Reasonable internal circuit layout arranges electronic parts in orderly distribution. It matches the inner installation size of compatible air conditioner models, with reserved mounting positions to facilitate daily disassembly and fitting operations. Standard electronic components are adopted with neat soldering workmanship. The connected circuits maintain stable conduction state and fit conventional household power supply environment for daily running matching. Interface specifications conform to the design standards of applicable units. Internal circuit parameters keep consistent coordination with other built-in parts inside the air conditioning equipment. Outer structure comes with basic protective performance to cope with normal indoor operating environment. Firmly fixed parts reduce displacement issues in long-term service conditions. Clear identification marks are set on the board surface. The overall shape and dimension fit assembly standards, bringing simple matching process during component replacement work.