Why Capacitive Power Supply Are Bad (electronics educational)

Capacitive Power Supplies are a dirty cheap solution to feed simple low power devices directly from Mains, but the drawbacks are way more than the benefits in many cases. In this video I'll try to show that with a practical experiment, and why they are bad wasting energy. In short, lack of isolation, low efficiency and a power factor close to zero should be the main reasons to suggest electronic engineers to avoid this typology of circuit. In this video I've tested an actual circuit, and described in details how it works and why it is so poor in efficiency and power factor. Even though they usually are used in small equiplemnts they waste energy and can be a factor when it comes to limiting CO2 emissions. At the moment I am writing this, we do not know whether the antropogenic emissions of CO2 are really an issue in relation to the global climate change, nevertheless increasing the efficiency, and in this case also the safety, of the circuits should be paramount of every electronics engineer. Educational video in Electronics.