Skip to content

Beginner lesson 5 of 17 · 20 min Pro

The seal-in circuit in ladder logic

Keep an output on after you let go of the Start button, using the output's own feedback contact, and drop it on Stop.

Open the starter in FORGE See Pro and Student plans

The starter project is free, with no account. The video is free with an account. The lesson, quiz and checked practical are Pro.

What you build.

Keep a motor running after Start is released with the output's own feedback contact, and drop it with a normally closed Stop.

A seal-in rung while running: StartPB in parallel with a MotorRun contact, then a normally closed StopPB, driving MotorRun — The finished rung, running in FORGE.

In this lesson.

Video

A short walkthrough. Free with an account.

Lesson

Short steps, one idea each.

Quiz

A short quiz, with the reason behind every answer.

Hands-on

Build it in FORGE. Check my work tells you what to fix.