71H Posted July 24, 2017 Share Posted July 24, 2017 Good afternoon all. First off, I'm hopeless when it comes to electrical things so bear with me please. I have a DCC powercab only, sat waiting for my first ever layout to be built. Now, i purchased the other day some street lights, 00 scale LED ones but I haven't the foggiest idea what to buy to make them work ? They are 3v to 12v street lamps. Switches are one thing I need but what power unit would work them etc, I haven't a clue ? Does anyone know what I need please, or more to the point, what on earth I am on about ? Many thanks all that reply. andy Link to post Share on other sites More sharing options...
amdaley Posted July 24, 2017 Share Posted July 24, 2017 If you have an old phone charger you could use that. They are normally about 5 volts so should work. Just cut the connector off & connect the two wires to the lamp. To switch it on & off insert a switch in one of the wires. Link to post Share on other sites More sharing options...
HLT 0109 Posted July 24, 2017 Share Posted July 24, 2017 Andy, are the lamps already fitted with the necessary resistors? If not, they may blow if connected direct to the power supply - it depends how they have been made. I am scarcely more knowlegeable about this than you are but it might be worth a chat with your supplier. Most LEDs need a direct current supply rather than AC and you may need a bridge rectifier if taking power from your DCC supply. Bear in mind that DCC supply is 16v anyway. Harold. Link to post Share on other sites More sharing options...
MartynJPearson Posted July 24, 2017 Share Posted July 24, 2017 The LEDs will need a DC supply - three important points are (a) don't exceed the voltage specified on the lights, (b) ensure the polarity is correct and © ensure you use the current limiting resistors provided with the lights. As Harold says, taking the supply from the track will need a rectifier to convert the track current to DC (simplistically, DCC is more akin to AC). However, you may be better off getting a plug in adaptor - along the lines of a phone charger or power supply for small electrical devices like routers, modern phones etc. If you have any knocking around, do check the voltage (and, if you are powering a lot more than a few LEDs, the current) of the power supply to ensure it is suitable. If you don't have one, then you can get them from Maplin, eBay etc - for example, this one : http://www.ebay.co.uk/itm/Universal-Mains-AC-DC-Power-Adaptor-Supply-Plug-Charger-3v-4-5v-6v-7-5v-9v-12v-/370897337707?epid=1548409991&hash=item565b343d6b:g:wboAAOSwHMJYL0IT (this is just an example, although it looks from a quick glance that it would suit your needs) A multimeter will help ensure that the polarity is correct - and in general is a very worthwhile investment. You could either wire up a socket that the power adaptor output can be plugged into (the example above comes with a number of connectors so you should be able to find a suitable socket), alternatively, the end could be hacked off and the wires soldered directly to the feed to the lights. Link to post Share on other sites More sharing options...
71H Posted July 24, 2017 Author Share Posted July 24, 2017 Gents, thank you very much for your replies. Yes, the 12 street lights do have resistors on them all. I would like to have the DCC separate from these lamps and so, am I to understand that I will need 12 mobile phone charger's for these lamps or could I wire up all 12 to light them up ? I'm sorry to ask these questions but hopefully someone might say you need to do X Y Z to make them work...... Thank you again gents. andy Link to post Share on other sites More sharing options...
amdaley Posted July 24, 2017 Share Posted July 24, 2017 It depends how many amps the adaptor can output. Each light is unlikely to take very little power to light so you will probably be able to light several with a single adaptor. Look at the label on the adaptor & see what ampage it says ? Link to post Share on other sites More sharing options...
71H Posted July 24, 2017 Author Share Posted July 24, 2017 Thank you for that Tony, I'll look at the ampage tomorrow. I've got two spare mobile charger's in my store room. andy Link to post Share on other sites More sharing options...
MartynJPearson Posted July 25, 2017 Share Posted July 25, 2017 If you allow 20mA for each LED, then it's a case of dividing the rating of the transformer by 20 to see how many LED's you can power. So if you have a 500ma transformer, then that should cope with 25 LEDs. The actual consumption may well be lower (e.g. if you the resistors in series with the LEDs are 1k, at 12v it'll be in the region of 12mA per LED). Link to post Share on other sites More sharing options...
Campaman Posted July 25, 2017 Share Posted July 25, 2017 I have a set of 240 led lights running round my garden powered by 1 AAA rechargeable battery which is re-charged by a small solar panel, so 1 simple DC adapter should run your 12 lamps or more with no problems at all. Link to post Share on other sites More sharing options...
wombatofludham Posted July 25, 2017 Share Posted July 25, 2017 I don't know if this is of any use, I spotted it on eBay and it looks like it might make connecting low voltage LED streetlamps to a transformer a bit easier. Caveat, I've not yet bought one to try but will when I start installing streetlamps on my shed layout. http://www.ebay.co.uk/itm/1-x-self-adapt-power-distributor-OO-N-O-LED-street-light-hub-distribution-board/152322228333?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649 eBay also has quite a few pre-wired battery holders which can be used with LED lamps. Link to post Share on other sites More sharing options...
d00m Posted July 25, 2017 Share Posted July 25, 2017 A very usefull tool... search online for 'LED Calculator' this lets you put in the voltage supply, assume as above 20mamps per led and it will tell you the correct resistors to use. Hope this helps. Ps you can also choose series or parallel - it designs the circuit for you! Dom. Link to post Share on other sites More sharing options...
d00m Posted July 25, 2017 Share Posted July 25, 2017 Sorry forgot to mention led forward voltage without resistor should not be more than 4.5v max for white as a rule (2 to 2.5 max for red ) I would guesstimate 4v for white or warm white. Link to post Share on other sites More sharing options...
71H Posted July 26, 2017 Author Share Posted July 26, 2017 Thank you gents. I've sent an email to gaugemaster and I'm awaiting a reply from them. I have a nasty feeling that I've bitten off more than I can chew when it comes to electrical thing's lol. andy Link to post Share on other sites More sharing options...
Classsix T Posted July 27, 2017 Share Posted July 27, 2017 Is there a model railway club local to you Andy? RMWeb is a great resource for information but you'll benefit greatly from speaking face to face with a demonstration of what you require. Teach a man to fish and all that. C6T. Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted July 28, 2017 RMweb Gold Share Posted July 28, 2017 (edited) You probably haven't bitten off more than you can chew, andy, but need to take smaller mouthfuls. You say you haven't even started building a layout yet, so you have plenty of time to find out how to manage street or other ancillary lighting and learn by trial and error by experimenting with the ones you already have. May I make a plea for you to keep the lighting low key, with due regard to Rule 1 of course; I see many layouts on which the unspoken rule seems to be 'look at all my bright lights, aren't I clever to have bright lights on my model railway, see how bright they are, look, these ones flash, aren't they bright'. They look awful, much too, er, bright. If you can see a pool of light beneath the street or platform lamp under normal ambient 'daylight' lighting conditions, that's too bright, by a factor of a lot. For steam or early diesel layouts they need to be not much more than a dull warm glow, and even in the modern image world of brightness and superclean shiny dazzle, not nearly as bright as they are usually modelled; if they were that bright in reality scaled up we'd all have smoking ruins where our eyes were! This means that you can, to an extent, get away with much less current than you need to light the leds to their full brightness, which will also help with any heat issues. Subtle use of low key lighting in 'daylight ambient' conditions is a very good way of suggesting a dull or rainy day on a model as well; I intend to have some buildings internally lit in this way on Cwmdimbath in order to invoke the correct '1950s South Wales valleys always raining unless it's about to start raining' feel of the place, but it is a low priority when the scenic break isn't even properly started, the fiddle yard needs an extension, and a lot of detail work is not yet done. A proper layout lighting rig has yet to be designed and built, but at least I have a vague idea of how this is to be accomplished... Edited July 28, 2017 by The Johnster Link to post Share on other sites More sharing options...
Pete the Elaner Posted July 28, 2017 Share Posted July 28, 2017 Why not build a simple circuit with 1 LED & go from there? As above, to be realistic, lighting need to be scaled down to quite dim. After you get more comfortable with your simple circuit, you could swap out the resistor for a variable one in order to find the lighting level which looks good, then find out which resistance you have & get fixed resistors of this value. If you can't or don't want to join a club, then ask around at an exhibition. Most layout owners are very willing to discuss how they have built their layout & will usually respond well when you ask them to keep things simple. LEDs are much more efficient than bulbs. Bulbs consume far more power & waster a large amount of it by getting very hot. LEDs do get slightly warm but nowhere near as hot as a bulb. This is why they use less power. Link to post Share on other sites More sharing options...
71H Posted July 29, 2017 Author Share Posted July 29, 2017 Is there a model railway club local to you Andy? RMWeb is a great resource for information but you'll benefit greatly from speaking face to face with a demonstration of what you require. Teach a man to fish and all that. C6T. Thank you for that C6T, I shall make enquiries next weekend at the Exmoor railway exhibition at Minehead. Also, thank you for your information Johnster and Peter. I have purchased a Gaugemaster analogue controller and it has a 12v accessories socket for lights. I shall try just one or two street lights for starters, I don't want something that looks like Blackpool illumination's, just something simple first of all. Baseboards are constructed, track weathering is in progress etc. It will be interesting to see if there is a club somewhere around Exmoor because I will need help with wiring the layout. Gents, thank you all for your kind help and input. andy Link to post Share on other sites More sharing options...
amdaley Posted July 29, 2017 Share Posted July 29, 2017 Thank you for that C6T, I shall make enquiries next weekend at the Exmoor railway exhibition at Minehead. Also, thank you for your information Johnster and Peter. I have purchased a Gaugemaster analogue controller and it has a 12v accessories socket for lights. I shall try just one or two street lights for starters, I don't want something that looks like Blackpool illumination's, just something simple first of all. Baseboards are constructed, track weathering is in progress etc. It will be interesting to see if there is a club somewhere around Exmoor because I will need help with wiring the layout. Gents, thank you all for your kind help and input. andy Don't take that as given Andy. I no longer model in DC but when i did many of these controller accessory sockets put out a lot more than 12volts. Link to post Share on other sites More sharing options...
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