You’ve probably noticed that everywhere you go — the doctor’s office, hotels, or retail shops, there are tiny PCs everywhere.

And when you work with one, you have to know that any part of the circuit can be at mains voltage. Now read on to see why! A transformerless power supply (TPS) is basically just a voltage divider ...

Power supplies known as "switching" power supplies are commonly used. Their name is derived from the type of circuit used to change the voltage. For more details, see transformer. See power adapter.