I aquired a pair of speaker-chip sets for a coulpe of RDCs a while back. The HO Lifelike PK1 was a doddle, runs and sounds great.
The N gauge Koto is causing a few problems, mainly with the cab circuit boards to which the LEDs are attached and powered down either side of the car, reversing as the feed is reversed. The letters DCC can be seen on a track that seems to be go between the LED pins from the right pickup across to the left only to stop short at a hole.
With the three wires in one hand and the iron in the other I thought, I've got a problem, the pickups ,motor & speaker are easy but how to wire a board, with built in resistor, a cap & may be a couple of diodes and get it right without making a mess of it.
If there's anyone, who has DCCed one, or had one stripped down (it's fun, but I would'nt try it as a first- off) for some other reason and can maybe shed some light HELP. I ain't gonna be beat and I ain't going to put this en back to DC.
Thanks for any idears
pick
I put DC in one a while ago using the Digitrax decoder. The leds on it were backwards, or something, if I remember right, but I was able to switch the wires around to get it right. That's not relevant for your problem. What is relevant is that being a lazy packrat I happen to have one of the original Kato board in my paws right now! I will take a look at it and get back to you....
Jeff But it's a dry heat!
OK, I think I've got it. You'll want to go carefully, and maybe use a meter to make sure I'm seeing right.
I am going to look at the board from the bottom, with 'DCC orented so that it reads correctly to make it clear what I am talking about.
There are two little screws in the board. Take the left one out, and put it back in the hole just to the left of the D. Just take the right one out. Remove the brown component at the top, which I am guessing is a capacitor. Remove the contact strips that were under the board (that may mean snipping them off, I don't remember what's under there, and I don't want to take mine apart). Hook the common from the decoder to the pad where the left contact strip (looking at the bottom) was, in other words the strip that the resistor is on. Hook one of the control lines to the circle just just below the place where you removed the first screw is (on mine that's just left of a silkscreened 'Y'. The other control to the other contact strip. I'm sure no matter which way you hook them up it will be wrong at first.
The only thing I am a little unhappy about is that the resistor looks to be only 270 Ohms. I would be happier with double that, or a bit more. You could probably remove it, and put another in, if you happen to have a surface mount laying around. You might be able to jumper an axial resisot in with a couple little wires to the topside. Maybe leave it at first, and see what you get....
Please let me know if this makes sense, and if it works!
I believe the Digitrax DN122K2 is a drop-in replacement for the N scale RDC. Has new LED boards and all.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
davidmbedard wrote:DN123K2....the DN122K2 doesnt exsist....David B
DN123K2....the DN122K2 doesnt exsist....
David B
You mean this one: http://www.digitrax.com/prd_mobdec_dn122k2.php
rrinker wrote: davidmbedard wrote: DN123K2....the DN122K2 doesnt exsist....David B You mean this one: http://www.digitrax.com/prd_mobdec_dn122k2.php --Randy
davidmbedard wrote: DN123K2....the DN122K2 doesnt exsist....David B
That's what I used (though I can't say for sure what the number was). The light colors were backwards, so I had to swap the wires to the light boards. It was a bit of a pain to install. I think the poster here is trying to hardwire a sound decoder, if I read right.
Here is a link with pics. He left the cap on. He also burned out his LEDs. That may be due to the resistor value I pointed out. It think the cap can go, since it is only across one of the LEDs.
Edit: uhhhh, the link:
http://lsvedberg.se/rail/index_files/Page2767.htm
Wow, did'nt mean to let the cat out, knew somebody had done one. Thanks Jeff,Randy & David, for the feedback. The link to the instalation is great, are there any more of them about, feel a bit left out over here.
As I said, I fitted a customised Esu 3.5 in the HO PK1 and will be using a Micro in the N gauge with the windows tinted to hide the decoder as it's narrower but a bit longer than a Digi and to make room for the speaker. I thought the resister would need changing because of the volt diference, the white and yellow wire are ok, and now thanks to you lads there's a place for blue en, the rest will be a piece a cake. The next one will be a Concor Huson
Thank again lads,
Vail and Southwestern RR wrote:Here is a link with pics. He left the cap on. He also burned out his LEDs. That may be due to the resistor value I pointed out. It think the cap can go, since it is only across one of the LEDs.Edit: uhhhh, the link:http://lsvedberg.se/rail/index_files/Page2767.htm
Looking at his pictures of the LED boards, I can see why they burned out. That's only a 270 ohm resistor in there. Assuming 2.1 volt drop for a color LED, at 14 volts that's runnign the led on almost 45ma, and even on 12v it's almost 37ma. Both may be over spec for a small surface-mount LED, 45ma is over the limit even for most big 3mm LEDs. A 270 ohm resistor is fine for DC, where you probably never apply more than 8 volts before the thing is rocketing like a missile .
rrinker wrote: Vail and Southwestern RR wrote: Here is a link with pics. He left the cap on. He also burned out his LEDs. That may be due to the resistor value I pointed out. It think the cap can go, since it is only across one of the LEDs.Edit: uhhhh, the link:http://lsvedberg.se/rail/index_files/Page2767.htm Looking at his pictures of the LED boards, I can see why they burned out. That's only a 270 ohm resistor in there. Assuming 2.1 volt drop for a color LED, at 14 volts that's runnign the led on almost 45ma, and even on 12v it's almost 37ma. Both may be over spec for a small surface-mount LED, 45ma is over the limit even for most big 3mm LEDs. A 270 ohm resistor is fine for DC, where you probably never apply more than 8 volts before the thing is rocketing like a missile . --Randy
Vail and Southwestern RR wrote: Here is a link with pics. He left the cap on. He also burned out his LEDs. That may be due to the resistor value I pointed out. It think the cap can go, since it is only across one of the LEDs.Edit: uhhhh, the link:http://lsvedberg.se/rail/index_files/Page2767.htm
Hence what I said before:
The only thing I am a little unhappy about is that the resistor looks to be only 270 Ohms. I would be happier with double that, or a bit more. You could probably remove it, and put another in, if you happen to have a surface mount laying around. You might be able to jumper an axial resisot in with a couple little wires to the topside.