input on led

[skullkeeper]

i was browsing around ebay and found thes two bulbs think eather would work maybe please comint on it

http://cgi.ebay.com/AC-110V-18-LEDs...768789596QQcategoryZ16037QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/LED-R30-Spot-Fl...667322018QQcategoryZ88433QQrdZ1QQcmdZViewItem

 

[Just In KY 2002]

The first link definately no. 10,000mcd is nothing. I have a single LED capable of 120,000mcd, and I'm going to use nearly 200 of those to make a clear screen. I currently have 100 of those, and can see the screen, but any room lighting totally kills the picture.

The second link is better, but still nowhere near what you need. Just think of a 40 watt lightbulb. (360* output compared to LED 180* and less heat loss.) There's no way a 40 watt bulb would be bright enough for a DIY projector.

Here's the LEDs that I am using 180-200 of:
http://www.lck-led.com/product_info.php?products_id=162
Also can be found on ebay.

 

[skullkeeper]

ok how about these http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7582798668&fromMakeTrack=true

 

[skullkeeper]

what type of pc board should i get and how maney holes will it need to have for 200 leds? 400 or more? do i need holes for eack resister also? sorry new at this dont know a hole lot about conecting led's yet.

 

[Just In KY 2002]

The last link that you gave me looks about right.

I'll try to give you a lot of information on the LEDs, but you might get confused as well.

The LEDs that I am using are 10mm, but have 4l ight emmiting sources in each LED. Think of a light bulb with 4 filaments in it. 4 at 30,000mcd = my 120,000mcd. Mine are rated between 60-80 milliamps.

These that you posted are 10mm, 130,000mcd, and appear to have only one source per LED, and run at 20-30 milliamps.

The milliamps per LED and the way you wire them will determine how many resistors you will need. Yours come with a 510ohm resistor for each LED so you would need to wire each led in parallel to a resistor:

+ is positive wire
? is resistor
@ is LED
| is negative side of LED
- is negative wire (ground)
. is nothing

+++++++++++++++++++++
....?.......?.......?.......?.......?......
....@......@......@.....@......@.....
.....|.......|.........|.......|.......|......
--------------------------------------

This setup will not work with your wall socket voltage (110AC). You will have to find a suitable power supply that is 12-13.5volts and about 10 amps.




The circuit board needs to be the size of your screen minus a few centimeters. You want to end up with a pattern where there is an LED every 3 or less centimeters:

X..X..X..X..X..X..X..X..X..X..X
..X..X..X..X..X..X..X..X..X..X..
X..X..X..X..X..X..X..X..X..X..X
..X..X..X..X..X..X..X..X..X..X..
X..X..X..X..X..X..X..X..X..X..X
..X..X..X..X..X..X..X..X..X..X..
X..X..X..X..X..X..X..X..X..X..X

They will all have to be aimed squarely at the monitor from 12-18 inches depending on your lenses. I used 11 by 9 originally, and am waiting for more LEDs to come so I can add in the rows that starts off like ..X

Use:
LED Board---->LCD Screen----->Fresnel------->Exit lense
There is no need for the other fresnel.

 

[Just In KY 2002]

Watch the shipping price on those too...
$39.99 + $30 s/h

 

[zaner21]

+ is positive wire
? is resistor
@ is LED
| is negative side of LED
- is negative wire (ground)
. is nothing

+++++++++++++++++++++
....?.......?.......?.......?.......?......
....@......@......@.....@......@.....
.....|.......|.........|.......|.......|......
--------------------------------------

[/B]

Do you have to have a resistor with each LED or could you put a bigger resistor at the beginning of each row of led’s?

Zaner21

+...?...@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | -
+...?...@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | -
+...?...@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | -
+...?...@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | +@ | -

 

[skullkeeper]

cool that helped alot do you have any pic of how it should look that would help even more

 

[Just In KY 2002]

The most LEDs you would want to put in series is 3 of the 3 volt LEDs, or 4 of the 2 volt LEDs, and you would need a smaller resistor. I'm using 2 LEDs with a 200 ohm resistor. >Here is a link to a resistor calculator<

I don't have any pics yet, but will when I get it finished.

For the LED haters... I have a clear usable picture that is about 110" in the dark.