on today's installment of parts that terrify me:
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on today's installment of parts that terrify me:
I don't actually know much about this LED, but it's certainly a very strong, possibly ultra low wavelength UV led. The incredibly clear cover-glass and the fact that the dies are water-cooled give off an eerie vibe.
I’m actually scared of figuring out the output power and wavelength by hooking it up to a lab supply. Anyone who knows what specs this could have? What part no it could be?
@janamarie Here a similar-looking UV LED is mentioned:
https://reprap.org/forum/read.php?245,621163,623318#msg-623318 -
@janamarie If you can get it to me, I could run it on my spectrometer at low power (just enough to get an emission line) to find the center wavelength, assuming it's >200 nm. I have a UV-VIS-NIR spectrometer and laser-rated goggles that are OD 5+ from 190 to 400 nm so combining them with skin protection I'm not worried about whatever UV it might generate.
But I'm based in the US and the closest I am likely to be to you in the near future is Bochum in a couple weeks which is still the wrong end of the country, so I would assume you can find a spectrometer closer to you than that.
I don't think there is a good way to figure out the max safe power level without any part number or ratings though, since the upper limit is usually thermal and you don't have any easy way to measure the die temperature (or even know what the max temp it can tolerate *is*). You'd probably be best off slowly cranking it up while looking for thermally induced wavelength shifts and stopping when it moves "too much" or power starts to decrease, then de-rating by a bit from that cliff
@azonenberg ooh, thank you for your offer!! I will think about it, but you’re probably right that the logistics would be complicated. Bochum is not too far away, but you surely will not have the spectrometer on hand then? Shipping it back would be a huge pain.
Re power level: you’re completely right, it’s not really possible to get all characteristics without destroying it. I would have done something similar to what you proposed. Crank the power up, plot the curve, monitor the temperatures (case and water flow), figure out where the curve flattens out and use that as set-point estimation. That wouldn’t really give me a maximum power, but a somewhat safe operating point. A shame I don’t have a part number
Thanks for the explanations!
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@janamarie Here a similar-looking UV LED is mentioned:
https://reprap.org/forum/read.php?245,621163,623318#msg-623318@Mecrisp oooh!! The die configuration is exactly the same
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@azonenberg ooh, thank you for your offer!! I will think about it, but you’re probably right that the logistics would be complicated. Bochum is not too far away, but you surely will not have the spectrometer on hand then? Shipping it back would be a huge pain.
Re power level: you’re completely right, it’s not really possible to get all characteristics without destroying it. I would have done something similar to what you proposed. Crank the power up, plot the curve, monitor the temperatures (case and water flow), figure out where the curve flattens out and use that as set-point estimation. That wouldn’t really give me a maximum power, but a somewhat safe operating point. A shame I don’t have a part number
Thanks for the explanations!
@janamarie It's a little USB powered spectrometer, if you're able to give me some level of commitment that it will get used I can probably install the drivers on my laptop and shove it in my suitcase.
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@janamarie It's a little USB powered spectrometer, if you're able to give me some level of commitment that it will get used I can probably install the drivers on my laptop and shove it in my suitcase.
@janamarie (you'd have to provide some way to power it as I won't be able to bring a lab supply with me, too big/heavy)
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@janamarie It's a little USB powered spectrometer, if you're able to give me some level of commitment that it will get used I can probably install the drivers on my laptop and shove it in my suitcase.
@azonenberg ooh, I will think about it and come back to you!! Thanks
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@janamarie (you'd have to provide some way to power it as I won't be able to bring a lab supply with me, too big/heavy)
@janamarie It would be cool to meet another cool German nerd either way... right now possible options are evening of Saturday March 21, any time Sunday the 22nd, and Monday the 23rd before about lunchtime.
I have several other possible meetups I'm trying to pack into Sunday (none actually scheduled yet) but don't have anything lined up for Sat/Mon right now
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on today's installment of parts that terrify me:
I don't actually know much about this LED, but it's certainly a very strong, possibly ultra low wavelength UV led. The incredibly clear cover-glass and the fact that the dies are water-cooled give off an eerie vibe.
I’m actually scared of figuring out the output power and wavelength by hooking it up to a lab supply. Anyone who knows what specs this could have? What part no it could be?
@janamarie find a supply that supports very low current, low enough that even at 100% efficiency UV-C wouldn't hurt you.
at this low current the LED will be very close to it's photon energy / unit charge so voltage is colour after appropriate conversion (e·U = h·c/ where e=electron charge, U = LED voltage, h = planck constant, wavelength) -
@janamarie find a supply that supports very low current, low enough that even at 100% efficiency UV-C wouldn't hurt you.
at this low current the LED will be very close to it's photon energy / unit charge so voltage is colour after appropriate conversion (e·U = h·c/ where e=electron charge, U = LED voltage, h = planck constant, wavelength)@janamarie oh, and to spell out what I implied: run the LED with this extremely low current limit, let the voltage go
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@janamarie oh, and to spell out what I implied: run the LED with this extremely low current limit, let the voltage go
@janamarie this is a variation of a "Gymnasium"(DE) physics experiment that shows light is quantised btw: when it's already shown that electric current is quantised and light of a specific colour "can't" be produced with current below some voltage, it follows that light is also quantised.
(and I'm putting "can't" in quotation marks here since incandescent lamps can do that) -
@Mecrisp oooh!! The die configuration is exactly the same
@janamarie Could you add a photo of the electrical connection of the module? It seems as if the power LED array is accompanied by either a photo diode for power or reflection monitoring, or maybe a small, possibly visible wavelength LED for alignment/indication. This would require at least three separate connections.
You could shine bright sunlight or your handy EPROM eraser into the block and measure the voltages across the pins to get hints.
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@janamarie Could you add a photo of the electrical connection of the module? It seems as if the power LED array is accompanied by either a photo diode for power or reflection monitoring, or maybe a small, possibly visible wavelength LED for alignment/indication. This would require at least three separate connections.
You could shine bright sunlight or your handy EPROM eraser into the block and measure the voltages across the pins to get hints.
@janamarie This might help determining the pinout:
https://www.lasersam.org/sam/laserdio.htm#diodct1 -
@janamarie Could you add a photo of the electrical connection of the module? It seems as if the power LED array is accompanied by either a photo diode for power or reflection monitoring, or maybe a small, possibly visible wavelength LED for alignment/indication. This would require at least three separate connections.
You could shine bright sunlight or your handy EPROM eraser into the block and measure the voltages across the pins to get hints.
@Mecrisp all electrical connections are visible in the image, see the white ceramic plate? It cuts the casing in two, both halves are a terminal
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@janamarie It would be cool to meet another cool German nerd either way... right now possible options are evening of Saturday March 21, any time Sunday the 22nd, and Monday the 23rd before about lunchtime.
I have several other possible meetups I'm trying to pack into Sunday (none actually scheduled yet) but don't have anything lined up for Sat/Mon right now
@azonenberg @janamarie
I guess you'll see me at embo++ then? -
@Mecrisp all electrical connections are visible in the image, see the white ceramic plate? It cuts the casing in two, both halves are a terminal
@janamarie Thanks! With your hint, I see it. Two connections, then? Maybe the extra die in the corner serves to safely dissipate electrostatics?
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@janamarie Thanks! With your hint, I see it. Two connections, then? Maybe the extra die in the corner serves to safely dissipate electrostatics?
@Mecrisp yea, I would think so
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@janamarie Thanks! With your hint, I see it. Two connections, then? Maybe the extra die in the corner serves to safely dissipate electrostatics?
@janamarie If the extra dot in the corner is a plain simple silicon diode, you could excite it using a red laser pointer.
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@azonenberg @janamarie
I guess you'll see me at embo++ then?@PeterSommerlad @janamarie wrong conference I'm speaking at https://harris2026.mpi-sp.org/
But if you're in the area and want to say hi, by all means
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@janamarie If the extra dot in the corner is a plain simple silicon diode, you could excite it using a red laser pointer.
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@janamarie If the extra dot in the corner is a plain simple silicon diode, you could excite it using a red laser pointer.
@Mecrisp ooh, will try that in a bit
