The saved illustration on this page shows a Raspberry Pi connected to a four-channel relay board, alongside a mains plug and lamp. Although the original page address refers to MOSFETs and LED lights, the pictured hardware is a relay-board example. The address is retained so existing references still reach the same image.
Identify What Is Shown
The computer appears at the left, with small connections running toward the relay board’s control-header area. The board contains four blue relay housings and a row of load terminals. A separate red/black path is drawn between a terminal pair, the plug and the lamp.
Separate The Reference From A Build Design
A relay board and a MOSFET switching circuit are different hardware choices. Keep the proposed load type and voltage explicit when selecting a more complete reference.
The illustration includes a mains-powered lamp, plug and relay-board connections.
Record The Missing Source Information
Record the exact computer and interface-board models, the board manufacturer’s schematic/manual, load specification and intended control behaviour. Check the official Raspberry Pi hardware documentation for the applicable GPIO information.
Keep the source and component information in the decision log. The two-location switch reference provides another lighting example.
Reference guide expanded October 20, 2026. Original publication date and archived references retained.