I have always wanted to make a cabinet power strip, which can view the current (power) in real time and can be switched on and off remotely. There should be some products on the market, probably because they are niche and expensive.
Taking into account safety, the AC transformer is used to measure current, and there is basically no direct electrical connection with the power strip, which is suitable for any circuit modification.
A certain treasure search "current transformer module 5A range single-phase AC current sensor module" selected "Xinde Electronics", 1.4 yuan each. The range of 5A can basically cover a single-channel device of 1000W, which should be enough. If there are more equipment, there are a few more channels. It is not recommended to do one with high power, which will lose the detection of each electrical appliance.
The transformer is theoretically a mutual inductance of current, that is, the magnitude of the current of the wire under test senses each other, but it is more troublesome and does not allow an open circuit. So the merchant made a module with series resistance, which became the AC voltage value. The purpose of such a circuit is to collect AC voltage. However, the trouble is that the AD port of the general single-chip microcomputer collects DC voltage, which cannot be directly realized for AC collection. Moreover, the transformers are all small voltage values, and can not be rectified to DC by full bridges, so we can only find another way.
So search, there is a mature AC acquisition program, that is, the AC voltage is first added to the bias voltage to become a fluctuating value in the range of 0-vcc, and the microcontroller can collect.
First use the multisim12 simulation to walk one, and then try to find a suitable socket or something to change it, I hope it will not be unfinished.
