Replicating a Multivibrator in Ladder Logic (Tutorial)

Understanding the Multivibrator

A multivibrator is a switching circuit that alternates between two states. One of the most popular multivibrator configurations uses a power supply, four resistors, and two each of capacitors, transistors, and LEDs. To recreate this, we will need to understand the relationship each part has with the operation of the circuit. The challenging part when working with a digital version of analog parts is that we may need multiple variables to capture the function of a single analog component. To help keep track of the purpose of any variable, its name will include the analog component it replicates.

Although it would be easy to create a multivibrator using static inputs for each component, this tutorial will go through the actual calculations used that influences the outputs (in this case would be the two LEDS) so that the timing between states can be changed. This will show the impact that any single component’s value may have on the circuit. This should produce the same result as replacing one of the actual components in the analog circuit.

Attached is the full tutorial on how to recreate the multivibrator in ladder logic.
Replicating a Multivibrator in Ladder Logic.docx (251.7 KB)