When I hear "equipment" I immediately think of a tool. That is, equipment is something someone uses to get some sort of job done. So "equipment" can be several different things like a carpenters tools, a police officers weapon, and a chefs cooking utensils. I don't know if it's the same word in Chinese, but in Japanese it would be 装備.
A device is similar to a tool, but it has the nuance of being electrical or mechanical in nature. Also size doesn't really matter. A device can be big or small.
I hope this helped.