The idea behind Watt seems deceptively simple. By definition, one watt is the amount of work done during the current flow of one ampere in the potential of one volt. If you think about it, a watt basically refers to how much work is done by a 1V source across a 1Ω resistor. It’s easy to say, but how do you measure it in the real world? [DiodeGoneWild] There is an answer in a recent video where he opened a few wattmeters.
There are lots of practical concerns. With AC, for example, the phase of the components is important. The first 11 minutes of the video review some theory, but then the cat intervenes and we see some real hardware.
Inside the first wattmeter, he finds the same circuit that he was drawing at the beginning of the video, some practical additions such as range selection. The principle used is somewhat different from what he was drawing, but the basic principle is the same: Measure voltage and current to find energy.
We tend to be a little more cautious about the main power, but unlike some other famous YouTubers, he can’t at least push or set himself on camera.
We were amazed at the mechanical design of these meters and we also liked the Homebrew Power Meter Power Strip. So if you like theory, teardown or homebrew projects, there is something for you.
Measuring energy in RF is a completely different science. Naturally, there are many ways to measure watts and not every instrument uses the same method.