Editor's Note: Here's another take on the transformerless AC line power supply, which finds use in some well-insulated, low-power devices. Our technical reviewer pointed out that C ac should be an ...

Here are 4 simple 12V power supply circuits with output voltages around 12V. First power supply circuit is built with BD139, one zener diode and a few passive components. Each of the schematic is very ...

If the power source is a listed Class 2 transformer or listed Class 2 power supply — or it’s in listed equipment marked to identify the Class 2 power source — you’ve got a Class 2 circuit between the ...

Advanced power packages are breaking barriers that affect dc, ac and thermal performance in switch-mode power supply circuits for a broad range of applications. Lily Hsiu-shih Chu, Evaluation Engineer ...

Switch-mode power supplies (SMPS) continue to replace linear-regulator types in a host of applications. As the need for more efficient electronics accelerates and as a result of their size, weight, ...

The distinction between a branch circuit and a feeder can be a source of confusion for many Code users. The first step in eliminating this confusion is to understand that the NEC defines a branch ...

A power supply for electronic devices. Also called an "AC adapter" or "charger," power adapters plug into a wall outlet and convert AC to a single DC voltage. Computers use multiple DC voltages, and ...