sanding leds

c_mon · Post by **c_mon** » Sun Mar 11, 2007 10:02 am

Why should the leds be sanded and how is it done? Fine grade?

Kurt_ · Post by **Kurt_** » Sun Mar 11, 2007 1:11 pm

The LED's don't have to be sanded, but it produces a more diffused light, so the screen doesn't have lihgt/dark spots on it. You should use a fine grade sandpaper, but not extremely fine. Basically, you just wanna rough up the surface a bit until it isn't clear.

c_mon · Post by **c_mon** » Sun Mar 11, 2007 3:35 pm

Kurt_ wrote:The LED's don't have to be sanded, but it produces a more diffused light, so the screen doesn't have lihgt/dark spots on it. You should use a fine grade sandpaper, but not extremely fine. Basically, you just wanna rough up the surface a bit until it isn't clear.

Thanks. Does 'light/dark spots' mean 'areas' or just spots as wide as a pixel?

Bibin · Post by **Bibin** » Sun Mar 11, 2007 3:47 pm

He means areas of the screen that are more well lit that others, versus poorly lit portions.

Kurt_ · Post by **Kurt_** » Sun Mar 11, 2007 6:14 pm

A really good example of this is a really good portable, mminus this problem. A dreamcast portable, one of the only ones.

As you can see, this one uses 3 LED's.

c_mon · Post by **c_mon** » Sun Mar 11, 2007 6:41 pm

Kurt_ wrote:A really good example of this is a really good portable, mminus this problem. A dreamcast portable, one of the only ones.

As you can see, this one uses 3 LED's.

How about this? 6 leds and 2 10ohm resistors

Sanding all leds will work quite well, I think.

Kurt_ · Post by **Kurt_** » Sun Mar 11, 2007 6:58 pm

For 6 LED's you'll need roughly 27 ohms. Also, the LED layout should be three on the top and three on the bottom.

One in each corner, one in the middle top, and one in the middle bottom.

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Here's a picture of my setup. 6 LED's, as above, with a 27 ohm 1/4 Watt (I didn't have a 1/8W handy but it'll work and is smaller) resistor.

http://spinit.org/images/7773SNES%20003.jpg

c_mon · Post by **c_mon** » Sun Mar 11, 2007 7:02 pm

Kurt_ wrote:For 6 LED's you'll need roughly 27 ohms. Also, the LED layout should be three on the top and three on the bottom.

One in each corner, one in the middle top, and one in the middle bottom.
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You know, there is the ribbon cable of the screen at the bottom so it's nearly impossible to put a led in the middle of the bottom

Kurt_ · Post by **Kurt_** » Sun Mar 11, 2007 7:03 pm

You do know you open the screen right? And look at the post edit above

c_mon · Post by **c_mon** » Sun Mar 11, 2007 7:07 pm

You know, there is the ribbon cable of the screen at the bottom so it's nearly impossible to put a led in the middle of the bottom and also I should say that the resistors are powered via separate power cables taken from the 7805 IC. So why not 2 X 10ohmsfor3leds?

Kurt_ · Post by **Kurt_** » Mon Mar 12, 2007 10:52 am

http://led.linear1.org/led.wiz

Because it doesn't work that way. Use that to calculate an appropriate resistor. Any less than appropriate and your LED's life will be decreased.

http://common.ziffdavisinternet.com/uti ... 093,00.jpg

This is the PSOne screen opened. There is room at the bottom.

c_mon · Post by **c_mon** » Mon Mar 12, 2007 11:05 am

Kurt_ wrote:http://led.linear1.org/led.wiz

Because it doesn't work that way. Use that to calculate an appropriate resistor. Any less than appropriate and your LED's life will be decreased.

http://common.ziffdavisinternet.com/uti ... 093,00.jpg

This is the PSOne screen opened. There is room at the bottom.

Of course there is room for the led, but where do you think you can wire it? And also I'm still not sure if it's not going to work with my solution. Isn't it 10ohm for three leds? If yes, I'm just going to apply the rule twice. That's all I want to do. I'm using two seperate 10ohms. What's wrong with it?

Kurt_ · Post by **Kurt_** » Mon Mar 12, 2007 12:42 pm

It's 7 ohms too little. It doesn't work like that. Doubling the resistor for double the LED's is like saying cooking a roast for 6 hours at 750 F is the same as cooking a roast for 3 hours at 375 F. But the roast will burn and turn charred, because 750 F is just too damn hot.

As for hooking them up, you connect all the positive leads together and then all the negative leads together, and hook a positive to the regulator and a negative to ground. You should invest in some 28 gauge wire. It's thin and will easily fit inside the screen's channels.

timmeh87 · Post by **timmeh87** » Thu Mar 22, 2007 4:37 pm

actually doubling the resistor for double the LEDs is more like saying you cook a roast for 6 hours at 350, so you can cook it for 3 hours at 150.

it dosen't even make sense

Edutainment · Post by **Edutainment** » Fri Mar 23, 2007 2:02 pm

Kurt_ wrote:It's 7 ohms too little. It doesn't work like that. Doubling the resistor for double the LED's is like saying cooking a roast for 6 hours at 750 F is the same as cooking a roast for 3 hours at 375 F. But the roast will burn and turn charred, because 750 F is just too damn hot.

Don't you mean "it's like saying cooking a roast doe 6 hours at 375 is the same as 3 hours at 750."

I could be wrong...

Would I have to LED mod a Hip Gear or does this only apply to the PSOne screen?