[goedel]

Sorry to tag along on the end of this thread - I have similar concerns about voltage with my new Roco digital set. It's the first Roco N scale DCC set and so uses their standard H0 transformer at 16V AC, but I've heard that it can spike much higher than this and I'm pretty sure my locomotive bulbs look rather brighter than they did on 12V DC, so I've ordered some diodes and hopefully 16V will be closer to 11-12V in a few days time. (Thanks very much for sharing that advice with the forum Richard!)

Does anyone know from experience how well behaved the Roco digital system is on the voltage front?

I do know someone with an oscilloscope so it might be fun to look into the dark heart of the DCC signal...

I know the Roco system is not the most sophisticated system but as a start set (article number 21200 - there is a thread I did about it somewhere...) it is great value and perfect for a first adventure into DCC. When I know what I want from DCC I think I'll move upmarket to something more capable, although the ergonomics of the multiMAUS are great.

 

[goedel]

QUOTE (Brian Considine @ 5 May 2008, 07:19) <{POST_SNAPBACK}>AFAIK the Roco system is very stable. The locomotive bulbs will look much brighter than on 12v DC as they are getting full voltage all the time. If you cannot "dim" the lights with the decoder CV settings then you could replace the bulbs with 24v ones. The other possibility would be to replace the power transformer with, say a 12v one. Don't forget that you can use the Mulimaus as a second controller with most systems when you upgrade.

Thanks for that advice Brian, I think the Roco system will work with any decent i.e. stable transformer so I could find a smaller one but in the mean time it made sense to calm the Roco system down to about 12 V from 16 to reduce the strain on decoders etc. Therefore I ordered some 1N4004 rectifier diodes (100 for £1 from eBay) and some 5A terminal blocks (overkill for N scale currents!! 10 twelve ways for £1.65 on eBay again).

Total cost inc. P&P was £4.60 and arrived within two days from Quasar Components eBay shop - highly recommended and much cheaper than Maplin etc.

It was then just a case of cutting the track supply wires, splitting the ends and stripping back the covers and screwing into the terminal blocks with the diodes arranged in the the pattern Richard advises. In the end I got carried away and put 7 diodes in so the voltage is probably about 16 - 0.7 x 7 = 11.1 V which is still enough for my N scale locomotives it seems, and it will be dead easy to change it to 6 or 5 if needed in future, as my Roco system is basically working as a test and programming track at the moment. Come to mention it one or two bulbs looked a tad dull, but of course the LEDs were unaffected!

(Note: wiring diagram on right is for 6 diodes

Useful advice - for multicore copper wire then soldering the ends first can make the connection surer when you screw the wire down - just twisting the cores together is okay if you don't make any mistakes and don't need to move the wire afterwards by which time the end will be a mess...

...I hope that someone at some point finds this useful!