ultra Posted February 24, 2007 Report Share Posted February 24, 2007 hello,i'm in search of a very small green led that accepts the standard voltages of the dout module. it's difficult for me to measure exactly what i need, but it's about half the height of a T1 led, and the same (slightly smaller would be better) diameter without the edge piece at the bottom. this is to fit inside the e-switch TL1240 tact switch. any help? thanks.drew Quote Link to comment Share on other sites More sharing options...
pay_c Posted February 25, 2007 Report Share Posted February 25, 2007 The only thing I know are 1,8 mm LEDs. Try a google search on that, should be somewhere (I only know them in a bright nice red version @ Reichelt).There are also 1,5 mm LEDs, but as they are build in a rectangle form and the light´s coming out at the side of the rectangle (and there is the 1,5 mm round piece) this is not as small as it could be.Whats about SMD LED´s? They come in various forms and the soldering is not to hard with some practice.As long as you don´t buy extra (ultra) bright LEDs everything will be compatible with the DOUT.Greetz! Quote Link to comment Share on other sites More sharing options...
Wilba Posted February 25, 2007 Report Share Posted February 25, 2007 You can use extra (ultra) bright LEDs, you just need to increase the resistor from 200 ohms to 1K. But you probably won't find them smaller than 3mm. Quote Link to comment Share on other sites More sharing options...
Sasha Posted February 25, 2007 Report Share Posted February 25, 2007 I would also used SMD LEDs at your place. I bought one for testing button illumination, and it is great. Mine is ultra bright with very wide illumination angle. Pretty expensive if you need much. I bought mine for about 0.60-0.70 EUR. Also, it is not so dificult to solder wires once you fix it using clip or something... Quote Link to comment Share on other sites More sharing options...
pay_c Posted February 25, 2007 Report Share Posted February 25, 2007 You can use extra (ultra) bright LEDs, you just need to increase the resistor from 200 ohms to 1K. But you probably won't find them smaller than 3mm.Eeeeeeeeeerrrr, are you sure, Wilba? Super / Ultra bright LEDs normally need more current & voltage (like 1,5 Volts and 30 mA) and so you should go *down* with the resistance to something like 150 Ohm (but not much more as the 74HCxxx´s are not capable of bringing up to much current) so you got a nice bright LED. Quote Link to comment Share on other sites More sharing options...
Wilba Posted February 25, 2007 Report Share Posted February 25, 2007 Eeeeeeeeeerrrr, are you sure, Wilba? Super / Ultra bright LEDs normally need more current & voltage (like 1,5 Volts and 30 mA) and so you should go *down* with the resistance to something like 150 Ohm (but not much more as the 74HCxxx´s are not capable of bringing up to much current) so you got a nice bright LED.Most of the Super/Ultra bright LEDs will give maximum light output at 25mA or higher, but you can get a "normal" LED light output by dropping the current. They'll quite happily work at 1.5mA... i.e. take an ultra bright blue LED with a 3.5v forward voltage drop, with 5v supply, that's 1.5v across the resistor, divide by 1000 ohms, gives 1.5mA. They're still just visible when using a 10K resistor (that's 0.15mA!)This works because the Super/Ultra bright LEDs are in the 1000s of mcd and "normal" LEDs are maybe 150 mcd max.The 74HC595 has a max current output too (per pin), so even if you wanted to drive LEDs at 25mA, you probably couldn't.The other good thing about Super/Ultra bright LEDs... when you start multiplexing them (i.e. LED matrix) then the extra brightness offsets the fact they're only on for 1/8th the time. ;D Quote Link to comment Share on other sites More sharing options...
ultra Posted February 26, 2007 Author Report Share Posted February 26, 2007 thanks guys, i found some smd leds for 16 cents each and they should fit into my switch just fine :). Quote Link to comment Share on other sites More sharing options...
pay_c Posted February 26, 2007 Report Share Posted February 26, 2007 The other good thing about Super/Ultra bright LEDs... when you start multiplexing them (i.e. LED matrix) then the extra brightness offsets the fact they're only on for 1/8th the time. ;DThaaaat´s some good point, had the problem like some times but never thought of that. Will try that next time. :-* Quote Link to comment Share on other sites More sharing options...
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