Hello. I purchased an n scale Athearn f45 with factory installed DCC and sound. I love this loco. It is a smooth operator and the sound is excellent. I want to install a roof beacon to make it more prototypical, but I came to find out the factory installed decoder does not support additional light functions. I found a beacon simulator with built in resistor but it requires its power from the track pickups. Has anyone does this? I have done many hardwired lighting features, but it was always to a dedicated soldering pad on a multi function decoder... just looking for some tips or advice from someone who may have already been down this road. Plenty of room under the shell for the simulator and wires, but never attempted to wire anything to power pick ups....As always, thank you in advance.
Is a roof beacon on both directions? If not you could probably piggy back on the front headlight leads. It shouldn't overload the decoder if it is an led
That is a very interesting idea.... I may have to try it....
What is the specific current draw for the beacon module that is listed in its data sheet or documentation? This includes the circuit that makes the beacon appear to 'circle' or flash.
Add this to the consumption of the headlight, in parallel, to determine the expected current through the relevant part of the decoder circuitry. Someone here can probably tell you what the max safe current for that particular decoder is.
It does occur to me that, probably with more trouble than it's worth, you could arrange simple track power to the module (in DCC the power at the track pickups is always on) with the appropriate dropping resistor, and use a voltage or current-sensing relay from one or more of the existing light circuits -- even something as crude as a photo detector reading actual light activation -- to turn the beacon on or off. If for example you were to require both "a" headlight input and Voltage to the motor above what is set for minimum speed, the beacon would only light when the locomotive started to move, but not if the locomotive is 'consisted' or in trail (with its lights off).