Hello,
I currently have a DC N scale layout but will be upgrading to DCC in the near future.
The issue is that I'm about to install a pair of red SMD LEDs (or a single red LED and two fibre-optic cables) in the end coach of a rake to provide a pair of tail-lights. They will be connected to a resistor and a pair of diodes so that they will work on DC in both directions. I realise that their brightness will depend on the DC voltage but as I'm moving to DCC with a constant track voltage it doesn't matter.
More importantly I'm worried about possible flickering because of the DCC square wave signal or is the freqency too high for the human eye to notice? If the flicker is an issue then I shall add a capacitor to allow power to be provided continuously, but then I wonder if the capacitor will interfere with DCC?
Here is a proposed circuit diagram, the red and green lines represent opposite rail polarities:
The reason I ask is that because space is tight and I will have to modify the interior of the coach at one end then I want my design to be DCC compatible so that I don't have to make further modifications in future. The other option is to fit interior lighting to the coach (not a priority), and use this plastic light transmitter from Minitrix (66657), anyone have thoughts on this as an alternative?
(Obviously this only fits certain Minitrix coaches and I have several rakes of Roco ones so the SMD LED solution is still needed...)
Thanks,
Goedel
I currently have a DC N scale layout but will be upgrading to DCC in the near future.
The issue is that I'm about to install a pair of red SMD LEDs (or a single red LED and two fibre-optic cables) in the end coach of a rake to provide a pair of tail-lights. They will be connected to a resistor and a pair of diodes so that they will work on DC in both directions. I realise that their brightness will depend on the DC voltage but as I'm moving to DCC with a constant track voltage it doesn't matter.
More importantly I'm worried about possible flickering because of the DCC square wave signal or is the freqency too high for the human eye to notice? If the flicker is an issue then I shall add a capacitor to allow power to be provided continuously, but then I wonder if the capacitor will interfere with DCC?
Here is a proposed circuit diagram, the red and green lines represent opposite rail polarities:

The reason I ask is that because space is tight and I will have to modify the interior of the coach at one end then I want my design to be DCC compatible so that I don't have to make further modifications in future. The other option is to fit interior lighting to the coach (not a priority), and use this plastic light transmitter from Minitrix (66657), anyone have thoughts on this as an alternative?

(Obviously this only fits certain Minitrix coaches and I have several rakes of Roco ones so the SMD LED solution is still needed...)
Thanks,
Goedel