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The previous tutorials featured resistors in direct current (DC) circuits wherein the voltage and current have been assumed to be of constant polarity, flow and direction. The voltage, current and ...

Calculations of power and energy are relatively straightforward when the subject is strictly dc circuits. The situation is more complex in the ac world, however. Here are the basics of watts and ...

Inductance is the link between electric circuits and magnetic fields. Voltage and current sine waves are in-phase when they peak and cross the zero axis at the same time. However, this rarely happens ...

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 ...