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I'm sorry I can't help you, but after reading an article posted here about melatonin I got interested in light therapy, but commercial devices are a bit expensi

I'm sorry I can't help you, but after reading an article posted here about melatonin I got interested in light therapy, but commercial devices are a bit expensive. Are you documenting your project?

mafuyu 8y ago
Sure, it's not the most exciting project, but I might do a short writeup when I'm done. I originally purchased these nice LED strip bars with enclosure in blue[0], but after reading this site by the manufacturers of a commercial green therapy light[1], I was convinced to switch to turquoise/cyan. Turquoise isn't that popular so I wasn't able to find any strips/bars, and I got these individual 3W bead LED modules instead.[2] For the Hue integration, I'm using a Mesh Bee + UartSBee v5[3] with firmware from PeeVeeOne[4]. It outputs PWM, and I'm hooking it up to a cheapo constant current LED driver I got from Aliexpress. Since all the LEDs need to be in series for a constant current driver, I'm probably looking at a ~20V power supply to power the whole thing. My bedframe has a headboard, so I'm planning on 3D printing some mounts that clamp on top. [0]: https://www.ebay.com/itm/50CM-U-Aluminium-shell-DC-12V-36-SMD-5630-LED-Hard-Rigid-LED-Strip-Bar/332644356624 https://www.ebay.com/itm/50CM-U-Aluminium-shell-DC-12V-36-SM... [1]: http://www.sunnexbiotech.com/blue%20vs%20green%20light.html http://www.sunnexbiotech.com/blue%20vs%20green%20light.html [2]: https://www.aliexpress.com/item/10-pcs-3W-Turquoise-Cyan-LEDs-Diode-Beads-Lamp-Chip-Emitter-700ma-3Watt-Chip-type-500nm/32812975950.html https://www.aliexpress.com/item/10-pcs-3W-Turquoise-Cyan-LED... [3a]: https://www.seeedstudio.com/Mesh-Bee-Open-Source-Zigbee-Pro-Module-with-MCU-(JN5168)-p-1751.html https://www.seeedstudio.com/Mesh-Bee-Open-Source-Zigbee-Pro-... [3b]: https://www.seeedstudio.com/UartSBee-V5-p-1752.html https://www.seeedstudio.com/UartSBee-V5-p-1752.html [4]: https://peeveeone.com/?page_id=252 https://peeveeone.com/?page_id=252
- fpgaminer 8y ago
  You're a hero; thank you for posting details.
- justinc8687 8y ago
  I would be very interested to see a write up of what you are doing here as I have a similar problem. Any chance you could share one if you create one? Email in my profile.
  - mafuyu 8y ago
    Yep, will do!
- bb88 8y ago
  So those cyan LED's have a forward voltage drop of 3.2-3.6 volts. So you'd be looking at a 32V-36V 350ma power supply or thereabouts to hook them up in series. If it were me, I'd probably run everything in parallel just to keep the voltages lower, and be able to use readily available power adapters. Aliexpress has a PWM controlled constant current driver that takes 5-35V in and outputs 350ma max [1]. 10 of them are $20, so they're not too expensive. At a forward voltage of 3.3V for the LED's, you'd be looking at slightly more than 1W per LED at 350ma (P = VI). Those constant current supplies probably have an efficiency of maybe 66%, taking that into consideration, I would think a 12V 2A power supply would be enough to drive the entire thing. And that could be a wall wart that you get at the local hardware store. [1] https://www.aliexpress.com/store/product/10PCS-A58B-1W-LED-Driver-350mA-PWM-dimming-input-5-35V-DC-DC-step-down-constant/512100_32341525484.html?ws_ab_test=searchweb0_0,searchweb201602_3_10152_10151_10065_10344_10130_10068_10324_10547_10342_10325_10546_10343_10340_10548_10341_315_10545_10696_10084_531_10083_10618_10307_10059_100031_10103_10624_10623_10622_10621_10620,searchweb201603_16,ppcSwitch_4&algo_expid=0bf1386d-f632-4338-852b-0d438aba912a-10&algo_pvid=0bf1386d-f632-4338-852b-0d438aba912a&priceBeautifyAB=0 https://www.aliexpress.com/store/product/10PCS-A58B-1W-LED-D...
  - mafuyu 8y ago
    Just tested with my power supply, and the minimum V_on seems to be about 2.7V. So if I want to drive all 10 in series, I'll need 30V+. If I had three banks in a 4,3,3 configuration, I could get away with a 12V power supply as well, which would be nice since I already have a bunch of 12V 5A wall warts. I already got the board you linked, supposedly configured for 700 mA. Haven't tested yet. The datasheet for the part says it can go up to 2A[0], so I could potentially modify the feedback circuit for 1A, which would reach the full 3W rating of the LEDs. One issue with that driver chip is that the PWM/enable is active low, so I think I may just stick an inverter on the output of the Mesh Bee. The SDK for the NXP part has changed since the ZLL repo was updated, and I haven't had much luck getting it to compile myself. [0]: http://www.xlsemi.com/datasheet/XL4001%20datasheet.pdf http://www.xlsemi.com/datasheet/XL4001%20datasheet.pdf
    - bb88 8y ago

I'm sorry I can't help you, but after reading an article posted here about melatonin I got interested in light therapy, but commercial devices are a bit expensive. Are you documenting your project?

mafuyu 8y ago

Sure, it's not the most exciting project, but I might do a short writeup when I'm done. I originally purchased these nice LED strip bars with enclosure in blue[0], but after reading this site by the manufacturers of a commercial green therapy light[1], I was convinced to switch to turquoise/cyan. Turquoise isn't that popular so I wasn't able to find any strips/bars, and I got these individual 3W bead LED modules instead.[2] For the Hue integration, I'm using a Mesh Bee + UartSBee v5[3] with firmware from PeeVeeOne[4]. It outputs PWM, and I'm hooking it up to a cheapo constant current LED driver I got from Aliexpress. Since all the LEDs need to be in series for a constant current driver, I'm probably looking at a ~20V power supply to power the whole thing. My bedframe has a headboard, so I'm planning on 3D printing some mounts that clamp on top. [0]: https://www.ebay.com/itm/50CM-U-Aluminium-shell-DC-12V-36-SMD-5630-LED-Hard-Rigid-LED-Strip-Bar/332644356624 https://www.ebay.com/itm/50CM-U-Aluminium-shell-DC-12V-36-SM... [1]: http://www.sunnexbiotech.com/blue%20vs%20green%20light.html http://www.sunnexbiotech.com/blue%20vs%20green%20light.html [2]: https://www.aliexpress.com/item/10-pcs-3W-Turquoise-Cyan-LEDs-Diode-Beads-Lamp-Chip-Emitter-700ma-3Watt-Chip-type-500nm/32812975950.html https://www.aliexpress.com/item/10-pcs-3W-Turquoise-Cyan-LED... [3a]: https://www.seeedstudio.com/Mesh-Bee-Open-Source-Zigbee-Pro-Module-with-MCU-(JN5168)-p-1751.html https://www.seeedstudio.com/Mesh-Bee-Open-Source-Zigbee-Pro-... [3b]: https://www.seeedstudio.com/UartSBee-V5-p-1752.html https://www.seeedstudio.com/UartSBee-V5-p-1752.html [4]: https://peeveeone.com/?page_id=252 https://peeveeone.com/?page_id=252

fpgaminer 8y ago
You're a hero; thank you for posting details.
justinc8687 8y ago
I would be very interested to see a write up of what you are doing here as I have a similar problem. Any chance you could share one if you create one? Email in my profile.
- mafuyu 8y ago
  Yep, will do!
bb88 8y ago
So those cyan LED's have a forward voltage drop of 3.2-3.6 volts. So you'd be looking at a 32V-36V 350ma power supply or thereabouts to hook them up in series. If it were me, I'd probably run everything in parallel just to keep the voltages lower, and be able to use readily available power adapters. Aliexpress has a PWM controlled constant current driver that takes 5-35V in and outputs 350ma max [1]. 10 of them are $20, so they're not too expensive. At a forward voltage of 3.3V for the LED's, you'd be looking at slightly more than 1W per LED at 350ma (P = VI). Those constant current supplies probably have an efficiency of maybe 66%, taking that into consideration, I would think a 12V 2A power supply would be enough to drive the entire thing. And that could be a wall wart that you get at the local hardware store. [1] https://www.aliexpress.com/store/product/10PCS-A58B-1W-LED-Driver-350mA-PWM-dimming-input-5-35V-DC-DC-step-down-constant/512100_32341525484.html?ws_ab_test=searchweb0_0,searchweb201602_3_10152_10151_10065_10344_10130_10068_10324_10547_10342_10325_10546_10343_10340_10548_10341_315_10545_10696_10084_531_10083_10618_10307_10059_100031_10103_10624_10623_10622_10621_10620,searchweb201603_16,ppcSwitch_4&algo_expid=0bf1386d-f632-4338-852b-0d438aba912a-10&algo_pvid=0bf1386d-f632-4338-852b-0d438aba912a&priceBeautifyAB=0 https://www.aliexpress.com/store/product/10PCS-A58B-1W-LED-D...
- mafuyu 8y ago
  Just tested with my power supply, and the minimum V_on seems to be about 2.7V. So if I want to drive all 10 in series, I'll need 30V+. If I had three banks in a 4,3,3 configuration, I could get away with a 12V power supply as well, which would be nice since I already have a bunch of 12V 5A wall warts. I already got the board you linked, supposedly configured for 700 mA. Haven't tested yet. The datasheet for the part says it can go up to 2A[0], so I could potentially modify the feedback circuit for 1A, which would reach the full 3W rating of the LEDs. One issue with that driver chip is that the PWM/enable is active low, so I think I may just stick an inverter on the output of the Mesh Bee. The SDK for the NXP part has changed since the ZLL repo was updated, and I haven't had much luck getting it to compile myself. [0]: http://www.xlsemi.com/datasheet/XL4001%20datasheet.pdf http://www.xlsemi.com/datasheet/XL4001%20datasheet.pdf
  - bb88 8y ago