LED Basics for Model Railroaders
LEDs are perfect for model railroads - they're small, bright, efficient, and last forever.
LED Types
Through-Hole LEDs
- 3mm: Good for N/HO signals
- 5mm: Buildings, larger signals
- Easy to solder
Surface Mount (SMD)
- 0402, 0603, 0805: Tiny, for N scale
- 1206, 3528: HO scale buildings
- Require fine soldering skills
LED Strips
- 12V DC strips: Easy building lighting
- Warm white (3000K): Incandescent look
- Cut at marked points only
The Golden Rule: Current Limiting
LEDs MUST have current limiting resistors!
Formula
R = (Vsupply - Vled) / I
Quick Reference (12V supply, 10mA)
- Red/Yellow/Green: 1KΩ
- Blue/White: 820Ω-1KΩ
- **Safe universal: 1KΩ works for all**
Color Selection
Buildings
- Warm white (2700-3000K): Residential
- Cool white (5000K+): Fluorescent/industrial
- Yellow: Incandescent simulation
Signals
- Use designated signal colors
- Red: Stop/danger
- Yellow: Approach/caution
- Green: Clear/proceed
Installation Tips
- **Polarity:** LEDs have + and - sides
- **Heat:** Use heatsink when soldering
- **Diffusion:** Sand or paint for softer light
- **Hiding:** Use black tubing to direct light
- **Testing:** Always test before final install