I am trying to build a sign with two lamps: one white and one red.
I have been trying to use an LED (the 5mm one seems brighter than the 10mm one). Can someone please recommend how to do this? I would like to have the light be as bright as possible and at least 25mm in size.
I have an led (super bright) and I would like to make it into a "torch". i.e. say its real dimension is 5mm in diameter a person standin say 10meters away, I want him to see it as say a 30mm or even a 40mm diameter light (be it white or red).
How do you want the illumination? From behind the sign or to be reflected from the sign?
You can get reflectors for LEDs... So I have heard... but have never seen one myself. Moreover, LEDs have an angle of viewing... 15deg or 30deg or so...
For your application, wider the better as you can get the intensity by placing the LED closer.
You can use the LED + reflector like a battery powered torch and paste a translucent sign on the glass...
funny enough i seen the insides of those pedestrian crossings attached to lamp posts. All they have to illuminate the "WAIT" sign is what looked like a 60W bulb powered from the mains supply. Not saying you have to adopt the same thing but maybe depending on your application you could use the mains to power some lighting. Most signs ive seen, outdoor ones anyway are wired into the mains.
I think that to illuminate a 40 x 40 mm area uniformly an array (4 x 4 ?) of ordinary 5mm LEDs behind frosted plastic/glass sheet would be better than a single LED. They're cheap enough, and possibly cheaper than a LED + reflector. A simple wall-wart, plus current-limiting resistor(s), could power them.
It probably would have been better to start a new thread, rather than adding onto one that is 5 years old. If you go to the main forum page, select the correct forum, and click the button "create new thread", I'm sure you'll be better off.