This device is typical in control panel or automation industry.The main purpose of RECTIFIER is to convert from AC ( alternating current ) to DC ( direct current ).It common use because now in market,all control device is using DC power supply.It safe and energy efficiency.
Usually when we choose to control our machine or equipment using PLC or Electronic Device,We need DC ( direct Current ) power supply.The range common use in world wide is from 12 VDC until 24 VDC.So we use the RECTIFIER to convert from 110 VAC or 240VAC power supply to DC power supply :D
