Elschema Symboler |top| <ESSENTIAL>

How components are linked.

You see a 24V DC power supply (rectangle labeled 24V). A stop button (NC – red, normally closed symbol). A start button (NO – green, normally open symbol). A relay coil (K1). A holding contact (K1 – NO contact in parallel with the start button). elschema symboler

Today, you rarely draw symbols by hand. Here are standard tools that include complete elschema symboler libraries: How components are linked

A lamp symbol (circle with X) labeled H1. It is wired across the relay coil. Interpretation: H1 is ON when K1 is ON. elschema symboler

A line with a "gate" that can be open or closed.