measure the world around him, and quantifying what happens in his home is a hobby. Therefore, when it was necessary to sense the current flowing in his house’s wires, he did what any of us would do: He built his own current sensing system.
What did you say? Any sane hacker will buy something like a Kill-a-Watt meter, maybe even a commercially available current transformer? Maybe, but then it wouldn’t be a hack, would it? [Matthias] For very practical reasons, he chose to roll his own sensor: commercial meters did not have enough response time to capture the startup spikes he was interested in seeing, and clip-on current transformers needed to separate the sheath on non-metallic cables. Most Residential wiring-doing so often violates building codes. Therefore, his sensor is just a coil with a shape suitable for the outside of the NM cable, and some filtering has been carried out to provide a clearer signal in the high noise environment of many switch-mode power supplies.
Feed into Raspberry Pi through ADC board, [Matthias]’The sensor system does a very good job of capturing the start-up surge of some tools around the workshop. This led to the interesting “circuit breaker challenge” section of the video below, where we learned what it really takes to pop a circuit breaker on a 15 amp branch circuit. Spoiler warning: a lot.
Speaking of maintaining safety at power supply current, we have already introduced some of the working principles of circuit protection. If you need a deeper understanding of circuit breakers, we also have them.
Thanks for the firmness of the tip line [Baldpower] tip.