We’ve seen our share of blinking light projects around here; most are fairly straightforward small projects, but this entry to the 2025 One Hertz Challenge is the polar opposite of that approach.

Ladder logic uses switch or relay contacts to implement Boolean expressions. In years past, ladder logic was made possible with discrete relays and was sometimes termed “relay logic.” Today most ...

A single-coil latching relay is a relay with memory, usually with a magnetic structure that provides two stable positions for the armature that holds the movable contacts. A permanent magnet provides ...

When we first saw [DiPDoT’s] homebrew computer, we thought it was an Altair 8800. But, no. While it has a very familiar front panel, the working parts are all based on relays. While it ...

A programmable logic controller (PLC) is an industrial solid-state computer that monitors inputs and outputs, and makes logic-based decisions for automated processes or machines. 1. The image above is ...

Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...

EIGHTY years ago, Jevons, then professor of logic at Owens College (now the University of Manchester), built a machine which could perform logical inference by mechanical means 1. Other similar ...

Fig. 1:Regularly check the date and time on your EAS equipment. With many people installing new CAP-compliant gear, Jim Davis of Radio One Raleigh writes with an idea of what to do with your old box.