I bought 2 white led's from my local hobby store,and installed them.They looked great for a few seconds then seemed to burn out.I had them installed in 2 Atlas SD 60's,in the holes where the old led went.Was i supposed to get a diffrent value resistor?I don't know who manufactured the leds.(if this matters).This is the second set of led's i burnt (i overheated the first set and melted them,this i know!)Any thoughts?
I have swapped several white LED's in place of the orange ones, without problems, but only so far in Kato locomotives. But I would not think you would have to change any resistors, as they would be needed for the original LED's. Did you install the new ones at the same polarity as the old ones? (Although, if you didn't, they would not have worked). Maybe someone else can come up with an explanation.
I have not had a problem with white LED's, but I am using DCC plug and play decoder boards. I have read on another list (sorry can't remeber which) that some stock light boards with directional lighting send the reverse voltage through the unlit LED i.e. when the loco is going forward, the front LED is lit, and the back is off, but the voltage is still being applied to the rear LED but with the wrong polarity. Normally, the stock LED's can handle the reverse voltage with no problem, but white LED's have a lower threshold for reverse voltage. I believe Kato uses extra components in their light boards (a diode) to block the reverse voltage, thus this may not be a problem with Kato locos. I have also read that not all white LED's are created equal. I have used those made by Chicago miniatures, purchased from Digi-Key.
In the past there have been posts that tell where and how to install these white LED's. Could someone please re-post this information. Thanks Mike
