An inexpensive multi-channel AC heater control system

A commonly-encountered problem in the experimental modeling of thermal-management solutions is the need to independently power many sources of heat. A typical telecomm circuit pack, for example, may contain a dozen or more ICs or optical components, and we would like to test cooling solutions by replacing each IC with an independently-computer-controlled resistive heater. This could be accomplished using multiple DC power supplies, but this approach is overly precise, bulky, and, worst of all, expensive: at least several hundred dollars per channel. We have built a much more economical system, using triac-based AC lamp dimmer modules originally intended for hobby or household use. Controlled by an Arduino Due processor board and a Labview program, this approach costs less than $100 per channel.