Categories
Latest News
- 200W+50W Bi-Amp Power Section and Crossover Replacement For Advent Powered Speakers.
- Darker Downtime…
- Curiously Strong Power Supply Design
- ATTiny44 Based Shifty VU Meter Controller (MAKE2008)
- Curiously Strong TriAmp Speaker Selection
- Grow LED Array Rev.2 Results AKA Why Rev.3
- Grow LED Array Prototype Rev. 2
- MAKE 2008 Grow LEDs Array Prototype Design
- Stereo Audio IO Landing Pad for Olimex SAM7-H256: Assembled
- Jabra BT125 Bluetooth Headset Teardown
Monthly archives
- October 2008
- September 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- October 2007
- September 2007
Search
MAKE 2008 Grow LEDs Array Prototype Design
Single sided board design for an array of 24 blue, 24 red, and 2 white LED. For use as small plant lighting. Switching (SMPS) power supply and optional digital control unit are external, and support a minimum of 2 arrays. The white LED are switched with a latching button. Series strings of LED are brightness regulated using MMBT3906 based current sources for immunity to poorly matched Vf and variable supply voltages, 8 blue LED and 6 red LED per string. This setup will be powered by 24V rails, to provide headroom for the LED strings at Vf(max) and and 1V needed by the current regulators. A control unit will modulate power with PWM switching at greater than 200Hz, and be capable of simulating day/night cycles, movement of the sun from horizon to horizon, and adjusting the red and blue light balance.
Posted by rmrubin 
March 2008