Forum: General Electronics Technical Discussion
11-24-2015, 09:19 PM
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Replies: 146
Views: 11,856
Re: Need help reading a schematic.
Edge-lit (one LED) blue/white 64-80 ohms; yellow-green 44-56 ohms to give 20-25mA. You have a bit of range there.
The back-lit displays use more LED's so the original 16 ohm R2 was for a 5 LED array.
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Forum: General Electronics Technical Discussion
11-24-2015, 08:04 PM
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Replies: 146
Views: 11,856
Re: Need help reading a schematic.
The Ohm's Law formula you use depends on what numbers you know. (I might have forgotten the E squared in my post, sorry if that confused).
Two ways to do it, look at voltage across the resistor or...
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Forum: General Electronics Technical Discussion
11-24-2015, 05:24 PM
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Replies: 146
Views: 11,856
Re: Need help reading a schematic.
You can calculate a resistor's power dissipation two ways- knowing voltage across it, or knowing current flow.
For resistor R2, it does not have 5V across it because the LCD backlight uses some....
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Forum: General Electronics Technical Discussion
11-15-2015, 10:44 PM
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Replies: 146
Views: 11,856
Re: Need help reading a schematic.
It's a bit of a Euro schematic - and some people like to run wires all over and some like to use Nets.
I think you are getting mixed up with component pin names and net labels. Also Belgium has...
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