Computer interfacing

For posts specifically relating to fusor design, construction, and operation.
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Re: Computer interfacing

Post by SkyPuppy » Tue Aug 24, 2010 11:04 pm

Is there any way to turn these into optically isolated circuits? How would one change varying voltage, for example, into something that you could connect optically? I'm way out of my experience here.

Tyler Christensen
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Re: Computer interfacing

Post by Tyler Christensen » Tue Aug 24, 2010 11:36 pm

There wouldn't be a reliable way to optically couple the analog data (you could, but you would lose significant accuracy), however you could take a number of approaches at coupling a digital stream. One method could be to run the analog data through an ADC, couple this digital datastream optically to the microcontroller or data acquisition device, then decode the digital stream in software. Alternatively, you could have a microcontroller that is sacrificial in the case of a fault and then optically couple a serial datastream to the computer that is doing analysis and logging on the data. This would protect the computer, but not the data acquisition unit.

But ultimately, even if it is optically coupled, you still need to properly shield microcontrollers and computers. These sorts of devices can be destroyed by a nearby arc or discharge even without being connected to the same circuit. Proper isolated grounded chassis and shielded cables leading to appropriate non-looped grounds is the only sure way to protect stuff even if it's not directly connected to the fusor, just nearby.


Re: Computer interfacing

Post by walter_b_marvin » Mon Sep 13, 2010 1:51 am

Full Linux boxes with wireless and ethernet are selling for under $100. Some of these have up to 7 RS232 inputs, for say, a microcontroller board with A/D capability. This gives you

1) Remote Monitoring
2) Positive remote control

I should be able to write a C# gui application to read all meters, and apply voltages, while sitting safely behind a wire saftey cage. My PC application will talk to the LInux box, witch in turn will drive up to 7 controllers, each of which might have 2 or three functions. At least that is my approach.


Re: Computer interfacing

Post by walter_b_marvin » Wed Sep 15, 2010 10:21 pm

I one converts rs232 to an optical level, transmission loss on the optical line is irrelivant

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