I used to build 1W LED lights with current regulators, but recently happened to try some ½W white 5mm leds. I have a couple of them and want to install them at different locations. However it wouldnt be economical if I use a linear current regulator like LM317 as it would cost me 2 times what the LED itself costs. I have a +5V DC source everywhere, so that would be the supply. So my question is, is it okay to drive a ½W LED with a resistor? I tried a bench test with a 12ohm ½W resistor on +5V. It lights bright, runs on 4.6V and 68mA current. Is this normal? AFAIK, white ½W leds run at 3.7-4.5V and at 120-150mA. The 68mA current is fine, but what about voltage? The overall LED power seems at 0.313W for this 0.5W LED which is also ok. I would only be using this for small durations and not a permenantly on setup. ANy help here please?
Edit: Running on a linear current regulator of LM317 and a 12ohm resistor and 12v source, I get 4.3V@ 106mA on the led which is perfect, but cant it even be close with a resistor?
Edit: Running on a linear current regulator of LM317 and a 12ohm resistor and 12v source, I get 4.3V@ 106mA on the led which is perfect, but cant it even be close with a resistor?
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