Usb Mini Fridge How Does Usb Work? Like What Parts Are Needed And How Much Money Does It Cost To Make A Usb Powered Thing?

How does usb work? like what parts are needed and how much money does it cost to make a usb powered thing? - usb mini fridge

I'm doing a project in mathematics in advertising and marketing, and I need an estimate for the cost of manufacturing the product. I think the sale of a mini-USB-powered refrigerator, but do not know how to change the price because they do not fully understand all the calculate USB and its parts. How do you think are the costs?