Understand basic circuits with diagrams.
Learn common circuit patterns used in relay control and ladder logic, including self-holding circuits, timer circuits, interlocks, and start/stop circuits.
What you can learn in this category
Basic circuits become easier to understand when you follow the signal flow step by step instead of trying to memorize every symbol at once.
Follow how an input condition turns an output on or off in simple relay and ladder circuits.
Learn how self-holding, alarm holding, reset, and start/stop circuits are built.
Understand interlocks, forward/reverse circuits, selector circuits, and other patterns that prevent unsafe operation.
First articles to read
Start here if you want to understand relay circuits and ladder-style thinking from the basics.
Start/Stop Circuit Basics
Learn the basic circuit used to start and stop equipment with push buttons.
2Self-Holding Circuit Basics
Understand how a circuit keeps an output on after a start signal.
3Press-and-Hold Circuit Basics
Learn the simplest circuit pattern before moving into self-holding logic.
4Timer Circuit Basics
Understand how timers are used to delay or switch operations.
Circuit articles
These articles cover common circuit patterns used in control panels, relay logic, and ladder diagrams.
One-Shot Circuit Basics
Learn how a circuit creates a short pulse from a change in signal state.
Safety and switchingInterlock Basics
Understand how interlocks prevent two conflicting operations from running at the same time.
Basic circuitsAlternating Operation Circuit Basics
Learn how outputs can be alternated or toggled using relay-style logic.
Basic circuitsJog Operation Circuit Basics
Understand circuits that move equipment only while a button is being pressed.
Safety and switchingUpper and Lower Limit Circuit Basics
Learn how limit signals are used to stop motion at the ends of travel.
Basic circuitsHome Return Circuit Basics
Understand the basic idea of returning equipment to a known reference position.
Timer controlFlicker Circuit Basics
Learn how timer logic can make an output blink on and off repeatedly.
Ladder logicHow to Read Ladder Diagrams
Learn how to follow contacts, coils, and signal flow in ladder diagrams.
Safety and switchingForward and Reverse Circuit Basics
Understand the basic interlock idea used when switching motor direction.
Timer controlStar-Delta Starting Circuit Basics
Learn the basic flow of star-delta motor starting and timer switching.
Basic circuitsReset Circuit Basics
Understand how reset logic clears holding circuits, alarms, and internal states.