Electronics > Beginners
Car battery confusion.
mariush:
Yeah, but at this point wouldn't it be cheaper to just ORDER a bunch of led drivers from an online store and get them by next week?
Are you in that much of a rush to complete this project?
Seems like a waste to use one LM317 per 2 leds... not to mention they're not that accurate at low currents...
If you don't want to deal with microcontrollers, there's more basic led drivers/ current regulators like these for example: https://uk.farnell.com/w/c/led-lighting-components/led-driver-ics/led-drivers?no-of-outputs=1outputs&no-of-pins=2pins
NSI45020AT1G : https://uk.farnell.com/on-semiconductor/nsi45020at1g/ic-led-driver-45v-0-02a-sod123/dp/1794973
You put it in series with your leds and it limits the chain to 20mA +/- 20% ... simple as that.
Others available for various current amounts like 10mA (NSI50010YT1G) , 30mA (nsi45030at1g), 100mA (nsi45060jdt4g), and some have a 3rd pin you can use to limit current lower than preset value using a resistor.... NSI50150ADT4G for example with maximum 350mA current.
Siwastaja:
Yes, these two pin series constant current regulators are the greatest thing since sliced bread. They are like the series resistors, but actually regulate the current. If it all possible, just order some. One per LED chain.
"Voltage overhead" of 1.8V is fairly good if you compare it to a LM317-based constant-current regulator (2 + 1.2 = 3.2V), so you are probably able to put three LEDs per chain, and reduce power dissipation compared to a simple resistor which needs to drop more in order to regulate acceptably.
Navigation
[0] Message Index
[*] Previous page
Go to full version