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Using LED calculators like
Why ? Mainly? I just want to experiment with LED lighting. But seconda rily? a 120VAC LED bulb is $25. With some $2 worth of electronics I can make a nice under cabinet light.
I?m not an EE. I don?t know what may be important information, so I? ve included everything I?ve done. I?ve basically started with this art icle
All this? ?I think? I understand.
Now, this is what I?m having difficulty understanding. In the example (a nd everyone else?s) the number of LED?s is quite a bit smaller than cou ld be supported by the voltage available. Thus the current limiting resist or is quite large in both ohms and power rating. In my limited understandi ng, I would think one would want to use more LED?s, thus reducing the amo unt of electricity wasted as heat in the resistor. As a secondary benefit, I?m finding it far easier to find 1/4 and 1/2 watt resistors instead of
2.5W resistors.In my specific example, I used the ?LED Series Resistance Calculator?. The LED?s I have are White LED?s ($3.60 for 100 from China) so I have plenty to try and/or burn up :) They?re rated ~3.5V at 30 mA.
? If I use 25 LED's at 3.5V, 30mA, 161.2V, the calculator says I need a 2
400 ohm, 2.263 Watts current limiting resistor. ? However, if I use 44 LED?s, it suggests I can use a 240 ohm, 0.216 wa tt resistor. Thus, I would be putting out 75% more light for the same amount of electric ity and using an easier to find quarter watt resistor. Is there some other aspect about this circuit that suggests that is a bad idea?Thanks for your help.