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LED Bed Design Improvments (Part 2)

Posted Oct 13 2005 - 2:40pm by robogeek
Filed under Block Diagram | electronics | LED | PCB | Schematics

Well its been a couple days and I have completed the current design of the LED bed Adaptive color controller.

Therory of operation:
1. A set of 3 photo-diodes each tuned to red, green, and blue light will convert light into voltage.
2. A 2-stage Amplifier circuit for each color(red, Green, Blue, and White) will provide the control to a FET
a) the first stage is an inverting amp with a -1 gain.
b) the second stage is set up as a voltage controlled Current Source, using the Amp and the FET
3. The current source will change current based on the output voltage from the Photo-Diodes.

Schematic:
LED BED - Schematics

There is a set of 3 boards to accomplish this task, due to the fact that they might not be located in the same location.

You can note the large circle around the LEDs and the Photo diodes in the layouts, this is for a custom made metal sheild that will enclose the Photodiodes and shield them from the white Illuminators because we don't want them to be saturated by the white leds do we. In the case of the LED board the shield will be able to hold a lens to help diffuse the light around the room.

Layouts:
LED Bed PCB Layouts

One has to choose the current setting resistors with care there is a chart in this file that shows what value you should used based on the number of LED boards, as well as, what size power source you should use.

here is an interconnect diagram:
LED BED - Block Diagram

attached are PDFs of the block diagram, PCB Layout and Schematics, as well as the Excell chart

If you need the gerbers or have any other questions just leave a comment and i'll get back to you.

Robogeek

Trackback URL for this post:

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AttachmentSize
LED BED - BLOCK DIAGRAM.pdf13.25 KB
LED BED - SCHEMATIC.pdf30.29 KB
LED BED - PCB LAYOUTS.pdf165.19 KB
LED BED - Info.xls24 KB
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Parts list

Can you post a parts list or BOM? Would be great to have some step-by-step instructions for those of us that aren't as technically inclined.

This is really cool and something I'd like to do.

Thanks

By gsulcer at October 16, 2005 - 7:47am | login or register to post comments | email this page

Excellent work. could you

Excellent work. could you please post the gerber files, along with a parts list. i really have no idea where to start on this one.

Also i am looking for people to split the Qty 500 x $1.11 = $555 of these pcb http://www.blogcadre.com/blog/robogeek/led_bed_design_improvments_2005_10_06_14_17_56

i really only need like 100 of them.

By darkhalo (not verified) at October 18, 2005 - 12:12pm | login or register to post comments | email this page

TRI-LED's

I was also wondering about the tri LED's. Do you think that they will have less intensity than three serperate leds? Thanks again,

eric

By darkhalo (not verified) at October 18, 2005 - 12:31pm | login or register to post comments | email this page

Update on design

I have looked at the Tri-color LED and designed a new board for it, it is less than 25% the size of the current LED board and will be just as bright. it will also use less separate LEDs therefore cost less in components as well.

I have priced out every component new from digikey and put together a parts list. I also have Panelized a single circuit board to the specifications at http://www.goldphoenixpcb.biz/special_price.php and was able to get 6 sets of boards. A set is listet below:

  • 1 driver
  • 1 Color Sensor
  • 25 Tri-color LED boards

One panel is able to fit 6 Sets of boards and therefore costs $20 Per set. I priced out all the componenets necessary new From Digikey, Future Electronics, and Best Hong Kong. and to complete these kits with all the parts necessary including boards, Cables, and power supplies is $150 + shipping to me/6 + shipping to you, no profit.

I will be willing to order all of it if I can get 5-6 people to commit to buying Kits, or if you just want the boards remember they are $120 for the 6 sets. which for Darkhalo might be a better deal.

I will be posting the price list/bom later.

Robogeek

By robogeek at October 20, 2005 - 11:14am | login or register to post comments | email this page

Tri-LEDs

The Tri-LEDs that I have found have a brightness of 2000 mcd/per color which are not as bright as some but I figure if you have enough of them they would make up the difference. if not, we can always go with surface mount LED's to reduce the size of the boards.

Robogeek

PS.. google ads are cool: http://www.hebeiltd.com.cn has tricolor LEDs with 2000mcd for red and blue and 5000mcd for green.

By robogeek at October 23, 2005 - 11:25pm | login or register to post comments | email this page

Parts list

The ZXM3A13F doesn't seem to exist, or am I missing something? There is a ZXMP3A13F... So which one is the correct one, and which alternative FET's will do the job also?
Thanks!!

By Jason Matthews (not verified) at March 18, 2006 - 8:37pm | login or register to post comments | email this page