Mike Doughty over at PCBSmoke shared his DIY 110v temperature controlled soldering station in the project log forum:
This post shows how to build a do it yourself 110 volt soldering station. It is a step by step guide that shows how to convert a regular plug-in soldering iron into a temperature controlled unit.
It is an easy project that is inexpensive to make and requires only basic skills to build. It is made from off the shelf parts that can be obtained from online suppliers plus a few parts from a local hardware store. It is inexpensive to build plus it makes a shop tool that is on par with some commercially available units.
A thermocouple was inserted into the soldering iron at the rear of the heating element and the power cord and AC plug were replaced with a flexible multi-conductor cord and 4-pin DIN connector.
Project info at PCB Smoke site. Via the forum.
Check out the video after the break.