ok then ill use those that i have thanks a lot for info
I use 3mm LEDs for my HO locomotives, as the OD of the LED matches the OD of the headlight lens.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
3mm is fine for headlights.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
so the 3mm is good for headlights then ?
Size depends on how much space you have int eh loco. 3mm is about the size of most light bulbs in HO - the ridge aroudn the base of the LED can be filed down if you are careful nut to go too far, for example to get the LED to fit int he channel int he frame of my Proto 2000 Geeps where the original light bulbs were, I file a flat int he base of the LED opposite the existing flat part and the LED drops neatly into place in just the right spot to shine int he light pipe. For locos with no aprticualr palce to actually put the light source, I'll use the 5mm LEDs, mainy just to use them up. If you want to do ditch lights, then you need much smaller LEDs.
FOr the usual white type LEDs used for headlights, use a 1K resistor, Plenty bright and the current is limited to well within the LED's safe range.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
hello all whats size do i need for headlights i have 3mm n 5mm are they any good or do i need smaller ones also how bright can i get them or is it best not to bright ???? im into ho scale an am using dcc ( Lenz ) if that helps out thanks .......