Timeline for Increase brightness of parallel LEDs
Current License: CC BY-SA 3.0
13 events
| when toggle format | what | by | license | comment | |
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| Jul 27, 2016 at 21:25 | comment | added | winny | Oh! Warm white and 3.0 V! No wonder it's dim! If they are 5 mm standard though-hole LEDs, aim for 10 mA. I suppose someone has made even weaker chips in even smaller packages but you can go higher than 0.5 mA. Yes! Please do aim for a far more resonable series-parallel setup with say three in series and a resistor for 12 V and 20 mA per group and wire eight of them in parallel. | |
| Jul 27, 2016 at 21:05 | comment | added | Passerby | I have white leds that light to under 0.1mA, 100 microamps uA.. They are dim dots at that point. And with just two AA batteries, unless there is a boost circuit inside I doubt they are in series. | |
| Jul 27, 2016 at 20:53 | comment | added | Andrew Stephens | @winny they aren't quite as dim as I first thought. They are actually warm white LEDs inside round plastic diffusers that have an orange tint. Surely <0.5mA per LED isn't enough to light them? Could the LEDs be wired up in a combination of parallel and serial blocks? I'll have a look another time (two dozen screws to remove to get into the thing!). | |
| Jul 27, 2016 at 20:24 | comment | added | winny | Ah! No wounder it's dim. 20 mA per led is resonable max, but with all wired in parallel, it's impossible to tell other than brightness how well they share. And increase slowly because if one gets too much current, it will get so hot it dims itself, which is very counterproductive. | |
| Jul 27, 2016 at 20:08 | comment | added | Andrew Stephens | @Passerby the batteries aren't brand new, and only a cheap brand. | |
| Jul 27, 2016 at 20:08 | comment | added | Andrew Stephens | @winny the multimeter was in series between batteries and first LED. Probably best if I play around with a variable power supply and resistors as you suggest. Just worried about burning them out though! | |
| Jul 27, 2016 at 20:05 | comment | added | Passerby | That's less than 1 mA each. Could still be lit but arnt bright at all. How fresh are your batteries? Cause it's 11 mA at X voltage. | |
| Jul 27, 2016 at 20:00 | comment | added | winny | 11 mA per LED or total for 25 of them? If they are writes in parallel, you will make the uneven distribution if current a bit worse if you go for a say 5 V supply and drop 2 V over a resistor versus 3 V and no resistor. If you have a variable power supply and a few resistors, you can play around with it. Only problem is if one of them have significantly lower Vf, then that will go very bright for a short while before burning out. | |
| Jul 27, 2016 at 19:49 | comment | added | Andrew Stephens | @winny yes I've just tried it and is reading 11ma. So would you recommend adding a resistor if I was to use a mains adapter? | |
| Jul 27, 2016 at 19:49 | answer | added | Passerby | timeline score: 1 | |
| Jul 27, 2016 at 19:40 | review | First posts | |||
| Jul 27, 2016 at 19:58 | |||||
| Jul 27, 2016 at 19:40 | comment | added | winny | Crappy product assuming high resistance of the battery. The LEDs will not last long if you use good batteries. Do you have any means to measure the current drawn from the battery, like a multimeter? | |
| Jul 27, 2016 at 19:37 | history | asked | Andrew Stephens | CC BY-SA 3.0 |