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 ...

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.

Here’s a really fascinating circuit that implements a combination lock using relays and logic gates. Even with the schematic and written explanation of how it works we’re still left somewhat in the ...

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 ...

The PuffinPLC Project is an effort to produce a Linux-based GNU Public Licensed Programmable Logic Controller (PLC). PLCs were developed in the 1960s to replace the complex electrical relay circuits ...

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.