[?]how do you install led s in a locomotive withought frying the led?[?]
in an N scale locomotive might I add
You have to wire a 1K Ohm resistor into one of the LED leads. It doesn’t matter which one, but the resistor will prevent the LED from burning out.
Alternatively, if there’s room inside the locomotive, you can add a constant lighting circuit as described on page 62 of the August 2006 issue of Model Railroader and substitute LEDs for the grain-of-rice bulbs. A resistor will still be needed for the LED, but the value will be less than 1K because the diodes drop some of the voltage. The two diodes in series with the LED are going to drop a total of 1.2V x 3, or 3.6V. Assuming a track voltage of 12V DC, you need to drop 8.4V through the resistor. Assuming an LED with a current draw of 15mA, Ohms law tells us that the resistor value needs to be R=E/I (Resistance = Voltage divided by Amperage), or 8.4 divided by .015, which equals 560 Ohms.
Page 33 of the August 2006 issue of Model Railroader has detailed information about wiring LEDs to a DCC decoder.
thanks! I’ll try it!