Collaborate Disseminate
Here’s a question for you: when your PCB has a ground plane layer, where do return signals flow? It seems like a trick question, but as [Kristof Mulier] explains, there’s …read more Continue reading Proper Routing Makes for Many Happy Return Paths
Spare a moment’s pity for the process engineer, whose job it is to keep industrial automation running no matter what. These poor souls seem to be forever on call, fielding …read more Continue reading Simple Circuit Keeps Process Control Loops in Tune
A problem which beset early telephone engineers was that as the length of their lines increased, so did the distortion of whatever signal they wanted to transmit. This was corrected …read more Continue reading Current Loop Extends Wired Microphones Past 1 Km
Buried deep within all UNIX-based operating systems are vestiges of the earliest days of computing, when “hardware” more often than not meant actual mechanical devices with cams and levers and pulleys and grease. But just because UNIX, and by extension Linux, once supported mechanical terminals doesn’t mean that getting a …read more
How do you get the kids interested in old technology? By connecting it to a phone, obviously. Those kids and their phones. When [Marek] got his hands on an old-school teletype, he hooked it up to a GSM network, with all the bells and whistles including a 40mA current loop …read more
“They don’t build ’em like they used to.” There’s plenty of truth to that old saw, especially when a switch-mode power supply from the 1940s still works with its original parts. But when said power supply is about the size of a smallish toddler and twice as heavy, building them like the old days isn’t everything it’s cracked up to be.
The power supply that [Ken Shirriff] dives into comes from an ongoing restoration of a vintage teletype we covered recently. In that post we noted the “mysterious blue glow” of the tubes in the power supply, which [Ken] decided …read more
The I/O capabilities built into most microcontrollers make it easy to measure the analog world. Say you want to build a data logger for temperature. All you need to do is get some kind of sensor that has a linear voltage output that represents the temperature range you need to monitor — zero to five volts representing 0° to 100°C, perhaps. Hook the sensor up to and analog input, whip up a little code, and you’re done. Easy stuff.
Now put a twist on it: you need to mount the sensor far from the microcontroller. The longer your wires, the …read more
