Audio as a diagnostic helper
Posted: Sun Mar 06, 2011 12:25 pm
I've been going on about this for awhile, so I thought it'd be good to show people what I'm using. The idea here is to use each kind of thing for what it does best, and this includes the human as part of the overall system. With not much practice, your hearing can tell you a lot, and it's effortless, you can listen while looking at something else, for example. Feedback is more or less instant, and humans can hear correlations easily (stereo imaging) that would otherwise take a bunch of signal processing to detect numerically. So I have this in the loop on the way to the data acquisition stuff, for instant realtime feedback as I twiddle things on the fusor.
This is just a cheapo Radio Shack audio amp, really the guts of a car stereo, but has the nice switching etc so I can use multiple sources and switch around. All I did was make it a rack mount, using some oval speakers filched from a dumpster TV set, and an old rack panel I had laying around. Just milled it out for things, and made a shelf to hold the little amp in there. I have "tape out" on the front panel, as well as a couple of inputs for things where I might not want to crawl under there to hook up for a quick test.
I've got the linear signal out from the neutron detectors going in there now, and you can tell quite a lot counters will miss. For one thing, the pulses aren't all the same height, they are taller for "double hits" as well as wider, so you get more bass when bursting is occurring -- where a counter would simply toss that information away. Not to mention, you can tell quickly if you're just picking up EMI or it's real signal when there is some arcing on the main HV.
The big amp above that is for driving things like X ray transformers, and is used with an arbitrary waveform generator to make interesting wave shapes -- you don't need 1.5 kW for listening!
This is just a cheapo Radio Shack audio amp, really the guts of a car stereo, but has the nice switching etc so I can use multiple sources and switch around. All I did was make it a rack mount, using some oval speakers filched from a dumpster TV set, and an old rack panel I had laying around. Just milled it out for things, and made a shelf to hold the little amp in there. I have "tape out" on the front panel, as well as a couple of inputs for things where I might not want to crawl under there to hook up for a quick test.
I've got the linear signal out from the neutron detectors going in there now, and you can tell quite a lot counters will miss. For one thing, the pulses aren't all the same height, they are taller for "double hits" as well as wider, so you get more bass when bursting is occurring -- where a counter would simply toss that information away. Not to mention, you can tell quickly if you're just picking up EMI or it's real signal when there is some arcing on the main HV.
The big amp above that is for driving things like X ray transformers, and is used with an arbitrary waveform generator to make interesting wave shapes -- you don't need 1.5 kW for listening!