220V Scent Machine Pump Control: Relay, Power and Safety
The most critical power component of a scent machine is the pump: it is the actuator that atomizes the fragrance oil or pushes it into the HVAC duct. The job of the control board is to switch this pump safely and reliably from the 220–240 V AC mains. In this article we cover relay selection, the power supply, the difference between resistive and inductive loads, and mains safety. Onboard AC-DC: why you don’t want an external adapter Control boards run on low-voltage DC (typically 5 V / 3.3 V), but the pump is at mains voltage. There are two approaches: ...