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Everything posted by Junctionmad

  1. Just in relation to ABC. You can get issues where metal wheels in the stock following the loco bridge the ABC track section and non ABC sections , causing errant behaviour and failure to stop. I’ve had to place very short insulated sections in between the two sections to prevent such issues , but it’s not a complete success , double heading ,carriage light pickups can all cause confusion
  2. Just by way of illustration. My friend has a large OO gauge fixed layout , 18by 12 , multiple levels all code 100 insulfrog it was DC with conventional isolating sections etc. He connected the dcc feed to the track and closed all the section /isolating switches dcc working fine now ( nce ) for several years is it best practice dcc wiring , god no. Does it work , absolutely dcc does not require u to do anything special if U don’t want to.
  3. No you just need the transistor circuit, per point , the capacitors can drive as many points as you need , the leds can be removed if not required hence you have a few jelly bean components per point to derive the advantage of low currents through the switches you do need a 2x transistor for each point
  4. All you ever need to know about CDUs. Near the end there’s a nice circuit that uses transistors to switch the CDU rather then the switches directly ( choice number 9) http://www.talkingelectronics.com/projects/75 Model Railway Projects/75 Model Railway Projects.html#Points PartB quite a nice circuit as it uses standard toggles and provides mimic panel leds as well
  5. Shameless self promotion you could build my dcc dropper boards, Optional dcc indicator led supported £3.50 each plus P&P ( not commercial , just covering costs ) simple to build connectors included etc.
  6. While there is definitely some difference in illumination , in many cases it’s irelevant ( mimics etc ) for example for blue , red, green and yellow I use 1k8 on 5V. Works fine
  7. Or use a CDU design that doesn’t pass the activation current through the switch ! There are several published designs where a transistor switches the output of the CDU and the switch simply switches the transistor. This removes the arcing and high current pulses from the switch
  8. Or use a CDU design that doesn’t pass the activation current through the switch !
  9. It’s such a corner case it’s around the corner in real life electronics with similar leds , one resistor will “ work” Yes it has certain specific drawbacks but in practice it actually works. Yes it’s not a Recommended approach but for leds from the same family operating well into their safe current zone it will work and no I’m not recommending it
  10. I have done this also , here Les the fusion 360 cad , I just finished the software
  11. If you look at the characteristic curves of leds the VF rises with current , Hence your sceanario will not occur
  12. My experience is I don’t rely on the peco wires and i solder on my own I would always recommend bonding the switch blades to the stock rail and switching the frog as the optimum approach, but as has been said the points will work out of the box also.
  13. If you points and signals are electrically operates then , other then having a particular interest , there no advantage in building mechanical interlocking in our case we have a bicolour led at each lever , red locked , green unlocked , red flashing , lever out of position simple and easier to understand
  14. Modern PC low voltage psus are actually quite complex , as any perusal of their schematics will testify
  15. I don’t know what you’d think of our big O gauge DCC layout with 2x10 A and 2x8A switchers feeding it !!
  16. Other then the consumption of wire there is no other drawback to a low voltage ring main , however twice the number of connectors etc give opportunities for poor installation and hence unexpected resistances if you size your wire right , you don’t get any issues with voltage drop anyways and wire is expensive , ring mains are essentially simply doubling the conductor area ( the ring main has largely been replaced by radials )
  17. At the cost of those levers , using them for dummy operations is a rather expensive peccadillo. as a builder of a 72 lever frame , my view is dont bother with dummy levers unless you have a penchant for absolute fidelity and mechanical interlocking , there are tablets you can take that help this condition include levers to make your layout work as required , a model railway will never be a facsimile of a real railway. if the frame is large , evaluate the operator workload. ( especially if you add bells and what not. )
  18. At £20 a decoder for a basic but high quality brand from Zimo and controller solutions from £150 up , why not buy 1 loco next year and convert the remainder
  19. Obviously not on a mac with iCloud then , you poor thing , not only are my bookmarks backed up , they automatically transfer across all my devices ( 7)
  20. When I designed the big O gauge now at 20 baseboards , it was always intended to be an exhibition layout. I was determined to ensure that past mistakes weren’t repeated and that the goal of a complex but reliable layout could be conceived. This extended to running reliability etc. Yes this needs a bigger budget and a careful and controlled process with one person in charge of that process , even if many people contribute to the work The result is a layout that can be erected and basically operational within 1 hour. And to date the record for dismantling and
  21. We have a very electrically complex layout , using MERG Cbus , etc , one disconnected wire in 6 exhibitions , its not the complexity that causes unreliability , it’s the poor standard of typical electrical installs that causes the issues
  22. Don’t use mains twin and earth , it’s like wrestling with a snake buy a few metres of decent stranded cable
  23. They are not acceptable terminations for 230-240VAC systems , US wiring code is about at 1950 compared to European standards , they are not specifically banned but difficult to make compatible with most European safety codes they can of course be used on low voltage systems
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