Sherlock Ohms: The Case of the Common Ground

You have probably heard the old (erroneous) adage, "Ground is ground the world around." That might have been true prior to the advent of electronics, but it certainly isn't so anymore. Even in the vacuum tube days it wasn't so. Once frequencies get high enough that reactance rivals resistance for dominance, you can forget about simple grounding concepts for anything other than providing a measure of safety against electrical shock. This latest installment of EDN's Sherlock Ohms series is an account by John Lombard on his experience in, "Looking for Common Ground." He begins, "The term 'ground' should be used more carefully. In our equipment, we distinguish between ground and DC common for good reason. Ground refers to chassis or safety ground to take errant AC voltage to ground instead of through an operator's body..."

Posted September 19, 2013

LadyBug LB5954L Power Sensor with LAN Option - RF Cafe

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a lady's voice announced "You've Got Mail" when a new message arrived...