1. Overview of the inverter Variable-frequency drive (VFD) is a power control device that controls the AC motor by changing the working frequency of the motor by applying variable frequency technology and microelectronic technology. The frequency converter is mainly composed
Before April Fool's Day last year, Amazon, the e-commerce site, launched a shopping button hardware, such as a "toilet paper" button attached to the toilet, which automatically issued an order for the purchase of toilet paper when pressed. This delicate hardware