Science/Engineering/Technical forums

Coming along very nicely -- good stuff!

I'm very much looking forward to seeing it all linked together to have a glimpse at its predictive capabilities.
Especially this prediction stuff I'd love to see in action and try myself one day!

Philipp

I'm very interested in the neural network part for prediction. What kind of training strategy are you going to use?
Please keep us posted!

Philipp

EDIT: you might find this interesting: a couple years ago I worked on a similar (commercial) project, which was a network for steel bridge monitoring ...

This is very cool stuff indeed!

Do you have any information / guesses on how it determines pulse heights? Analog preprocessing / peak holding also, or everything handled digitally?

Philipp

Hi,

the thing is - apart from getting rid of the preamp, I did not make any changes to the circuit. Given the intrinsic problems of the design, I'd say it works remarkable well (for my practical requirements, I can do away with the noise by just letting it run longer).

Here's another one I did the ...

I finally got a chance to do some cross-checking between the two heads Doug sent me. I took spectra of the Cs-137 check source and small radium watch hands.

Here's the raw data (only first and last channel removed from displayed dataset):

radium_small.jpg
radium_big.jpg
cs_small.jpg
cs_big ...

Doug sent me (thanks again!) some Na:I heads among other stuff, and I finally got around to try the smaller one of these. (I still need to put a BNC plug on the bigger one before I can wire it into my MCA.)
I didn't change any settings on the MCA, just replaced the BC-412 by the Na:I and wondered ...

Cool!

Thanks for the clarification on functionality, now it makes sense (even) to me!

I'm looking forward to the first spectra!

Keep us updated,
Philipp

Cool stuff!!

I have some questions about your schematic, though: which type of flip-flop are you using (I didn't find a datasheet for the SN74LVC1G75, as shown in your scan)? Also, is the "P"-input you're using the data- or preset input?

I think I understand everything up to the transistor pair ...

Wow - those are quite a bunch of images ;)

You're of course right with the differentiator -- I was posting before thinking, sorry.

Hmm, I wasn't aware of the fact that pulse-pileup could cause you much trouble with safe-to-sit-next-to sources anyway.
But since this doesn't seem to be the case, we ...

Hi Doug,

nice video, thanks!

Yeah, I thought of only using the internal AD's S/H, too. But you would necessarily have some jitter due to interrupt latency (you still need to tell the PIC when to switch to "hold"). I guess it's worth a try to see whether those are acceptable.
Still, the dsPIC I'm ...