Tks. You mentioned isolation is important for safety. Can you elaborate some specific examples? As per my imagination, unless the threat has been predicted then the AC transformers are useless against sudden issues. Say, an abrupt surge will still propagate via its magnetic field before we can do anything.
Isolation is not about surges, but about preventing current from flowing in a particular path at all. In a transformer, there is no conductive (only magnetic) path from the input side to the output side. So, if you touch one or more of the low-voltage output terminals of a transformer, you can’t thereby end up part of a high-voltage circuit no matter what else you’re also touching; only experience the low voltage. This is how wall-plug low voltage power supplies work. Even the ones that are using electronic switching converters (nearly all of them today) are using a transformer to provide the isolation: the line voltage AC is converted to higher frequency AC, run through a small transformer (the higher the frequency, the smaller a transformer you need for the same power) and converted back to DC.
Tks. You mentioned isolation is important for safety. Can you elaborate some specific examples? As per my imagination, unless the threat has been predicted then the AC transformers are useless against sudden issues. Say, an abrupt surge will still propagate via its magnetic field before we can do anything.
Isolation is not about surges, but about preventing current from flowing in a particular path at all. In a transformer, there is no conductive (only magnetic) path from the input side to the output side. So, if you touch one or more of the low-voltage output terminals of a transformer, you can’t thereby end up part of a high-voltage circuit no matter what else you’re also touching; only experience the low voltage. This is how wall-plug low voltage power supplies work. Even the ones that are using electronic switching converters (nearly all of them today) are using a transformer to provide the isolation: the line voltage AC is converted to higher frequency AC, run through a small transformer (the higher the frequency, the smaller a transformer you need for the same power) and converted back to DC.
Oh, I was too focused on the system function while forgetting that safety can primarily apply to human health too :)