A charging device for a battery pack in which universality is achieved without restrictions imposed by the charging terminal unit of the battery pack, a demand for size reduction can be met, and in which the request for safety and reliability may be met with reduction in production cost. The first lead wire is connected to one end of the electrical wire through a first connecting member. The low ambient pressure environment is provided by a vacuum tank coupled to a vacuum pump and having both the workpiece and a cold spray gun located therein. Moreover, systems are disclosed that are capable of automatically determining whether to encrypt a file based on the generated encryption rules. As there are no transformer and electrolytic capacitor, the non-isolated LED driving circuit is simplified, durable and cost-effective.