Hey everyone! Hope all is well. I just got a few pieces in and a schematic or two. My Paragon 3 decoder of course failed me and I want to replace with this N18 decoder and adapter. I am looking at the wiring for the Proprietary BLI Engine and had a few questions maybe some of you could help out with. First off here is the pin out and photos of the set up: I have most of it it figured out. Just was wondering what the 3.3V.. Is that Common or Gnd. Because Gnd is next to it. I've been reading to use GND for common. Also Wondering If I need to incorporate Resistors for these LEDS! This is a custom job! Would be great to get this thing back on the rails! Cheers! Take care!
Decoders typically run LEDs with a common supply (3.3V), used to supply current for LEDs to be sinked by the decoder on the respective pins. The decoder creates/regulates the 3.3V output from track power. So, generally, function LEDs have their anodes tied to 3.3V, and their cathodes tied to the relevant function output of the decoder. On a schematic diode symbol, the anode is the broad side of the triangle, and the cathode is the pointy side of the triangle, with a bar across it ("CATy bar the door" is how I was taught to remember it.)
Thanks for the info. However, I believe you made it more confusing for me. haha I am familiar with anode and cathode. Not sure what you are saying here. The question was whether I need to use GND for a common or the 3.3 For the common. If I had to guess you mean to say use 3.3v for the common? Thanks for the reply. Lets see if we can straighten this out!
The common is the 3.3v for the LEDs. The ground side will be through the function pad on the decoder as Andy mentioned. The ground pad on there is there if you need a ground for something other than the LEDs such as a keep-alive. You need/want resistors on the LEDs, either on the decoder grounding side or the common power side. Sumner
Appreciate the clarification. Lets confirm this too. Looking at the third picture with the led light board installed. it has a ground pad that DOES have a wire attached to which feeds into the harness. You are saying to not use this wire unless I have a keep alive correct ? Thanks!
..... Or you had something else that needs a ground, don't know what that would be. You do not want to use it for the LEDs that are controlled by functions. If you did have an LED that wasn't going to be controlled by the decoder then you could connect one side to that ground and the other side to the common 3.3v and add a resistor not sure why you would want to do that but one could do that. Sumner
I don't intend to do that at all. I just want to make sure I wire it up right. To clarify though. With this install I will not be using that black wire on the ground pad. I can remove it correct ? This is what the locomotive is already equipped with: Head Light/Rear Light Ditch Light Cab Light 4 Light Functions total. Hence why I was asking which was the common. So if 3.3 is the common I shouldn't need resistors if controlled by decoder ? It is a Tsunami 2 N18. If so I wonder which size hehe Thanks
Is there a reason you want to get rid of the ground wire? Not sure what some of the other wiring on that board does so hate to guess on my part. 3.3 v can give some LEDs a very short life or be very bright. You should use a resistor either by one you put in place or if the board has ones for the circuits you put the LEDs on. From one set of instructions I found looks like some boards do have resistors and some don't (look down a ways)... https://soundtraxx.com/content/Reference/Manuals/Tsunami2/Installation-Guide.pdf I have no idea what the board you are using has. Should be with the documentation for the board. Since I've had no experience with Tsuanami decoders I think I'm at the end of my help. Hopefully someone will take over unless you find the help in the instructions, it should be there. Sumner
Current damage in an LED (or other electronics) is caused by excessive heat, which can be managed by altering the duty cycle of a pulse-width-modulated (PWM) output waveform driving the LED. This works by varying the relative on-time vs off-time within a given repeating, invisibly short interval. This is especially true for various lighting special effects (e.g. mars lights, dimming lights, etc.) options the decoder may provide. And it may not apply to all of a decoder's light outputs. Thus no external resistor may be needed. But verify this is the case for your decoder output before depending upon it. FYI, PWM is also how the decoder varies the power to the motor in order to control the locomotive speed. As always, RTFM (Read the Fine Manual.)
