well the one he worked and tested on was trash.. but that doesnt mean all versions are paper weights??
It's not about the individual device, it's about the principle of operation.
Electrical Power Types
"Real" Power measured in Watts. Results in "work" being done - a wire heats, a motor turns, a filament lights up, etc
"Reactive" Power measured in VARs (Volt-Amperes Reactive). Also called "Imaginary" power is a result of voltage and current out of phase in AC systems.
"Complex" Power measured in VAs, simply stated, is the above combined. (some math terms would make this statement more true, but not important here)
In power systems, it is usually desired to have no reactive power, only real power. That simply means that your voltage and current are in phase. Capacitors and inductors (motors) will draw the phases off. We call this power factor (PF). By improving your PF (PF correction), you can actually reduce the amount of current in a circuit, without affecting the work done. This can result in less Real power being dissipated in resistive components.
The Chinesium device in question is really doing power factor correction - but it's mostly useless in this application. Two things:
1) Industrial customers are billed for bad PF. Depending on how far off they are (huge motors, etc), they will need to add power factor correction (capacitance) to their systems. It's good practice anyway, because you can reduce the current, thus reducing heat in resistive loads, making shit last longer in general.
Residential customers are not billed for bad PF, mostly since the size of the inductive loads are relatively small, thus having pretty good PF anyway. The smart thing to do would be to add a capacitor into an inductive circuit on any given appliance, so it can be matched. In fact, it's such a good idea, I think most appliances have these anyway. A/C units, refrigerator motors, etc.
2) The capacitors in question are not matched in value to the system they are correcting, and it's operating all the time, not just when the inductive load is running.
As a small note, the LED and circuitry in the device are also always on, thus drawing Real power that you are being billed for. To be fair, it's not much, so you likely wouldn't notice in your electric bill.
Bottom line: the principle is sound, but the execution would have to be matched to your electric loads. It is a valid solution to a very real problem; just not a problem you likely have.
