How to Wire a Photoelectric Sensor to an AC Timer Relay
Learn how to connect a 24V DC photoelectric sensor to an AC timer relay using an interposing relay. Complete wiring guide with diagrams, explanations, and troubleshooting.
Bob Odhiambo
Bob Odhiambo is a Mechatronics Engineer, industrial automation specialist, and technical writer. He is the founder of (Bob Teaches Tech) and a contributor to (EEPower) and (Control.com), where he writes technical articles and industry news on industrial automation, PLC programming, robotics, power electronics, and emerging engineering technologies. His mission is to simplify complex engineering concepts through practical, hands-on content that helps students, technicians, and professionals build real-world skills.
How to Build a PLC Timer Loop Sequence
This is a full build-along tutorial that goes beyond the Bob Teaches Tech YouTube video. It covers the hardware, wiring, GX Works2 project setup, and explains each step of an automatic timer loop sequence on a Mitsubishi FX3U PLC. You'll also find 15 real-world uses, 20 common beginner mistakes, a troubleshooting guide, and over 35 frequently asked questions.
Arduino Digital I/O Explained: pinMode, digitalRead, digitalWrite
Arduino digital I/O explained: pinMode, digitalRead, and digitalWrite with a tested button-and-LED wiring and code example.
Modbus Register Types Explained: Coils, Discrete Inputs, Holding Registers
Modbus register types explained: coils, discrete inputs, holding and input registers, function codes, and addressing conventions.
How to Set Up a Modbus TCP Connection Between a PLC and SCADA
Step-by-step guide to connecting a PLC to SCADA over Modbus TCP, including port 502 setup and a troubleshooting table.
PLC Data Types Explained: BOOL, INT, REAL, and Structures
PLC data types explained: BOOL, INT, DINT, REAL, arrays, and structures-with a real scaling bug example and vendor comparison.
Mitsubishi GX Developer Timer Tutorial: PLC Programming Guide for Beginners (FX Series
In PLC programming, the control of time is an essential factor when it comes to timely control in automation. Learn how to represent timers in the Mitsubishi's MELSEC series FX-3u PLC using the GX Developer software.
PLC Timer Programming Tutorial: Mastering On‑Delay Timers (TON)
The Role of Mechatronics in Industry 4.0
How to Program a PLC in Ladder Logic
