Power Over Ethernet Solutions

The D-Link DWL-P50 is a ready-togo
module. Ethernet in, Ethernet out,
and a choice between 12- and 5-VDC
outputs.

Powering devices over Ethernet cabling seems easy, but there’s more to it than meets the eye. In this article, Eddie Insam explains how it all works. So you’ve designed a brand new Ethernet-based device. Perhaps it’s a clock, a weather … Continue reading






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IoT Project: DIY, Net-Connected Wireless Water Heater

Serving up the current temperature involves
several computers, a Wi-Fi access point, and the
DPAC Airborne module.

Some people like to remotely start their cars when it’s cold outside. Dan Beadle took this idea one step further by Internet-enabling his mountainside retreat’s hydronics system. The innovative design enables him to warm the house well in advance of his arrival. … Continue reading






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A Real-World Look at Lighting

sdfa

Living on a granite hill during a thunderstorm gave Circuit Cellar founder Steve Ciarcia new respect for Mother Nature. In a classic 1998 article, Steve described how he worked with Circuit Cellar columnist Jeff Bachiochi on a solution to automatically … Continue reading






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Find and Eliminate Ground Loops

FIGURE 4: Ground isolator for three-prong powered appliances

Everything had been fine with my home entertainment center—comprising a TV, surround-sound amplifier, an AM/FM tuner, a ROKU, and a CD/DVD/BlueRay player—until I connected my desktop PC, which stores many of my music and video files on one of its … Continue reading






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Robots with a Vision

In M1’s IR sensor array, each LED is
fired in turn and detected reflections are latched by
the 74HC259 into an eight-bit byte.

Machine chine vision is a field of electrical engineering that’s changing how we interact with our environment, as well as the ways by which machines communicate with each other. Circuit Cellar has been publishing articles on the subject since the … Continue reading






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Wireless Remote Control of the AVMux

CiarciaCC46-AVMux

In 1994, Circuit Cellar’s founder, Steve Ciarcia, asked: “What good is having ultimate control over your virtual audio/video environment if you have to get out of your chair to change the setup?” Great question. His answer was even better: “Outfit … Continue reading






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How-To Guide for Timing Analysis

Photo 1: I used Timing Diagrammer Pro for the timing analysis of the simplified digital circuit. Note that the gray areas on the waveform denote regions of uncertainty. The red areas show a timing violation.

Although many young engineers have been taught excellent circuit design techniques, most haven’t been schooled about the importance of timing analysis. What is timing analysis? Why is timing analysis important? How do you perform timing analysis? Philip Nowe’s Circuit Cellar … Continue reading






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