mosivers

Micro-channel plates are also not that easy to obtain ;-) I thought about making a scintillation detector. I did some test where I coupled the crystal to an APD but did not see any signals, probably due to the small active area of the APD. Another problem is that my crystal has some cracks and, as you pointed out, it would need to be polished but I like to keep the crystal they way it is. I found this website which sells old NaI(Tl) crystals and photomultipliers relatively cheap but you would still need a HV power supply.Regarding your questions, the CaWO4 crystal will completely absorb the UVC light but adding a shield made from transparent acrylic around the box sounds like a good idea. I did not measure the spectrum of the UVC LED but ozone is only produced for wavelengths below 240 ...

Micro-channel plates are also not that easy to obtain ;-) I thought about making a scintillation detector. I did some test where I coupled the crystal to an APD but did not see any signals, probably due to the small active area of the APD. Another problem is that my crystal has some cracks and, as you pointed out, it would need to be polished but I like to keep the crystal they way it is. I found this website which sells old NaI(Tl) crystals and photomultipliers relatively cheap but you would still need a HV power supply.Regarding your questions, the CaWO4 crystal will completely absorb the UVC light but adding a shield made from transparent acrylic around the box sounds like a good idea. I did not measure the spectrum of the UVC LED but ozone is only produced for wavelengths below 240 nm so it is probably not an issue.

That sounds like a great project. If you have multiple minerals it makes sense to put them on a rotating platform. Let me know if you make this I would really like to see it in action.

I agree that UVC light is dangerous and you should take proper safety precautions. To excite the fluorescence in CaWO4 wavelenghts below 280 nm are needed so there was no way to avoid it. As I see it during operation no LED light can get out since it is either blocked by the housing or absorbed by the crystal.Regarding the health risks of UVC please see the exempt below from the EU health agency’s safety guidelines.“UVC is strongly attenuated by chromophores in the upper epidermis (Young, 1997) and UVC-induced DNA damage in the dividing basal layer of human epidermis is not readily detected (Campbell et al, 1993; Chadwick et al, 1995) which may explain why the dose response curve for UVC erythema in human skin is very much less steep than for UVB (Diffey and Farr, 1991). It is unlikely ...

I agree that UVC light is dangerous and you should take proper safety precautions. To excite the fluorescence in CaWO4 wavelenghts below 280 nm are needed so there was no way to avoid it. As I see it during operation no LED light can get out since it is either blocked by the housing or absorbed by the crystal.Regarding the health risks of UVC please see the exempt below from the EU health agency’s safety guidelines.“UVC is strongly attenuated by chromophores in the upper epidermis (Young, 1997) and UVC-induced DNA damage in the dividing basal layer of human epidermis is not readily detected (Campbell et al, 1993; Chadwick et al, 1995) which may explain why the dose response curve for UVC erythema in human skin is very much less steep than for UVB (Diffey and Farr, 1991). It is unlikely that UVC from artificial sources presents an acute or long-term hazard to human skin. However, UVC is likely to cause acute photokeratitis… UVC exposure is unlikely to cause acute or long-term damage to the skin but can cause severe acute damage to the eye“

You might want to try different grounding schemes, is the shield connected to the ground of your power supply? Also a 1000 µF capacitor between the positive and negative leads of the power supply, in parallel to the amplifier can help to reduce noise.

Thank you, I am glad that you like the build.In my code each strip already corresponds to a different frequency band but the strips are controlled by a single data pin. The function "calcAmp()" first calculates the amplitude for each frequency band, then "lightPixels()" lights up the corresponding LEDs. If the number of LEDs per strip or number of strips is different in your design you just need to change the variables "NUM_LEDS" (total number of LEDs), "NDOTS" (LEDs per strip) and "BANDS" (number of strips). Also the order of the LEDs for each strip may need to be changed in the function "lightPixels()".

Hi there, your Sanyo also looks very cool. It is certainly possible to connect it to your mp3 player. If the amp of your Sanyo is still working you can connect the mp3 player to the radio input as I did. Otherwise you could just reuse the speakers and add another amp, e.g. a TPA2012 (https://www.adafruit.com/product/1552)

Thanks. If you are referring to the song in the video, this is actually a track by Pomplamoose.https://youtu.be/ooZR4LSuppk

I agree, it would be a shame to trash an old boombox. It is certainly possible to connect some buttons to the GPIO pins of the RPi and configure them accordingly. The buttons in my boombox were directly attached to the tape deck so unfortunately, I had to remove them.

Yes, this looks great. Please share the design or write an instructable.

Thanks for sharing your design Vincent, it will be of great help.

Your modifications seem to solve a lot of problems I am having with this build. Would you be able to attach stl files for the modified pieces? Also could you send a link for the exact type of bushings you used? A dxf file or exact dimensions for the holes in the baseplate would also be very helpful.

I have not tried any other material than microscope slides yet. If there is a plastic layer it will propably not withstand the high temperatures during soldering. It might be worth just to try.

Thanks. I am glad that you like the project. Keep me updated on your cube.

You are right a video was certainly missing. I have added one at step 9 above.

Thanks a lot for your nice feedback. I will definitely try the casting for my next project.