Timeline for Understanding this LM317 LED Driver circuit
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 26, 2015 at 13:58 | answer | added | EM Fields | timeline score: 1 | |
| Jul 26, 2015 at 12:01 | comment | added | Spehro 'speff' Pefhany | Sure, and you said so explicitly up front. I just wanted to add a comment so others in the future would realize what exactly you meant by "power losses". | |
| Jul 26, 2015 at 7:45 | comment | added | Dallas Carter | Thanks Spehro , I am aware of it not being an efficient circuit. I just posted this to understand the circuit | |
| Jul 25, 2015 at 22:29 | comment | added | Spehro 'speff' Pefhany | It should be noted that this circuit is horrible for battery use as it has 'headroom' of 1.25V for the sense resistor, plus the dropout voltage of the LM317. That's a total of 4.25V recommended, more like 3.25V typically at moderate current. So if your LED requires 3V then your regulation will start to fail at around 6.25V so the efficiency is guaranteed to be less than 50%. | |
| Jul 25, 2015 at 22:07 | vote | accept | Dallas Carter | ||
| Jul 25, 2015 at 21:52 | answer | added | Ignacio Vazquez-Abrams | timeline score: 3 | |
| Jul 25, 2015 at 21:49 | history | asked | Dallas Carter | CC BY-SA 3.0 |