We can understand why the final design used a microcontroller, but we also think that [Alex’s] relay logic circuit is an eloquent way of doing things.

Its function is to transform the line voltage to the relay logic voltage and handle the contactor coil inrush current. Contactors with AC coils draw about 5 times rated current until the magnetic ...

Contemporary logic circuits use MOSFETs as the elements to build gates, but there are many ways to implement them. Using relays is one of them, and you can literally see how they work.

The circuit in Figure 1a operates from CMOS-logic levels, and the one in Figure 1b operates from TTL levels. After each transition, the signal must remain stable for longer than the relay’s minimum ...

The Basics of Ladder Logic Ladder logic is the basis of most control functions Ladder logic uses switch or relay contacts to implement Boolean expressions. In years past, ladder logic was made ...

In the circuit of Figure 1, the CPLD has to output a logic “1” (+5 V) to ensure that the relay is switched off.

This power-conditioning circuit for an automotive electronic control unit replaces bulky transient absorbers with an electronic switch, Q1, and an electromechanical relay with an RC timer circuit ...

Littelfuse, Inc. introduced the CPC2501M, a robust, self-actuating, normally closed solid-state relay optimized for chime ...

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.