The Hobbytrain BR 363 Cottbus, converted to DCC with cab driver light and capacitors.
Original
This little shunting locomotive is part of the DB V60 family, this one belongs to the 363 series of the DBAG. There are many of those small (yet aging) Diesel locomotives still in service. This black livery model is in service at the Cottbus workshop (see DB article in English).
Model
This model, part no 249085 is another Hobbytrain production for the Conrad Electronics chain of electronics hardware store in Germany. It was available for less than 50€ a while ago. I liked the black livery, sometimes with only DB trains your layout can easily turn out all redish. Realistic for Germany? Maybe, but not very fun!
Conversion details
I had converted this model a while ago for DCC, using the onbard NEM651 plug. But I wasn’t satisfied with the result (the model is small, and as often in N scale, power feeding wasn’t good).
So I decided to remove the NEM651 plugin to leave some room, and instead solder some custom improvements to the engine and decoder:
- An SMD Led-based light for the driving cab.
- Added capacitors to improve power feeding (4x47uF SMD capacitors)
Cab light in place with LED
Cab light test
Light and capacitors in place
If you’ve been reading the blog often you know these are kind of standard DIY add-ons to my locomotives. The cab light test photo above shows the “raw” state. Meaning I have later dimmed the light (via decoder CV editing), and added some yellow paint on the LED to have the light look more natural (warmer).
Although the ESU LokPilot Micro v4 decoder does not have a SUSI interface per say, it has an output for light which I used for the cab lighting (the engine doesn’t have headlight and adding them would have been too hard). It also has an input to connected capacitors. Notwithstanding the absence of SUSI plug, both circuits (light and capacitors) are detailed in my article about using the SUSI interface here.
Conclusion
Now that’s better! With the added capacitors, the locomotive drives much more smoothly. The engine is finally usable as a shunting engine on switches and at slower speeds…which is kind of the point! And the cab light doesn’t hurt of course.
Speaking of CV light dimming, what to do if the PWM frequency gets so low that the blinking becomes visible?
Good question! Unfortunately, I’ve never had that problem so I don’t have a solution for you.
Dimming the lights – if it starts to flicker, change the resistors to larger values, and, if space, fit smoothing capacitor in the lighting circuit.
On the stay-alive capacitors, I recommend you experiment with Tantalums in comparison to the Ceramics. I’ve put ceramics (like in your photo) into a few small locos and they have some effect. But, I then was shown a performance graph for ceramic capacitors, which has an alarming drop-off in energy stored as the voltage approaches the rated value (16v). In the DCC stay-alive use, the voltage is somewhere up near 16v, depending on chosen track voltage, so the drop in energy stored is significant. In contrast, Tantalum capacitors have a flat performance line. I then did some experiments with Tantalums, ending with a “physical volume” comparison, and concluded that the Tantalums perform better at the same physical volume in the model.
Some more details of my work on http://nigelcliffe.blogspot.com
Hi Nigel, that’s a very interesting point! I did have trouble finding tantalums at first so I just went for the ceramics and kept going. I will for sure try tantalums and you have some very interesting posts on your blogs, nice job!
Pierre, Disqus has borked again (recommend you junk it and use something else for comments), and I just get the spinning disk of eternity in my browser. So that’s no more comments, sorry. (this posted via spare computer which I dont usually use)