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 ...

Smart transformers are designed to help better manage power for cities, and the largest smart transformer in the world apparently just went online.

Measurement of average power in a 60Hz circuit (equivalent to V RMS × I RMS × cos(ø)) can be done by sampling the product of voltage and current and averaging. This requires four quadrant ...