Day: September 9, 2026

Relay Coil Voltage Explained: How to Read, Choose and Match It

Relay Coil Voltage Explained: What the Number on the Case Means (and How to Match It) A relay case carries two voltages: “24 VDC” and “250 VAC 10 A.” The first feeds the relay; the second is what it switches. Mixing them up is the most common relay mistake in the field, and it ends in a burned […]

Solid State Relay Troubleshooting: Is It the SSR or the Circuit?

Solid State Relay Troubleshooting: Is It the SSR or the Circuit? A solid state relay fails on a different physics than the mechanical relay it replaced. Test it with mechanical-relay habits and it will mislead you. Its semiconductor output leaks current when off, can look dead to one multimeter and fine to another, and fails […]

Photoelectric Sensor Wiring Diagram: 3-Wire, 4-Wire and Through-Beam Sensors

Photoelectric Sensor Wiring Diagram: 3-Wire, 4-Wire and Through-Beam Types (Light-On vs Dark-On Explained) If you’ve ever stood in front of a machine with a dead photoeye, holding a replacement that has more wires than the old one, this guide is for you. Photoelectric sensor wiring looks intimidating because the same three or four wire colors […]

Proximity Sensor vs Photoelectric Sensor: Let Material, Gap, and Output Decide

Proximity Sensor vs Photoelectric Sensor: Let Material, Gap, and Output Decide Ask ten automation suppliers which sensor is “better” (proximity sensor vs photoelectric sensor), and you will get ten confident, contradictory answers. Ask the machine instead, and the argument mostly disappears. A 5 m photoelectric beam is not better than a 5 mm inductive unit; […]