I have a pair of Proto 2000 Alco PA locos which are DCC Ready.
I am going to install NCE D13SRP decoders which have 8-pin plugs to insert into the factory installed circuit board after removing the 8-pin DC plug.
Simple enough. But the problem is the lighting.
The upper incandescent bulb serves as a Mars light, and the flashing effect is created by alternating blinking lights on this 3 wire bulb which is 12 volts.
The lower incandescent bulb serves as the headlight, and it is a 2 wire 1.5 volt bulb.
An old thread on this forum indicates that the Mars light effect will be lost when a DCC decoder is installed.
http://cs.trains.com/mrr/f/744/t/132505.aspx
Would it simply make more sense to install LEDs since the D13SRP can be programmed to simulate the Mars lighting effect?
Rich
Alton Junction
Rich,
That's what I did.
The bulbs look better to some. You could wire the odd Mars light bulb like a set of ditchlights and get it to work -- maybe. Can't remember what the milliamp limit is on the NCE outputs right now, but if less than what it's rated for that could work.
Just seemed like a lot of hassle, then the bulb could burn out and I'd have to replace it anyway, so I went with the LEDs instead.
Mike Lehman
Urbana, IL
Thanks, Mike.
The function outputs on the D13SRP are rated at 40mA each if used with incandescent bulbs.
I'd just about bet that bulb is more than 40ma. Could put resistors in the leads and try stepping things down some, but not sure how much that would cut the light at the same time. They'd have to be 1/2 watt resistors, too, but there's plenty of room in that PA shell.
All in all, just easier with an LED. And you get several variants of the light to choose from on the NCE decoder if the Mars light version doesn't quite do it for you. IMO, NCE's effect is pretty good with LEDs.
Yes, any decent decoder can do a better Mars light effect than the stock circuit and dual filament light bulb.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker Yes, any decent decoder can do a better Mars light effect than the stock circuit and dual filament light bulb.
True. In the case of the P2K PA, it was really pretty darn good as analog, though, so I suspect there's a lot of interest in trying to keep it when converting to DCC. But the LED is just so much easier.
The last thing that I need to do is to fry the function output with a high inrush incandescent.
I will go with LEDs.
What I find weird is that the headlight is a 1.5 volt incandescent and the Mars light is a 12 volt incandescent.
Actually, Like Like uses a lot of 1.5 volt bulbs. I guess the Mars light, three wire, needs more voltage to alternate those filaments.
Mike, did you use 5mm LEDs or 3mm LEDs on your PAs?
With the incandescents, the Mars light is larger than the headlight.
I think I used 3mm as that's what I had on hand back then. A 5mm one would probably be just about right for the Mars light, I'd think.
mlehman Rich, I think I used 3mm as that's what I had on hand back then. A 5mm one would probably be just about right for the Mars light, I'd think.
I am thinking about using a 5mm LED for the Mars light and a 3mm LED for the headlight.
Anybody have any thoughts on Sunny White versus Golden White?
Golden white suits the era better. I used golden white LEDs in all my locos (all first gen diesels, I model the 50's).
rrinker Golden white suits the era better. I used golden white LEDs in all my locos (all first gen diesels, I model the 50's). --Randy
Yeah, sunny white would be like themore modern sealed beam headlights. Now, some first gen diesels were retrofited, most certainly, so if you model a later era but some of those old units were still running, they may have had upgraded lights and the sunny hwite would be a better option.
The golden whites are more like the original headlights which were like steam loco ones, a reflector with a bulb in the middle, usuaully ran on about 32 volts.
mlehman Rich, That's what I did. The bulbs look better to some. You could wire the odd Mars light bulb like a set of ditchlights and get it to work -- maybe. Can't remember what the milliamp limit is on the NCE outputs right now, but if less than what it's rated for that could work. Just seemed like a lot of hassle, then the bulb could burn out and I'd have to replace it anyway, so I went with the LEDs instead.
I found my PA's performed better by scrapping the factory board altogether and wiring everything straight to the decoder. I've found that with most any engine that has an excessive amount of components on the DC board. Just taking up wasted space with components that aren't even needed.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Thanks, Mark. I am reluctant to do that but only because I have the plug and play D13SRP decoders ready to go.
I could be wrong, but I seem to recall that dual filament bulb, when used on DC had one filament that stayed on and the second filament flashed on and off giving the illusion that it was a "moving" light.
I wired everything to the new decoder. I assigned the Mars light to F1 (Output 3).
Mark R. I found my PA's performed better by scrapping the factory board altogether and wiring everything straight to the decoder. I've found that with most any engine that has an excessive amount of components on the DC board. Just taking up wasted space with components that aren't even needed. Mark.
Same here!
Karl
NCE über alles!
So everyone bypasses the DC board and hard wires the decoder.
Nuts, maybe I should use the D13SR instead of the D13SRP.
Just unsolder / cut the plug off the wires .... instant D13SR.
Mark, sorry to press the issue, but if I have the D13SRP and the DC board has the 8-pin connector for the plug, what is the harm in just plugging it in?
No harm at all, but .... all that extra circuitry on the board also draws off the decoder and can also affect the BEMF if the decoder is so equipped. It's just been my experience that an engine runs much better without having been fed through those extra resistors, diodes, choke coils and capacitors. None of it is needed once you install a decoder, why feed everything through it.
I don't recall which engines they were, but I've had a few of them that no matter how much I tweaked the decoder, they just did not run well. Ran slower than everything else and the speed steps were jerky .... you could just tell something wasn't right. Trashed the factory board and they ran like completely different engines. May have even been MY PA's, I honestly don't remember now.
Thanks, Mark. Interesting stuff, a lot to consider. If I have problems or issues, I can always start over and scrap the DC board and remove the plug on the decoder.
When installing decoders on DCC Ready locos, do you always remove the factory board and hard wire?
richhotrain Thanks, Mark. Interesting stuff, a lot to consider. If I have problems or issues, I can always start over and scrap the DC board and remove the plug on the decoder. When installing decoders on DCC Ready locos, do you always remove the factory board and hard wire? Rich
Personally, I do. That way I know I'm dealing strictly with the decoder and the drive and not something else in between. For engines that have the Atlas style board, it's simple - just use a decoder of the same design and it's a drop in replacement.
Mark, thanks for that follow up.
I have usually left the factory boards in place except where the DCC decoder is a drop in replacement like on the Athearn Genesis.
Are any hard wire installations easier or harder than others? I assume so.
The more difficult ones are earlier runs before DCC, but even those are rather straight-forward. On older engines (like Athearn blue box) the important thing is that you make sure both brushes on the motor are isolated from the frame. Aside from lighting, it's always gray and orange wires to the motor and red and black wires to the trucks. Pretty basic really.
Even when the board appears to support plugging in a decoder, I always consult the usual online resources. Some of what was sold as DCC Ready wasn't quite so ready. In fact, you can blow a decoder by just plugging into the board in a few cases, IIRC. I remember my P1K RDC and a few others needed traces cut, etc. Sometimes it's easier to leave the factory board to preserve a lighting arrangement, etc, so I leave it. Most of the time, I yank the factory board. for the same reasons Mark was explaining.
Mike, what did you do for your Proto 2000 PA? Hard wire or plug in?
If it isn't truly DCC Ready, hard wiring the decoder instead of plugging it into the socket on the DC board isn't going to save it from getting fried.
P.S. Mike, I PM'd you on another issue.
Pulled them out of the drawer just to be certain what I was talking about. Thought I'd pulled the boards, but maybe I was only wishing I did, as least on the A unit. At least my memory was right about the LEDs being 3 mm.This applies only to the later run PA/PB with the better, low amp motor for anyone else reading later...
The B unit was just a plug in, with the decoder nested in the little cubby hole the opposite end from the board. Looks straightforward.
The A unit is, well, complicated. I did plug it in with the 8 pin. I alos scabbed the Output 3/F1 wire to the Mars light onto the decoder. And I'm not real sure that I did hack something else, but it wasn't obvious to me at this late hour. So would be well worth consulting several of the web reference DCC conversion websites to see what's said about that.
Looking at the nose, I managed to shoehorn the two 3mm LEDs in behind the light tubes. It's tight for the lower one. For the upper one with the bigger lens, I used a piece of shrink tubing to "fatten" the LED to fit the bigger hole the bulb occupied there.
richhotrainIf it isn't truly DCC Ready, hard wiring the decoder instead of plugging it into the socket on the DC board isn't going to save it from getting fried.
Maybe. If the Motor isn't isolatede, yeah, things will still be crispy regardless. But there's a whoie lot of other wiring that could burn out F outputs, etc. Whole board isn't toast, but enough to irritate you. I suspect that motor isolation was a ley part of this early theory/defoinitiomn of what DCC ready requires. I pretty much count on my own skills to look locos over and decide what's needed, so I look to confirm some identifiable isolation. If noit, the meter comes out and I try to confirm Yes or No. I then turn to deeper research if it's not clear what to do. Some time, there are several option, another place where looking around can yield some benefitsv .
On ones I did, I left the board in place, but I pulled all the black plastic clips and removed the wires and connected them directly to the decoder. The factory board is 100% bypassed, but if I would ever need to make it a pure DC loco again I could just cut the wires and reconnect them to the factory board with the clips.
You may find some install instructions that have you add one of the extra function wires, purple or green, to the one spot on the 8 pin plug that normally is a no connection - the blank spot is what makes it safe to plug the 8 pin connector in backwards - nothing fried, but it won;t run right either. Life Like connected that pin of the 8 pin socket on the factory board to the mars light circuit on the board - so if you add one of the extra function wires you can retain the stock setup and trigger the Mars light. But - I still say most any decoder does a better job of simulating the Mars light than the stock two filament bulb and circuit.