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97403_Ixion

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  1. Have the DRS Mk2f's come in now as they say they're bringing some along to the event? I have got a set on order already, so expecting the postman soon, if so... (and the 20's!). Wish I could go to the event but sadly not this time. Hope it's a good day for all that do!
  2. I only have some of the older Farish coaches but these will help model the later scene. I have always been interested in the Pullmans, so a good call! Something to go behind Tornado? Will almost certainly get a rake... or two... Well done Revolution Trains (again in one day!).
  3. I remember seeing an underground train at Oxford Model Railway Exhibition back in the 1970's! I felt it was probably N-gauge as despite me being small, it looked small to me and I could see it from the side wall of the layout I always wanted to see an N-gauge one, so this is a real positive surprise! Well done Revolution Trains! I especially like the IOW interest in them... definitely one to order
  4. I have just checked mine (S2101-01) and there are two pieces of paper with it - both regarding the model itself (DCC, parts, etc.). I don't see a separate note as such (receipt or on the box), though I do put in good faith that a donation was made... checking back it looks like ~£8? from a Newsletter. As far as the model itself, I'm generally a diesel person but was happy to support the venture and very glad I did. The thing that stood out to me was the fine level of detail. I don't have many steam locos but the work put into this comparatively small engine was very pleasing to see. I'll be keeping eyes open on this company (I already have a number of the great little VEA vans). So, well done to the team, especially Sam, on this first loco in N from Sonic Models.
  5. Hi Ben - pricing error on 59206 (Freightliner Orange / analogue version)? I think there must be a price typo on the 59206 'John F Yeoman' DC/DCC Ready version on the Revolution Website - showing the same as the sound fitted version: Freightliner Orange - 59 I'm so glad you announced the 59 as it's one of my favourite locos. When the other manufacturer's model in N was temporarily suspended (understandably, I might say), I felt disappointed. However, I was really hoping for 59001 in FY Silver... so I am sure a decent order will be coming you way very soon. My only other hope is for 59002 'Alan J Day' in the special livery Thanks, Ixion.
  6. So many options, details and a couple of new ideas... well done Bachmann! With other manufacturers showing what they can do, it's good to see Bachmann attacking this loco class with similar levels of detail. Look forward to hearing the new announcements Additional...I wonder if the BCC will do a special version of this loco as its next/future release? I was only thinking about it the other day, believing it never would happen with the current tooling but with the new tooling, maybe the option has been provided for...
  7. I'm no ace at building models but I'd be pleased if I had done so well as you! You've obviously had one for some time... now I can't wait for my 'easy-route to having one' one
  8. @96701 I too am looking forward to receiving mine and most of all I am sure, like you, will enjoy owning one and most likely running it. I've never seen the real thing but all experimental locos fascinate me either through their engineering or just their general uniqueness. Buying models gives me the chance to experience what it must have been like to see various locos long since gone, either in action or to admire their general presence or perhaps tell a story of development through the ages. Although I fear how many experimental locos are becoming or even could become RTR reality, I welcome manufacturers to offer them so I can continue my enthusiasm for and enjoyment of them. But hats off to KR Models for attempting some of the most unusual ones though!
  9. In essence, the brightness is down to the current magnitude - basically, the number of electrons dropping the energy level per second As the diode changes little in forward voltage for fairly significant changes in current, a potentiometer will do the trick to a first order... though using a log pot may make it a bit sensitive at the one end. Also worth putting a fixed resistor in there too so when the pot reaches near to 0 ohms, it limits the current to the maximum brightness of the LED. I tried getting some photos of the Kytes models but they are not quite what I was after - if I can, I'll try to get some better ones tomorrow. The models are quite expensive but then they are quality models with a lot of manual work behind them. They often supply a small 2 x AAA battery box to power the model but also do a proper regulator if running off 12V or another voltage. I remember them telling me not to use rechargeable batteries in the AAA box though as they had heard of cases of the LED's blowing when the batteries were found to be running above 1.5V...not heard of that myself but I bow to their experience! They often put warnings on the boxes saying '3 Volts DC Only' so using one of their regulators should protect over a wide range of voltages. As I say, they are good models with very bright flashing blue lights. Just checked the AA van - the two yellow lights on the rear flash in quick succession then off for a brief period before repeating. I might have to create a 'On The Workbench' like thread... I don't post too much myself but more than happy to share comments, ideas and maybe one day details of a layout!!! Will look into that and let you know... Cheers, Ixion.
  10. Just found this video online of an ambulance and a fire engine - Emergency Vehicles - Kytes Lights. Judging by the track this is OO gauge but they do N gauge ones too. I vaguely recall that they couldn't fit one or the other light, maybe the headlights, but they are pretty impressive things. If I can, I'll try to get an N gauge one out over the weekend and see if I can get a photo. PWM control will allow you to technically do any kind of light animation but the potentiometer way is easiest to start with. Glad the 31 is still running... hope the emergency response vehicles won't need calling out Have a good weekend, Ixion.
  11. Hi Nick, Glad it is sorted for now! Keep an eye on whether the diode gets hot in anyway, which could indicate a partial short or similar. It may just be an under-rated diode (voltage-wise) in the design, so if it does fail again, I would have thought the 40V (reverse-bias) ones suggested should be suitable. I like that buffer-stop LED! The trouble with LED's these days is they are so bright, so putting a larger resistor inline should help quite easily. Alternatively, pulsing it rapidly with variable on-off times can yield the same effect but a lot more electronics is involved! The Network Rail transit van in my picture was not the Kytes Lights one but I do have a very similar sized one by them in yellow with the AA (Automobile Association) branding on it. It has yellow lights if I remember right but the real impressive ones are their fire engines and ambulances which have very well sequenced, high brightness flashed blue LED's, along with other lights where appropriate. How they get the wires in is a masterpiece of work without them showing but they are great in cameo scenes on a layout... the only downside is no sound (though it may be possible to modify the OO ones to fit it?!). Always glad to help people out... it's what forums like this do well... but I do appreciate your thanks Keep enjoying your modelling! Thanks, Ixion.
  12. Those 33's are good, aren't they?! I like the layout - looking good! Ironically, I was adjusting a PCB symbol for a diode after a big design review today - funny how life is! You are right about the 500 likely being mV for a regular silicon diode (I could probably go into the maths but I would sound a bit... Sheldon like [Big Bang Theory TV programme]) If the Gaugemaster gives 12V, it's not very likely to be the culprit as you say... that sounds quite a good unit to me - will have to look them up. There is a remote possibility of damage due to Electro-Static Discharge (ESD), which could be down to poor static control... though most models are pretty robust - at least the DC ones! The grass in the photo does look rather good and I would guess it was applied using a static process? I'm not saying the grass would be a problem itself but I take it the models weren't out near the applicator when the unit was used? Since you have two failed PCB's, this probably rules this out... unless both got near the static at different times... clutching at straws already... Hmm, it's a puzzler! I've done a quick check of what I suspect may be a suitable diode. It's a schottky, rated at 40V, 500mA, so I would suspect it is more than capable of a few LED's... for which I am thinking the motor does not form part of the circuit beyond the diode bridge rectifier. The part is: PMEG4005AEA - link to RS Components (other suppliers also available!). It looks to be in a SOD-323 package (~1.7mm x 1.25mm), with small leads at either end. The pack size is 20 @ ~26p each, so plenty spare and not too expensive to try... Another possibility, would be to use a sacrificial diode from the spare PCB... at least this may get a quicker response. Though be careful to fit it the right way around, or it could blow it... Now, I'm not saying it will solve the fault that causes the problem but if it is inherent in an under-rated diode, then it could. It may also give you a chance to get the model up and running. There may be a fault or short elsewhere on the PCB, so don't despair if it fails again... If you can run the model with the bodyshell off, carefully touch the diode while running the 31 up and down a few times - if it gets hot, there is likely a short elsewhere which may need sorting too. If it runs cool (or luke warm) then it's probably OK. Now... my turn for a photo... These N gauge motor vehicle models by Oxford are great! I was blown away though when I saw one with lights fitted by Kytes Lights - so much so I had to buy it! I'll keep thinking of other possible causes for your model and let you know... I think I have a 31 in my collection but will need to track it down - I think it went into store in a large cardboard engine shed with other locos ...and no problem helping out - I'm not so good at getting my own layout up and running but I do like seeing other people's layouts at exhibitions and on here, so helping others out is always good. Cheers, Ixion.
  13. Hi Nick, I've had a really long day with CAD problems on work stuff, so can't provide a good analysis today but regarding the 169, did it say 169 with the suffix 'mV' on the diode test? Diode tests are in volts (or millivolts), not ohms, so the reading of 169 may look a bit odd if misinterpreted. If so, this could well be right for a working diode (i.e. your D4 from your spare PCB) and suggests it is what they call a Schottky diode, which has a lower forward voltage than regular silicon diodes. This type is likely to be used to prevent voltage drop in a rectifier circuit which basically turns AC (such as a DCC powered rail) into DC... and with four diodes side-by-side, it looks like it could be what they call a full-wave rectifier. In DC mode (which I think is what you are using), the diodes work in the same manner but only one half of them conduct when running in one direction; the other pair in the opposite direction. I found another PCB photo online and it looks like the two feeds from the DCC connector's middle contacts are the Rail power and feed into this diode arrangement. This would be to create a DC supply of some sort - probably for the LED's/lights. Now, if diode D3 or even D1 were to fail short circuit (or low value), it would mean the track would be trying to drive the supply across the other, non-failed diode directly which would limit the voltage across the track... this tallies with you not getting movement in one direction as it effectively short circuits the motor's supply of power. In the other direction, the diode effectively conducts due to its shorting fault but as such, is acting like a more perfect diode - hence the track would not be short circuited and the motor would run. Hopefully that makes some sense?! I'm wondering if the switches control the rear lights? i.e. so light loco (front and rear lights) or train setting (front lights only) can be set - perhaps one switch for each end? So, the rear lights may not show when the model moves if the switch for that direction is in the wrong position. However, you would get no lights at all in one direction if the diode in the rectifier circuit has fused short circuit - but this only applies in one direction. All your comments do seem to suggest this. So.... the question is why did it fail? I hate to say it but production costs may be a cause - i.e. cheapest possible that does the job - not saying this is it but it could be a factor. A diode can fail through a few means - mainly over-current and over-voltage. It is probably unlikely that over-current is the cause, as the rectifier probably only supplies the LED's, which generally draw low amounts of current, though capacitors may exist which need charging rapidly and could cause a failure. However, another failure mode is over-voltage where the diode junction just cannot cope in reverse bias, so fails (breaks down in a non-recoverable way) and allows a current flow in either direction. This is a possibility! What kind of controller are you using? I have a Digitrax DCC controller and it has specific settings for N, OO and O gauge... though I would imagine DC controllers are not specifically rated for N or OO but more generic (I only have H&M or Bachmann's trainset controllers otherwise!). It is possible the diode ratings are a little near the mark and the controller is just a bit over the mark. Another possibility is a short has formed somewhere else - loose wire perhaps? As I say, it may take a little bit more thought to resolve your issue but what would be useful is to know the size of the diode - length and width. This will help identify the package type, though it looks like it may be what is called an 0805 (80 thou / 2mm by 50 thou / 1.25mm). This should help identify a diode that would be suitable. Rated to enough current and voltage with some margin should ensure it works properly for years to come! I must get some rest now (as I say, a long day but helping out is always a good thing!). I'll see if I can find anything more out in the meantime... but I suspect a badly rated type of diode or an over-voltage controller may be the cause. Cheers for now, Ixion.
  14. Hi Nick / EMP, Firstly, welcome to the group! This is a good place to get advice from others as no doubt, someone will have had a similar issue at some point. A very useful place. I am not aware of the details of the PCB inside the 31 but I am an electronics engineer by profession, so may be able to advise... Did the loco once work but has now failed, taking out the PCB and also the spare PCB? i.e. did the fault occur after some previous use? I ask because zero ohms for a diode is not my normal experience of a failed diode. It sounds like there may be a short circuit somewhere else beyond the PCB. It's not likely, though not impossible, that both PCB's could have been faulty from the start... small components can become shorted between the pads underneath during the soldering process. However, I suspect this is not the case, or luck has not been favourable! I imagine to fit the spare PCB, you must have connected wires to the PCB somehow - are they all plug/socket connections? It sounds like you haven't soldered anything yet... If this is the case, can you remove the PCB, then re-check the diode resistance? Measure it in both direction too - there will often be a difference - it may even read open circuit one way around. If, having removed all the wires to the loco, the diode does not measure short circuit anymore, then clearly, there may be something in the loco itself. What may also be of help to me/us is a photo of the PCB... it may be possible to see the context of the diode with regards to other components on the PCB and/or connections to the loco. It may take a little time to work things out but I am sure it probably will be solvable. A new diode may be required, though there are a number of different types (power, current, forward voltage, etc.) but it most likely will not be necessary to source the exact same type - there are a myriad of manufacturers, all competing to sell their own! However, if the diode has failed, it's best to try to understand why, first. Let us know how you get on with the PCB isolated and if you can supply photos, that may help the diagnosis. Cheers, Ixion.
  15. Could well be why! As much as I like certificates with numbers or knowing the production size for specials, given the circumstances for these models, the priority must be the charities the sales help. I cannot thank the NHS enough for what they have done for everyone over the year and continue to do so, so this did seem like a great way to help boost the funds for the charities and a route by which we all could help support them.
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