... student's power and ampere meter indicationTechnology indication:1.Console system: input power 220VAC/50Hz, allowed error ±10%, power ... /0.5A (4) AC,DC output with overloading alarming system and voltage output indication (5) Power supply of students ... are controlled by teacher2.Ventilation Control: a. adopt stepless speed regulation system, steady velocity precision≤0.5% b. ventilation condition: ...