Tomix Type 500 Shinkansen DCC conversion

[Kiha66]

The capacitor should be in parallel with the led's, after the rectification from DCC to DC.  The resistor would be on one leg of the capacitor, preferably the positive one.  100 ohm should be more than fine for this application, the purpose of the resistor is just to dampen the current.  You could also throw in a diode so to to avoid the voltage drop when in power mode keeping the LEDs lit.  I'll try to draw up a diagram tomorrow, I think my attempts to describe the circuit in words are just confusing.  

Replace the Decoder +/- with lightboard +/- and this is what I mean.  
http://mrdccu.com/_Media/4_med.jpeg

Image from this guide on stay alives in DCC decoders
http://mrdccu.com/curriculum/stayin-alive.html
Also using these guides as a refrence
http://mrhpub.com/2013-03-mar/land/files/assets/basic-html/index.html#page43

http://www.members.optusnet.com.au/mainnorth/alive.htm

[gavino200]

10 hours ago, Kiha66 said:

The important thing to remember for choosing a capacitor is the voltage rating.  You want to make sure that the capacitor is rated for more than the voltage that the tracks put out.  16v is the minimum I would use on a DCC system.  Just make sure that the Capacitor is correctly attached to the polarity after the diode and you should be good to go.  Since there isn't a lot of power draw and this is just for antiflicker 470 should be ok.  With a resistance of 1k ohms that gives you a time constant of almost half a second. (time to 63% discharge).  Let me know if you have any questions.  

Also if you plan to have a lot of them or use a large capacitance then having a resistor on the charging side can be helpful to limit inrush current.  

 

 

Actually all decoders can take a keep alive, you just need to find the point after the diode bridge to add it.

 

These are the spec for the Capacitors I have:

 

20pcs Tantalum Capacitors 227E 25V 220uF Type E SMD 7343 Surface Mount

 

Looks like 220uF and 25 volts.

 

Not ideal? Should I get a lower voltage cap? I'm not concerned if I don't use these. And I'm not in a hurry. I'd rather find the optimal component and keep using it for this purpose as time goes by. What would you say would be the ideal capacitor for this situation - interior coach lights.

 

[gavino200]

I opened up the Kitty to get it running. Was surprised to find these weird black stickers? Anyone know what on earth these are? The package insert is all in Japanese and doesn't have a picture that explains this.

 

[gavino200]

On 2/3/2019 at 12:04 AM, chadbag said:

Got the rear cab car done on the Kitty-chan Shinkansen 500 (Tomix).  On this one I reversed the yellow and white wires as I wanted the forward and reverse to be backwards.  I also was able to fit the decoder under the power pickups after removing a small white rib.  The internal seats and stuff were different and there was not he same hidden space to hide the decoder.   I'll write it up in more detail, but it all works.  On this one I also had to clear bit 0 of CV36 to get the "forward" (when the train is "reverse") light to work.  I like these bipolar function decoders.

 

I'll go step by step with more pics in my full write-up I will do at some point.

 

 

 

Chad, I was planning on using a LaiDCC decoder for this installation. But it doesn't fit in this little pocket under the pickups. I see Dani just placed his in the passenger compartment. But after going to the trouble of placing all these little Hello Kitty stickers, I don't want to do that. I'm going to shelve the project for now. 

 

What decoder did you use here for the cab lights? Was it a tight fit? I'm going to wait and do the same way you did,  if you tell me that you'd do it the same way again if you could do it over. 

 

I may look for a different LED strip and change out the interior lights also. I described the problem in the Lighting project thread. In any case the hard part with the lighting was dissassembly of the car and soldering to the steel pars. Switching the actual strip should be easy. 

 

Edited March 3, 2019 by gavino200

[chadbag]

I used the NGDCC bipolar and yes I would do it again.   I need to see exactly how I did it (front and back were done differently so I need to double check and be at my computer, not my phone, to give a better answer.

[chadbag]

@gavino200

So I put the decoder under the pickups on the cab car that had a full passenger compartment (not the one you are showing).  The other car, with the frosted windows (the one you show in your pic) I just stuck in that room at the front of the compartment that you cannot really see from outside.   I might do it under the pickups in that car if I were to do it over, but I did that one first and did not think of it. The place under the pickups is the same in both cars.

 

In order to fit under the pickups, I removed that white rib that is sticking out into the room under the pickups to the left of that round pillar and the right of the front flat part.  There is room for the decoder I used, but just enough length (more than enough width).

 

I used the NGDCC DF11r6  but if I were to do it again I would use the NGDCC DF19x4bpss which is not quite as long by 0.5mm and slighty wider and taller, but which would seem to fit when eyeballing it.  I used the one I had 🙂     The reason I would switch is that the DF19x4bpss has 2 extra normal function outputs, besides the bipolar, so you can drive interior lighting on the same function decoder.    The DF19x4bpss is the one we have on order and are awaiting.

 

 

Edited March 4, 2019 by chadbag

[gavino200]

I wired up the cab lights using Chad's excellent method. It works great and I thoroughly recommend it. I'm very grateful as I don't think I would have come up with it myself. It's also very nice to use a bipolar decoder rather than messing with the light board. Bipolars are definitely the way forward.

 

NGDCC bipolar decoder http://www.snjpn.com/ngdcc/df19/df19x4bpss.htm

 

 

[chadbag]

How did you attach the black and red to the power bus strips?

[gavino200]

1 minute ago, chadbag said:

How did you attach the black and red to the power bus strips?

 

I soldered them to the underside of the metal pick-up strips/bars. A little tricky as the distance is short - about .5 and 1.0 cms. I soldered first to the strips. Then assembled everything, and marked the length of wire needed. Then disassembled, cut and soldered. Then reassembled. Then similar process for the LED wires. 

 

I used adhesive putty to hold the pieces together in a state of partial disassembly at various times. It really helps. I also used it to hold the decoder in place.

[chadbag]

How did you solder to the metal strips?   I could get solder to stick no matter how I fluxed it.  I soldered to the springs underneath.   

[gavino200]

1 hour ago, chadbag said:

How did you solder to the metal strips?   I could get solder to stick no matter how I fluxed it.  I soldered to the springs underneath.   

 

It wouldn't work for me either using regular goo type flux. But I remembered I had some liquid flux. I bought it a couple of years ago when I made a bit of a study out of soldering. I followed the advice of a guy who had a website all about soldering. The liquid solder was harder to use and didn't seem to have any advantage so I never really used it. 

 

But it's exactly the thing here. Just mark when you want to solder. Apply a drop of liquid flux. Touch the iron to it until it evaporates and then touch the solder to the strip. As if by magic it now works. Let me go see if there's a name still on the bottle. 

Edited March 15, 2019 by gavino200

[gavino200]

H&N Electronics

 

https://www.hnflux.com/

 

[cteno4]

May be a good old rosin flux. I like the thicker rosin liquid flux as you can paint it on easily on small parts and tighter places than trying to dap on the paste flux. The rosin flux almost always flows better than the paste rosin as well.

 

jeff

[Martijn Meerts]

I never use flux, not even on the brass World Kougei kits. I did use it at some point while building my own functional catenary, but even after cleaning, the residue ended up destroying the fine detail of pantographs on the European models.

 

So far, I've come across only 1 piece I could get soldered, but even using flux didn't help there. 

[cteno4]

But you are most likely using a rosin core solder, right.

 

jeff

[Martijn Meerts]

9 hours ago, cteno4 said:

But you are most likely using a rosin core solder, right.

 

jeff

 

Not sure it's rosin core, but there is a minimal amount of flux in it. I use this kind of solder for pretty much everything: https://www.almit.de/products/product.php?pid=2019

[cteno4]

Yep 3.5% flux, probably good stuff so works well. I had a great roll of solder for many years (it was on the large side) and it worked really well universally and the it ran out. I tried quite a few that did not do well a lot ofmthe time and finally got some good Kester and it’s nice! I’m curious to hear more on Gavin’s soldering and flux tests he did a while back.

 

jeff

[Martijn Meerts]

It has a bit of silver in it as well, and is more meant for soldering circuit boards and such, but it flows great, so I use it for pretty much everything. Bit more expensive, but well worth it.

 

[gavino200]

2 hours ago, cteno4 said:

Gavin’s soldering and flux tests he did a while back.

 

 

Ha. You give me too much credit. I just mean that I schooled myself a bit. I originally "learned" to solder by just playing around. I also didn't use flux at first but was using rosin core solder. But I felt that my results weren't what they could be. So I sought out a good educational source, read the theory and applied practical tips. 

 

I sort of get Martijn's frustration with resin. It's messy stuff if you use too much. I generally use my loupes to solder. I actually apply flux using a tiny Tamiya applicator stick or sometimes something smaller. Only a very tiny amount is necessary. I apply just enough flux under magnification and generally don't have any problems with excess flux. 

 

I don't know what these Tomix pickup strips are made of. They're a silver/chrome color and are quite thick. I've never encountered this kind of difficulty soldering before. I'm interested whether @Martijn Meerts has managed to solder specifically to these things without flux. For me, nothing worked AT ALL other than the liquid flux.

 

I did experiment with different types of solder at one stage. I was dissatisfied with lead-free solder. I tried various kinds - lead, no lead, silver, various different alloys etc. But I found that when I improved my technique I could use almost anything with good results.

Edited March 16, 2019 by gavino200

[chadbag]

I've been using Kester "44" 63/37 0.020" dia (thin).  Seems to work quite well for normal solder jobs.    But as @gavino200 said, that silver/chrome power bus i the Tomix Kitty-chan 500 would not take any solder even with paste flux and stuff.  I will be getting some of that liquid flux Gavin recommends.   I have a bottle of "Lötwasser" from Weller from when I lived in Germany.  But it seems to be more for non-electronic soldering and I am not sure it will be good for doing electronics.

 

I am going to getthe H/N stuff in liquid and gel format and some of their solid core solders.  We'll see how it works.

[Martijn Meerts]

I don't have the Hello Kitty 500, so I can't try it. Can't say for sure I have any other Tomix trains which have the same type of pickup strips. Of all the decoder installs I've done (well over 100 by now, all sorts of brands, old and new), I've not really come across one that I couldn't solder the wires to the pickup strips. The only problem I've had was soldering to the frame itself, solder just wouldn't stick. Any other known trains with the same power pickup? Maybe the 500 Evangelion, I'm guessing it's the same model?

 

Other than that, I don't use flux (or at least additional flux other than what's in the solder) on anything at all. Soldering to the track (Peco code 55 mainly), or soldering track pieces together hasn't been any issue. Soldering electronic components (I buy most occupancy detectors and such as kits and built them myself) haven't been a problem. Soldering the World Kougei brass kits has also not been much of a problem for the most part after some practice.

 

That said, I did spend quite a lot on a good soldering station. I used to have the cheaper ones, and those just annoyed me most of the time, soldering a wire to the track with those things didn't even work well. Soldering went from a major pain in the ass to something I don't mind doing at all.

 

[gavino200]

2 minutes ago, Martijn Meerts said:

Maybe the 500 Evangelion, I'm guessing it's the same model?

 

Agree. I bet it's the same. 

 

2 minutes ago, Martijn Meerts said:

 

That said, I did spend quite a lot on a good soldering station.

 

I could be wrong but I don't think this is soldering iron related. I've had zero difficulty soldering anything else. Also, the same iron was used with success in conjunction with the liquid flux as was used with failure without the LF.

 

But I'm curious, what kind of setup are you using? 

[Martijn Meerts]

I'll see if I can find the Evangelion, it's a bit of a mess up on the attic / train room..

 

I have a Weller wd2000m with a really small soldering iron and a pair of soldering tweezers which makes de-soldering SMD components real easy. I've had it for 13 years or so, and never had to replace anything yet, not even the tip.

[chadbag]

Just FYI:   I bought the HAKKO FX-888D station after futzing around with standard irons and what not for a long time with the RC/multirotor/guitar work and it has been a life saver.  Lot sof different size tips you can get for it.  It heats up very fast, and you can can set it for specific temperatures.  Under US$100 on Amazon.com.

[cteno4]

Just curious did you try to rough up the surface of the strip? Wondering if they put a coating on it that’s mucking up the soldering.

 

id say 95%+ of my soldering I just use rosin core solder and things are great. I only use external flux if I want to make sure I get a fast even flow or things like tinning lots of wires as adding a little flux can make it flow fast and even.

 

jeff