I’ve just added a DH123 decoder to a Backmann On30 Trolley. All works well, including the forward and reverse headlights (LEDs). However, the interior lighting uses to small incandecent bulbs, and I have no more function outputs to connect them to. Could I connect them rite to the track for power? At 15 volts they used 125ma (measured with my meter and a few batteries). I’m using a Digitrax Zephyr to control the unit. I think the Zephyr maxes out at 1.5 amps. Will connecting these lamps directly to track power damage the Zephyr or effect the signal adversly (assuming the Trolley with all lighting is well within the max current draw of the Zephyr)? Or should I just purchase a decoder with more function outputs (which would be far cheaper than buying a new Zephyr)?
you can run them off straight track powwer, or if you want to control them, digitrax makes a one function, function only decoder for about ten bucks, the FL1.
Good to see another serious trolley modeller. Two other possibilities:
Replace the incandescent bulbs with LEDs. They will draw far less current. The light from a LED is very directional, though, so you might want to take a look at how they are mounted and whether you can “scatter” the light by bouncing it off the trolley roof, etc.
Use a small magnetic reed switch to turn the lights on and off. These are available at 2 for a dollar online. You control them with a magnetic “wand” when you want to turn on and off the lights.
The Digitrax single-function “light” decoder is a TL1. Its list price from Digitrax is $18.95.
One other option: If you want to control the interior lights, you could always swap out the DH123 for DH163. If you haven’t cut the excess wiring off the DH123’s harness, it would simply be a matter of unplugging the 123 and plugging in the 163.
I would be more concerned about the voltage the Zephyr is putting on the rails. Some DCC systems are set the factory (Lenz) to put out 17.5V. This would fry a 15 volt bulb pretty quick. At the club we lowered the power output of the DCC uint to 13.5V. This way 15 volt bulbs will last forever.
No, in fact at our club it is a requirement to have at least one lamp on the locomotive be connected directly to track power. That way one can tell if an electrical problem is power getting to the locomotive (this bulb is not lit), or if it is internal to the decoder et.al…