North Bridge

Hi folks, Much of interest appears to have come out of my original enquiry! I've beefed up the wiring as suggested and that seems to have cured the problems originally outlined (i.e. NCE Power Cab not fully detecting short circuits). Thanks for all the really helpful suggestions. I also installed a PSX-1 circiut breaker and it is here I've come across another problem. Installed as it came (i.e. with no jumpers) it worked fine - i.e. power cut off when short occurred and then re-connected 2 seconds later. I decided to wire in the manual reset option by connecting a push-to-break switch across J7-1 and J7-2 as per the instructions. It is here that a problem has occurred. To test the effect, first I soldered 2 wires to J7-1 and J7-2 of the board. I held the other ends of these together and then created a short (coin across the rails). The power output LED went out and the short detected LED D6 came on - all as it should. When I separated the 2 wires, the power was also reset as it should. I also tested my switch to ensure it was of the push to break variety (that's OK). I then wired in the switch itself. When a short was created, power was cut off OK (i.e. LED D6 illuminated). However, when the swith was pressed (i.e. circuit across J7-1 and J7-2 now open), LED D6 stays on (and power output LED off)! The only way I can cancel the short is to disconnect mains power and turn on at the mains again. I've since disconnected the push to make switch - in effect restoring the factory configuration, and still, when a short occurs (i.e. J7-1 to J7-2 should be open), power does not restore after 2 seconds - D6 just stays on all the time. Clearly, things are not now working as they should..... I tried re-setting all CVs to factory values (i.e. CV63 to 42) and the problem still persists (though there doesn't appear to be a CV controlling this function anyway - just trying to exclude all potential causes). Can anyone offer any suggestions? I can't see that I've done anything incorrectly - is it possible that my PSX-1 may have a fault? Many thanks in anticipation. Karl Crowther

Hi Kev, Just the one connection for each wire of the bus through D connector (all soldered connections!). I did wonder if doubling up might help, so that answers that question, thanks. In a way, this is what I did when I made an additional (temporary), direct connection of the bus wires across the 2 boards (which seemed to do the trick as mentioned in my most recent post). I think I've identified two further issues with the point crossing/polarity wiring. After looking at my stock of wire, I may have used something like 8/0.2 and not 16/0.2, so perhaps this wire is inadequate. Also, two of the points are split across the baseboard join. This means that the wire from the switch takes quite a lengthy/circuitous route to the Tortoise - i.e. via the between board D connector and its associated wiring loom. Have ordered some 16/0.2 and need to look at ways I can minimise the length of these conenctions as much as possible. Hopefully the PSX-1 that I've just ordered will help set things in order as well, and save my Power cab from further abuse! A photo showing underside of Baseboard 1 is attached, if that's any help.However, note that this was taken before the wiring loom/D connector to the second board had been installed. Thanks once again. Karl

Evening all, Just connected power bus on both boards directly with lighting cable (by-passing D-connector and wiring loom connecting the two - wasn't excessively over-generous in length). Second board now cuts out with coin test on all sections of track (which didn't happen previously). When running 'wrong road' into a point crossing, there's now a very momentary buzz from the power panel and then it cuts out as it should (whereas previoulsy, the buzzing just continued). Don't know if the split second delay will be a problem, but intend to try a separate cut-out as suggested (I gather the PSX-1 is the one to use). That said, one point for some reason still fails to trip the cut-out. Need to turn baseboards over at some point and investigate more fully. Success of sorts and now hopefully have a way forward. Thanks to all, Karl

Hi, Thanks all for further advice. I was wondering if a separate cut-out device would help, something I will look into. I can also foresee an issue with length of wiring from point crossings to Tortoise switch needing to be as short as possible (i've used something like 16/0.2 wire for these connections and all droppers from rails). Having done a bit more checking, I now find that all tracks on the second of the 2 boards produce 'buzzing' with the coin short test, rather than correct shut-down of the Power Cab. This is the 'second' board in that it's the other one that the Power Cab feeds into. Coincidentally, all points are on this second board. On the 'first' board, all tracks cut out correctly with the coin test. Potentially it therefore may be more of an issue of how the 2 boards are wired together (though I think I used the same cable as the main BUS). Best way to test will be to wire the 2 board bus wires together with another, temporary connection, as short as possible, and see if this cures the problem. Thannks to you all Karl

Hi Kev, Susie, Thanks for your suggestions. Funnily enough, after posting I did begin to wonder if it was a wiring issue. I've tested all sections of track on the layout and there are a couple of sections (not on points) where the DCC does not trip with a coin between the rails (I get the buzzing as previously described). This does not seem to correspond with distance from the input (so probably not a straightforward relationship with distance). Each board is 3'6" long and I think the main power bus was 3A multicore lighting wire, with 1A droppers from the rails. I don't know if the main bus could be simply 'doubled up' and more droppers run from point crossings and rails on sections of track that don't trip-out correctly at present (potentially also using both switches in the Tortoise). Or perhaps a complete re-wire using something like 13A cable for the main bus? Thanks Karl

Hello all, I have a query about the short circuit protection for the NCE Power Cab that I am hoping that someone can help me answer. I have tested the short circuit protection by placing a coin across the rails and the power cuts out as one would expect (i.e. there's a 'click' from the power panel and the display on the throttle unit 'flashes' and then re-sets itself). However, something 'strange' happens when a loco approcaches a point set for the wrong route. Clearly, when a loco reaches the crossing (set to the wrong polarity), one would expect a short circuit to result and the system to respond accordingly and shut off power. When this happens in practice, the loco does indeed stop. However, this is accompanied by a loud and quite alarming buzzing sound emanating from the NCE Power Panel. Also, there is no 'flash' on the display screen, which continues to show what was there prior to the short occurring. Apart from the obvious 'panic' on the part of operator when this happens (usual gut reaction is to grab the loco before something awful happens to the chip - not really helpful on an exhibition layout!), I am wondering if this is what should happen? My points are built from C&L components, with the crossing polarity being switched through a Tortoise motor.I asked someone using NCE Power cab about this at a show, and he said the power cut out on his system in the same way as when a coin was placed across the rails - he even kindly demonstrated this to show it was the case. I am wondering if the above affect is something to do with the sensitivity of overload protection circuit on my system, and whether it is possible to adjust it? Can anyone offer any suggestions? Also I am wondering whether an additional circiut breaker is recommended for the basic NCE Power Cab, or whether the in-built one is sufficient? My layout is only 7 feet long and just 2 boards. I know you can get circuit breakers to supply multiple power districts, but I'm happy with just the one supply given the small size of layout. Hope someone can help/advise? Many thanks Karl Crowther

Hi Paul, Thanks for your advice, will try and seek out a copy of the book. Have already been studying photos on your website - what a fantastic resource! Cheers Karl:D

Hi Mark, Yes, it would appear that there are a pair at Chinnor. Thanks for the advice. Could always pursue as a last resort. Kind regards Karl

Hi folks, I am having a go at modelling a standard BR ferry van using the old Hornby model as a basis. I have heard it rumoured that the body moulding on this model is 1mm too narrow. However, I've found a scale drawing of the van in Don Rowland's "British Railways Wagons - the First Half Million" (Leopard - ISBN 0 7529 0378 0). From the dimensions provided in that, I've calculated that the external body width (excluding the doors), should be 30mm (in 4mm scale). The width of the body moulding agrees precisely with that dimension and therefore appears to be spot-on. Can anyone shed any light on the true situation? Thanks Karl:(