4 ms·

One of the things I only recently learned is modern power supply’s aren’t using the transformer to knock down “raw mains” 60hz AC. Modern switch mode PSU’s in-f

One of the things I only recently learned is modern power supply’s aren’t using the transformer to knock down “raw mains” 60hz AC. Modern switch mode PSU’s in-fact rectify the AC to DC and then chop it up at a much higher frequency. By using a higher frequency, the transformer can be much smaller and more efficient. If they were doing mains 60hz AC the transformer would be substantially larger. I forget if they also step the supply side DC voltage up too…

brandmeyer 4y ago
> I forget if they also step the supply side DC voltage up too… They do, but they don't have to. The front-end rectifier boosts the voltage up to 400-450 VDC. This way, most of the components can be optimized for a single world-wide compatible machine that is capable of rectifying 230VAC. In principle, you could squeeze out a bit of efficiency (or cost) by producing a North American market machine that was optimized for 120V and a separate machine optimized for 208/230V. In practice, supply chain simplification reduces overall per-unit costs, so just about everything is designed as a single machine for world-wide markets. Only the plugs change. For ATX, only the cord shipping in the box changes.