I've had to run back home a few times to unplug the soldering iron I'd left turned on after working on projects. I've also left it running and burned out some tips. To save me from those problems recurring, I decided to make an automatic shut-off timer.
This timer has also come in handy while testing equipment and operating lights.
Step 1: Materials and Supplies
Automotive grade plug-in extension cord with light-up receptacle end
Bathroom ventilator timer (Analog or Digital)
Duplex Receptacle (Could use GFI Receptacle if desired)
Plastic 2 gang switch box
4 wire twist connectors (Marettes)
Step 2: Wiring Diagram Explained
Using the wire cutters, cut your extension cord in two pieces.
Strip the wires back at least a half inch. (enough to twist them together.)
If you have difficulty identifying the wires, use a circuit tester, find the ground, hot and neutral wires, making note of which is connects to which.
This cord was wired as industry standard. (Black hot, green ground and white neutral.)
Hot from wall goes to black on timer.
Neutral and ground from wall connect to all neutral and ground wires.
Red from timer goes to hot on outlet end and hot on receptacle.
Use twist on wire connectors, aka Marettes, to make all connections. This is so you can easily make modifications or repairs as opposed to soldering everything.
Step 3: Timer Operation
This timer can be set to four different programs.
The programs run 10 minutes, 20 minutes, 30 minutes and 60 minutes.
Power will automatically shut down unless you cycle the button to keep the power on.
If you want to shut the power off, keep cycling until all the green lights turn off and the red light turns back on.