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Thread: LED Blacklights vs Flourescent Blacklights?

  1. #31
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    I just also scored a Nichia NCSU033B P33D22 that lists a flux of about 495-540mw, i was not expecting the vendor to except my offer under his auction price so i went with the led engin branded LZ1-00UV00 365 with a min rating of 800mw - 1250mw. I should have that in my paws on monday. and with the eBay cheapies they are still running fine, since i added the balancing resistors i have so far not have had any fail, next month i will buy the UV pass filter glass and make one into a mineral light for my rocks, errr minerals yeah that sounds better, dragons should not collect rocks but minerals are fair game and this should replace the crappy UVA CCFL that are normally used in computer cases.
    If you guys want me to try and collect more data i can try but i need some interest from you guys or the experiment may not be worth it.
    What other uses do you guys have in mind for these? or am i just babbling about something that others have no interest in?
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  2. #32
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    Hey Draco! Actually I find this all very interesting. I have several diodes on the way to play with but my goal is affordable DMX controlled fixtures. I wish I could figure out some guesstimate of luminescence but I suppose that is at least as much a factor of wavelength and the uv paint as much as output power. Anyway, I look forward to experimenting and appreciate you sharing your findings. Be sure to post some glowing mineral pics when you get there.

    Cheers!

    David
    "Help, help, I'm being repressed!"

  3. #33
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    I dont have any real data yet but to my peepers the one made by led engin is indeed brighter then 2 of the cheep ones combined, i am running it at 650ma and i think i can goto one amp, i need to adjust the driver to get it to that level, i have a second controller on it's way from Australia that will have the data i need, i may need to change out a current sense resistor to bring it up to 1 amp. I have found that these types of leds are more sensitive to mistakes then a standard led. I could go with a newer design but the one from jaycar is made to run on 12 volts and has a low battery shut down and that i need for camping, i should have it this week i hope. but sofar the led engin is worth the money, at the given current i think it's outputting about 300mw but my meter is not reliable at 365nm, the conversion i am using is at 400nm so there is i believe a large degree of error right now, it's most likely to be more like 400mw
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  4. #34
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    sofar i am impressed enough to order a second led engin device, now i just need to find a correct calculation for my uv sensor, this is the UV sensor https://www.adafruit.com/products/1918, the equation for UV index seem right but the one for flux does not make sense.

    "Extend your light-sensing spectrum with this analog UV sensor module. It uses a UV photodiode, which can detect the 240-370nm range of light (which covers UVB and most of UVA spectrum). The signal level from the photodiode is very small, in the nano-ampere level, so we tossed on an opamp to amplify the signal to a more manageable volt-level.

    This sensor is much simpler than our Si1145 breakout, it only does one thing and gives an analog voltage output instead of requiring a complicated I2C setup procedure. This makes it better for simple projects. It also has a 'true' UV sensor instead of a calibrated light-sensor. To use, power the sensor and op-amp by connecting V+ to 2.7-5.5VDC and GND to power ground. Then read the analog signal from the OUT pin. The output voltage is: Vo = 4.3 * Diode-Current-in-uA. So if the photo current is 1uA (9 mW/cm^2), the output voltage is 4.3V. You can also convert the voltage to UV Index by dividing the output voltage by 0.1V. So if the output voltage is 0.5V, the UV Index is about 5."

    that's from there web site and i would be grateful if some one can help me understand that formula, i think it's wrong but i dont know
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  5. #35
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    with that formula for UV index i get 43 so i am thinking i am over range
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  6. #36
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    i just posted on adafruit on there forums to help make sense of the formula, i added a reverse polarity diode to the led engin model and am going to take the same protocol that i use with laser diodes, i believe i lost one due to ESD and the led engin ones have a reverse Torrence of only 5 volts. pictures will be coming and the replacement cheapie leds are now in the states but they are the last i think i will order given the huge diffrence in the radiated flux, i am tempted to add a lens to mine buy it's a plastic one made for a visable light star and i have a concern that i will solarerise the plastic
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  7. #37
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    I've been on the fence about ordering the LED Engin diodes but they sound like they are the way to go. How would your rate them to a CFL blacklight or even a 48" fluorescent tube?

    BTW, thanks for testing these out!
    Last edited by absolom7691; 04-29-2016 at 13:37.
    If you're the smartest person in the room, then you're in the wrong room.

  8. #38
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    I am in the process of cleaning my front bed room where i have a 2 tube fixture and i am asking on adafruit's forum but for a point source light source the led engin by far is the best led to go with, one of my drivers failed but did not kill the diode, i missed a solder connection of the drive ic and destroyed a 2n3904 and the main
    FZT1151ATA transistor and have that coming in the mail this week

    mental note to self, don't assemble kits when you have not slept in over 24 hours lol. the older school luxeon driver from jaycar seems still the best way to go, unless some else has a flexible driver for different led currents, on fleabay i find all kinds of drivers but they are either mains powered or made for a flash light with a fixed current

    Right now i am still trying to find my main uv light power meter and got the second led back up and running on a simpledrive controller but that's a linear driver so it wastes quite a bit of power but both of the led engin 365nm diodes i have been running at 950ma and only need a modest heat sink, all of the Chinese made leds have since failed, one died from my fault and two had the acrylic lens melt and got a refund for them, pictures will be coming soon but by far i believe they are the best on the market for the power level, i want to try to add optics but all that i have are acrylic and i think they would solarize in time and attenuate the power out put.

    I have the simpledrive on the same heat sink with the thermal sensor attached so i don't damage the driver but with only the led on the heat sink they run a lot cooler then the Chinese leds even though there output is almost 10 times the output flux. for events these guys could be hidden a lot easier then a florescent tube, when my finances allow it i will buy the hoya filter glass to kill what little visible light the diodes make.

    I would like to arrange these in series but my experience with the Chinese leds even with balancing resistors make me very wary of doing that, these seem to be close to the intolerance experienced by laser diodes and i have been putting IN4148 or IN914 reverse bias on the leds. the reverse voltage for the uv led is only around 5 volts and the maker just lists that reverse bias is not recommended.
    I have one Nichia NCSU033B P33D22 on the way from Hong Kong on a copper star base for evaluation as well, along with two more of the Chinese leds on the way (i ordered them before i killed the others).
    I don't know of a way to safely series these at the moment and am open to suggestions.

    I know the led engine ones wont compare to a 15 watt or higher fixture for output but they are much easier to hide. The leds i have now are all on the star base and the maker recommends 3 screws to mount them, the led it's self is on a ceramic substrate with a glass optic so the same torque on the screws is important and use plastic washers to avoid shorting out the solder pads, i made my own with a fixture i use for making end plugs for the fireworks i make but the washers are easy to find at most any hardware store.

    On a side note i found a bunch of glow in the dark stars stuck to the ceiling in my bed room i was unaware of, the former owner must have had kids in that room, lol now i want to add more, even though they make some visible light at the led it's self it does not seem to carry that far
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  9. #39
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    sofar so good, i have been running the led engin units at 950ma and so far no problems, i have parts on order to find the driver i damaged and i have 2 more of the cheap ones that i will be testing at there rated power, they do work but as i said are very intolerant of mistakes in drive voltage and i will not be putting them in series, i am going to order a 3rd old school luxeon driver for that, it's odd i cant find anything that offers the features of that obsolete controller
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

  10. #40
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    I found my uv meter! i only had to empty half of the room
    now for some numbers, i did the tests with the sensor about 1cm from the led's lens with a little error as i did not want to make contact with a metal caliper.
    The Led Engin at 680ma i got 95mw/cm^2
    910ma i got 134mw/cm^2
    1 amp gave me about 150mw/cm^2
    The generic fleabay led at 680ma was 63mw/cm^2
    I did not go higher in current as 700ma is the spec and these don't do well above that, now i am going to keep track of operating time, the flux i got on the generic led is brand new, the flux on the Led Engin is after about 10 hours of operation and my second one has about 30 hours and at rated current i get about 155mw/cm^2.
    No optics where used except of course the naked leds
    Remember Remember The 8th of November, When No One Stood, but Kneel, In Surrender
    In a popular government when the laws have ceased to be executed, as this can come only from the corruption of the republic, the state is already lost. Montesquieu

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