To understand how and when to apply NEC Art. 725*, you must first understand how the NEC classifies remote-control, signal, and power-limited circuits. Each classification addresses different energy ...

Accurate signal conditioning and high-resolution measurements are no longer limited to industrial or instrumentation applications. Designers of portable consumer- electronic equipment also need to ...

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 ...

Switching ac power on and off has been a challenge since Edison and others started switching power more than 125 years ago. Now, a solid-state relay (SSR) uses a patented zero-voltage crossing ...