So I've been silent on here, but not stagnant - see photos below. I'm developing the system monitor for my fusion efforts. Rather than separate voltage & current panel meters, vacuum meters, etc., I thought I'd put it all on a video overlay so it could all be on the same screen as the video of the fusion plasma. Right now it's a small 7" diagonal display, but it uses a standard composite video, so I can display it on a larger screen as desired.
The video overlay is a nice pre-made module from Decade Engineering, the BOB4. The system is driven by a BS2px from Parallax. I have a real-time clock built in (lower left on screen, live data), and a 5-counter CT505 chip that I use to pick up the counts from my gamma detectors (G1-G3) and my as-yet-to-be-built neutron counters (N1 & N2) - all lower right. I know I shouldn't get anything really over background on the gammas, but I have a bunch of tubes and I built a run of circuits for them, so why not stick a few in just for fun...
My vacuum pressure gauge (Edwards WRG) displays in the upper right (simulated at the moment, but it's just a simple ADC with a correspondence table), and the temperature of the chamber wall displays beneath that (live data).
Upper left is the all important voltage and current data (simulated at the moment). Voltage is taken into an LM358 voltage follower and an ADC through a 300M and an 50k voltage divider, with the bottom of the divider chain at +12v, to give me a swing of +12v at 0vdc and +7vdc at -30kvdc, roughly. Current is monitored on the "ground" side of the PS across a 10 ohm 50W wirewound resistor, again through an ADC.
Everything is sequentially polled by the BS2px microcontroller about 3 times per second.
All data is logged in CSV format to an 8Gig memory stick for recording runs... whenever they finally happen.
And because I am a goofball, I also added an EMIC2 text-to-speech module so the thing talks to me. It reads out the startup sequence, and will alert me as various presets are achieved - roughing pressure achieved, neutrons detected, stuff like that.
My goal is to get familiar enough with the parameters of my given setup that I can automate the sequence to achieve fusion, so I can basically flip a switch and it'll bring the initial vacuum down, switch on the diff pump at the right point, when the pressure's down to e-5 or so (whatever it turns out to be for the system) it'll tweak the D, and when the optimal pressure of D is achieved, it'll ramp the voltage and current and adjust for maximum N count.
That's the goal anyway.
For now, it's fun just building the monitor and control system.
The image on the screen is just the innards of my 2.75 conflat cross through the viewport. It's a cheap B&W camera for now, I'll use a color camera for the actual unit.
Happy to share details if anyone is interested in a similar setup.
Dave
