On Sat, Jun 28, 2014 at 6:30 PM, Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx> wrote: > I've seen this diagram on Internet (see image). > Thoughts? This is the standard wiring diagram for a system like this. You can clearly see that it is composed three distinct items: 1. The heater (box and heating elements) 2. The controller (including one or more temperature sensors) 3. A solid-state relay. It is difficult to tell if you are asking for someone to provide all three parts or just the controller. I will point out that the heater itself at the size you are asking will almost certainly represent the greatest cost of materials unless they can be sourced from scrap. I imagine that the cost of shipping such a device could approach (or even exceed) the cost of materials. There is a fourth item somewhat hidden in here: The software that allows the user to develop the temperature profile. Implementing a PID loop to maintain a constant temperature on a microcontroller is a trivial task. Developing software which will allow the user to edit a temperature profile is very much a non-trivial task. -p.