There's no way a router in 2024 is using a big iron transformer. They're too expensive.
It'll be a switch mode power supply, where the power is rectified, converted to high-frequency AC (50-200 kHz), then sent through a certain specialized transformer.
It'll be a switch mode power supply, where the power is rectified, converted to high-frequency AC (50-200 kHz), then sent through a certain specialized transformer.