Ian-1301567 Posted July 2 Share Posted July 2 Hi all on the Forum, Now I have recently been having a go at fitting LED Lighting Strips in some of my Pullman coaches but some light up and others don't. So I bought 2 9v Duracell batteries and connected them both in series to test to see if the spring pick ups are doing there job as when I touch the 2 copper strips they light up bur when I connect to the wheels nothing happens on some carriages so I assume the problem being the connection with the spring pickup on the axle of the metal wheels. As anybody any ideas as to solving this bit of a problem. Link to comment Share on other sites More sharing options...
What About The Bee Posted July 3 Share Posted July 3 (edited) Hello Ian We've not spoken before, so welcome aboard! You are describing a continuity problem. That is, there is no path from the track to the LED strip. Somewhere, there is an open. 9v batteries are fine for go/no go solutions. What you really want or need is a digital multimeter. For your purposes, nearly any one will do. Set the multimeter to measure resistance (Ω) and test part by part, to find the open. Place one probe on the metal tire of the wheel, say, and the other on the axle. The meter will likely read 0 ohms, meaning its closed or shorted. That's good in our situation. Alternatively, it could read infinite ohms, meaning no continuity or open. Viola! You have found the offender. Using the multimeter carefully, component by component, and you will find the exact faulty connection. Should not take terribly long either. Even with learning your new multimeter, it should be under 1 hour. Once you know which component, it should not be hard to spot the issue. The battery just says its working, not working. But which part? Get a multimeter. Bee Edited July 3 by What About The Bee Spelling Link to comment Share on other sites More sharing options...
Going Spare Posted July 3 Share Posted July 3 As your coaches did not come with factory-fitted lighting, you presumably have the 'Railroad' versions. In which case, have you checked that they are equipped with conductive wheelsets - i.e. one wheel live to the axle - as Hornby's standard rolling stock wheelsets have both wheels insulated. 2 Link to comment Share on other sites More sharing options...
Irishmail Posted July 3 Share Posted July 3 Also of note, if they are Railroad versions, some have plastic wheel sets fitted with will need to be replaced with metal ones. Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 Yeah, I will have to try the multi-meter which seems the best option. As some coaches actually work and light up when placed on the rails about 7 coaches out of 18 actually work so it must be something to do with the either the wheels or the spring pick-up. I'm using 2 of Hornby's 14mm Metal Wheels at the left bogie. Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 By the way I forgot to mention that these are strip lights that i bought from ebay so it was DIY Kit but some coaches are working on the live rails so i must be doing something right. Link to comment Share on other sites More sharing options...
Going Spare Posted July 4 Share Posted July 4 Hornby's retail packs of 14mm disc wheelsets - R8218, R8234 and R8264 - contain fully-insulated wheelsets (neither wheel is live to the axle). As far as I can recall, only spares packs X6950 and X9096 as used on the factory-lit Mk1 coaches and Pullman cars, respectively, contain wheelsets with one wheel on each live to the axle, the intention being that both wheelsets in one bogie would pick up current from one rail while both wheelsets in the other bogie would return current to the opposite rail. If the pick-ups you are using are in contact with only one axle each, pick up and return should be successful from just one bogie if the X6950/X9096 non-insulated wheel on one wheelset is on the opposite side to its counterpart on the second wheelset. Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 That's interesting so you are saying that the metal wheel sets from hornby are useless for use with lighting circuits for the coaches. As some of the coaches i fitted do light-up when placed on the line and they are the hornby 14mm metal wheels. So if they are fully-insulated how do you get these wheels so you can make a circuit with the rail. Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 4 Share Posted July 4 (edited) First thing to do is check the continuity of your metal wheelsets with a multimeter and verify there is continuity from one wheel (only) to the metal axle. There's usually some sort of insulating bush between one wheel and the axle, so if both wheels have that insulation then the axle isn't going to be live at all and an axle or bearing pickup mechanism isn't going to work. Some folk find ways of creating a wire link from the axle to one wheel to get round that situation. Edited July 4 by ntpntpntp Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 Right so if i connect a multi-meter to one wheel and the axle and get a 0 reading does that mean there is no circuit and so won't light the lights up. And if i get a reading on the multi-meter does that mean i have a circuit and the lights will come on when applied to the track. Link to comment Share on other sites More sharing options...
What About The Bee Posted July 4 Share Posted July 4 Ian You need a complete circuit. Power must come from one rail, flow through all the components including the LEDs and down to the other rail. When testing for continuity, you are measuring resistance. Ohms of resistance. If you measure 0 ohms, that means no resistance or a good connection. If there is a large resistance, electricity will not flow, that would be bad. Check. Wheel to axle. Axle to internal LED connections. Etc Step by step Bee Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 4 Share Posted July 4 (edited) @Ian-1301567 only if your multi meter is set to resistance or continuity mode 🙂 check both wheels 🙂 Assuming you have a live wheel and axle you still need to ensure you fit the wheels with the correct orientation to create a power path up one wheel, through the lights and back out through the other wheel 🙂 [edit] Bee wrote much the same thing as I was typing 🙂 [/edit] Edited July 4 by ntpntpntp 1 Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 4 Share Posted July 4 (edited) Relying on just one wheel per side of the circuit wouldn't be my choice, not particularly reliable pickup and will be affected by dead frogs etc. . Most of my old N gauge coaches with lights use both wheels of one bogie for one side, and both wheels of the other bogie for the return. My more modern coaches with lights have stub/half axles and wheels and the axle bearings are live, that way all the wheels contribute to the pickup. Something else which occurred to me: Are you running on DCC or DC? Either way your lighting strips need a bridge rectifier in the circuit so that they will work with either polarity. If you're running DC and don't have the rectifier LED lights will only light up in one direction of travel. Edited July 4 by ntpntpntp Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 So let me get this right one wheel needs to be live and the other wheel is the return to ensure a power path to the LED's and back out through the other wheel. But they are both insulated to the axle then they won't work. So 0 ohms is good and high resistance bad. Have i got this correct?. Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 4 Share Posted July 4 (edited) @Ian-1301567 one live wheel of one wheelset, up through the LED strip etc. and back out through one wheel *of a different wheelset* (usually on the other bogie to spread the live "wheelbase". If you can use both wheels of one side of one bogie and both wheels of one side of the other bogie that's better (more live wheels to pick up and return power). Edited July 4 by ntpntpntp 1 Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 I never realised that the metal wheels where insulated i thought that i hadn't tightened the brass spring up enough around the axle so it was slipping and not making contact.I'm presently running with DCC. I'm sure I've tested the axle with the batteries many times and they have lightened up each time so it's definitely to do with wheels connecting to the track from the axle. Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 I've managed somehow to get 7 coaches to light up but another 12 coaches won't light up. It's a very frustrating hobby. I just need a quick fix to the problem. Link to comment Share on other sites More sharing options...
Rog RJ Posted July 4 Share Posted July 4 Are you aware that many, if not all, these led strips are polarity conscious and if you connect them in reverse they will not light Link to comment Share on other sites More sharing options...
What About The Bee Posted July 4 Share Posted July 4 Hello Ian Slow down! Suppose two metal wheels with a metal axle was in place. That would be a dead short. Like putting a wire from one rail to the other. Consequently, one wheel must be insulated from the rail, and one must not. In this way, power comes from rail A, through the wheel and to the axle. That is where your spring is. After coming down from the led strip, it goes to ANOTHER axle. From there to the wheel and down to rail B. It will not do to have power come up from rail A and down to rail A. Power must flow from A to B. So of the two axles, the live wheel must be on opposite sides. You can do this sir. Slow down. Think about what is happening and you will see it. Bee 1 Link to comment Share on other sites More sharing options...
ntpntpntp Posted July 4 Share Posted July 4 (edited) Here's a typical way of powering carriage lighting. As I mentioned before, the bridge rectifier allows the LED strip to "see" DC with the correct polarity, regardless of DC or DCC or which way the coach is oriented on the track and which way it is travelling. Each bogie is providing 2 live wheels for better pickup. Left hand bogie is picking up from the nearest rail (no insulation on the wheels), the right hand bogie is live to the other rail. Edited July 4 by ntpntpntp Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 35 minutes ago, Rog RJ said: Are you aware that many, if not all, these led strips are polarity conscious and if you connect them in reverse they will not light Well i have tested the lights with connecting batteries to the 2 copper strips and they light up its just the wheels that seem to be the problem. Link to comment Share on other sites More sharing options...
What About The Bee Posted July 4 Share Posted July 4 (edited) Bridge rectifier is likely a part of the LED strip Ian. It is entirely possible, given that the live/insulated axle wheel configuration was unknown, that you simply have one axle non-reversed as required. That power flows from A to A, not from A to B. Bee Edited July 4 by What About The Bee Past tense of require Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 Right so I need one metal wheel of one axle which conducts on one side of the track (A) and the second axle making sure the other wheel which conducts on the other side of the track (B). Is that where you are coming from?. 1 Link to comment Share on other sites More sharing options...
What About The Bee Posted July 4 Share Posted July 4 @Ian-1301567Precisely!! Link to comment Share on other sites More sharing options...
Ian-1301567 Posted July 4 Author Share Posted July 4 Great i must have two wheels which are conducting on the same rail and they aren't flowing to make the circuit. Many thanks Bee. 1 Link to comment Share on other sites More sharing options...
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