Monday, October 29, 2012

Reverse-engineering and testing an x-ray filament supply

I bought a set of x-ray equipment on eBay, which included an x-ray head unit, 50KV supply, and filament power supply. The filament supply has a 25-pin connector, and no data or markings on the case or board. I spent some time reverse-engineering the circuit, and determined how it should be connected to make an emission-controlled x-ray system. I tested the whole thing, and it appears to be working as intended at 50KV / 1 mA.  The head unit produces a beam of about 25 degrees total angle.


  1. Wish I had enough money to buy equipment and build stuff like this.

  2. Wish i was half as smart as this guy.

  3. In the first half of the video (e.g. say at 2 mins), what's the blue dev. board in the top-right corner (with that blue sticker on it)? Looks like a full motherboard?

    Neat way of controlling the emission current - I wonder if this principle could be adapted for other tubes such as magnetrons to regulate the output.

  4. Lindsay, the board is a terasIC DE1 dev board with an Altera Cyclone II FPGA.

    Some high power linacs with magnetrons have an autotuning circuit that either adjusts a tuning slug or some other parameter to control frequency. This matches the RF source to the linac as it is being used.