resistors for 1.5v bulbs : LUSENET : Wiring for DCC : One Thread

I know there must be a formula to work out the optimum resistance to use to give good brilliance on 1.5v bulbs without frying them. I hear of values like 500R to 1K, with 680R being common, but I imagine it is also influenced by the wattage of the bulbs. I have bulbs that range in wattage from (mA) 12 (nominal 15?) to 47 (50?) and up to 80.

I have also read of the need to use current limiting resistors if 12-16v bulbs are rated at more than 50 mA. Is using 1.5v bulbs that are drawing 80 mA an issue?


-- Nelson Kennedy (, October 07, 2001


See this link for a good explanation and help.

Dale Gloer

-- Dale Gloer (, October 08, 2001.

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