Open Source Induction Furnace Continued

The open source induction furnace project discussed previously is moving forward. We are currently evaluating bids, as you can see at the induction furnace project management site. This marks a point in our organizational history where we are beginning to outsource work, consistent with the proposed open source development pipeline process. Outsourcing is an industry standard for mainstream enterprise, but it can also be useful for scaling open source economic development. In particular, it appears that we found bidders fully capable of handling the project, including possibility of building the actual system. Read the bidding negotiations at the project management site for details.

In its limit, this type of outsourcing process can be an effective route towards open-sourcing the entire economy. All it takes is an organized and funded effort. The technical skill is available, but conversion of technology into open source form requires the nurturing hand of many technologically-literate generalists.

The concept for the OS induction furnace is:

The concept embodies a universal power source for induction melting and heating. The founding principle is scalable, modular design in the nature of the open source technology pattern language. Thus, you can use any power source, build a furnace of any size, and melt any metal of choice. The modularity allows you to understand the complex device, as functions are broken down into modules. Note that we’re considering the Arduino open source microcontroller in the concept, which would be an interesting addition to Arduino’s wide range of applications. Together, we can recast new civilization from scrap metal.

The wiki pages for the open source induction furnace project are here. Here is the latest communication from the bidding negotiations to illustrate the development process and the technical points being discussed.

Dear Smartknight,

More questions for you.

1. What melt rate in kg scrap steel/hour can we expect with a 20 kW system? 50 kW system? We need to decide and select the appropriate power level for the design.

2. Is the Arduino controller a workable option, from the practical perspective? Do we even need a microcontroller of some sort? I suggest using one with hopes that it can handle frequency and power selection, or any logic involved in melting.

3. Can the frequency be selected in such a system?

4. What is the approximate materials cost for building the 50 kW power module?

5. What is the approximate materials cost for building the coil with water cooling?

6. What is the approximate materials cost for building the furnace chamber (vessel, etc)?

7. How do you suggest controlling the power level for a given power source (assume a tractor-driven power generator like this – )

Please comment on the following suggested design. A picture is attached. The concept focuses on a modular design, such that it is easy to troubleshoot, fix, and modify. The concept focuses on the ability to insert additional power-handling modules (IGBT?) into the power module, as needed. This also means that one could insert additional power-handling module drivers, as needed.

Even though you will design a 20 or 50 kw system, the system should be designed with the above in mind – or that one can modify the power of the system readily by inserting additional power elements, if one wants to build a smaller or bigger system.

Here are some explicit details. Each intersection means that there is some kind of readily-disconnectable connector, such as screw-down terminals, USB plug, other standard plug, etc.

1. Control computer – use a laptop for running realtime or stored programs to the the controller. Suggested method of connection to Arduino is USB.
2. Control module – contains microcontroller and 3 key displays – current, voltage, and frequency. It also contains the drivers for the power-handling elements.
3. Power module – main feature is that it’s designed such that it can be adapted for higher power as discussed.
4. Power source – power generator, connect it with screw-down terminals.
5. Water connection – quick connect to water source

In summary, the concept is to design and build a universal power source for induction furnaces, consistent with OSE Specifications ( ):

1. Frequency selection allows melting of different configurations and metals.
2. Plug-in induction coils allow the power source to be used in many different melt purposes and configurations, such as scrap melting or heat treatment for machining
3. Scalability in power allows the system to be used on many different scales, from desktop to industrial.
4. Computer control allows different heating logics to be applied.
5. The system is compatible with any power source.
6. If the parts are interchangeable, they are easy to maintain, fix, and modify.

These 6 conceptual points help to clarify the general direction of the project. Please let me know if you could do the above, how you suggest doing it, or what parts are impractical.



  1. Darren Vandervort

    Comments on your explicit details…

    Control computer – The Arduino is an admirable venture, but over kill for what this is. If the control loop is an order of magnitude more than what I think it is the cheapest controller will still be up to task. USB might be a bad choice for this. Due to distance limitation of the interface(I don’t think someone would bring a laptop out to wherever this furnace is), also electrical isolation is problematic. CAN interface might be a suitable substitute.

    Control module- I would put the drivers in the power block. Could be personal preference but I would rather have a tiny bit of digital in the power block then have any power in the digital block. It also increases the modularity of the power block for different technologies.

    Power module- A bit higher power then I am experienced with, but it might still fall in the fet domain rather then igbt.

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