I am building an appliance where we have a device where we need to have a +48 V/300 W DC power rail and a +24 V/300 W DC power rail. The AC (mains) should be world-compatible (both low- and high- lines) and the DC part should be isolated from the mains (double-isolation)
I am struggling to come up with the best power distribution strategy to generate those two power rails:
- Two single-output AC/DC power supplies in series (mains-to-24 VDC) with a +24 VDC mid-point and common ground.
- One dual-output AC/DC power supply (Output 1: 48 VDC, Output 2: 24 VDC) with common ground.
- One single-output AC/DC power supply (48 VDC) with a step-down DC/DC converter (48 VDC to 24 VDC), with common ground.
Both DC power rails should not be isolated and share a common ground to avoid ground loops.
EMC, floor area, efficiency and cost are concerns (by order of priority).
What would be the best option?