flashing ditch lights stop working after a few nminutes

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Using a DN144K and 1.5v bulbs with 300 ohm resistor. CVs are set correctly for alternating flash effect. When first activated, alternating flash effect works as advertised. After a few tries (I can't resist playing, and this is N), the light controlled by F2 stops operating, and shortly thereafter the light controlled by F1 stops. This makes me think the decoder must be overheating or oversomethinging on these 2 functions, but damned if I know what, which or why. Headlight LEDs have been replaced with 1.5 bulbs (LEDs are too dim--listening, Kato?), with rule 17 activated on reverse direction and thru F4; they seem to have no problem and work as advertised. Anybody got any suggestions? I'm stumped. Thanks for any input.

-- Larry Keller (kellers@rjsonline.net), February 09, 1999


Larry, I waited a bit on this one hoping someone in N or anyone using the DN144K would respond. This may help - may not. 1.5 v bulbs can have a 'cold' starting draw that's significantly above the rated 15-35ma. The lights may be shutting down due to a thermal overload. In HO with 1.5 volt bulbs I use a 560 ohm resistor and wire the lights to the frame ground (track voltage common) - giving 1/2 cycle burning. Another option might be to wire each light across two series 1N4148 diodes with the 300 ohm resistor as the sink. The bulbs would then have regulated voltage (semi) and the load on the funtion outputs would have greater saftey. I gather from your sequence that the bulbs etc. don't burn up as further actions through the functions are working. If this doesn't make sense - then contact Digitrax (which you should always do 1st).

-- Ed McCamey (emccamey@cheerful.com), March 24, 1999.

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