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Post by boxcarwilly on Sept 24, 2017 12:05:39 GMT -5
I am about to undertake a massive lighting project on the new expansion of my layout and I am seeking some advice as to how to go about it. I have added lights to other sections of my layout with success, but frankly it was very tedious and I'm looking for a much easier and efficient way to accomplish this task. In the past I have used fiber optic cables from a central light source and been disappointed in the results. I have used lights that I have acquired from sources in China which all require resistors to be soldered to one wire and then tying them altogether into a central connection and power source. I have managed to make this latter system work, but the fine wires make it so difficult to see let alone work with. I have a total of 35 lights to add to this new section, two of which will be installed in a building. I am looking for the simplest way to connect the lot without a great deal of must and fuss. Ideally, I would like not to have to deal with resistors on all 35 lights, but I don't know how to do that. I have looked at the lighting system from Woodland Scenics and while I agree it is infinitely easier and efficient to use, they do not make street lights for Z scale nor do they have any plans, now or in the future to do so. The smallest they make is N which is too big for Z scale. I have also looked at the system from Rohukan but it is far too bulky a system to use generally speaking, and again they do not make street lights for Z scale. Additionally, I'm not sure that their system can be expanded far enough for all 35 lights to be controlled from one source. Which brings me to these questions.
1. Since I have to use lights from China which require resistors to be soldered to one wire, is there a quick and easy way to connected them all together?
2. Does anyone know of ready made street lights for Z scale that I could use in place of these lights from China?
3. Does anyone know of a three way connector that allows the main power wire to pass through while a third wire comes in from the side to connect the light which forms a T?
4. Is there such a thing as a quick connect device that takes wires that are not much thicker than a human hair? I have scoured Google and have not been able to find such a device?
5. If using these lights, do I need to use a resistor for each light, or can I use a resistor soldered to the positive wire coming from the power source?
Any helpful hints would be greatly appreciated.
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Post by markm on Sept 24, 2017 12:42:24 GMT -5
Well first off what is the lighting element you are using? LED? Grain-of-wheat bulb? Something else? Some of the answers depend on the light source. At this point some partial answers:
1. There are probably ways to reduce your resistor count and not have to wire them all to one place. Depends on the answer above.
2. Märklin makes street lights as well as Brawa, but at $20 each they aren't cheap. Also Märklin has a bulky electronics board that needs to go until the benchwork.
Mark
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Post by Deleted on Sept 24, 2017 12:53:48 GMT -5
5. If using these lights, do I need to use a resistor for each light, or can I use a resistor soldered to the positive wire coming from the power source? I think that what You are calling "lights" are really Led devices . It is not possible to connect Leds in parallel with only one resistor. If it could help You : link. |
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Post by rvn2001 on Sept 25, 2017 5:51:03 GMT -5
I just use a 3 volt power supply and don't need resistors for LED lights.
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Post by neverland on Sept 25, 2017 10:17:01 GMT -5
I just use a 3 volt power supply and don't need resistors for LED lights. As do I. Too much voltage, especially structure lighting, & the walls & roof glow! |
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Post by boxcarwilly on Sept 25, 2017 10:24:21 GMT -5
I should have mentioned that in the beginning of my thread, yes they are LEDs. I looked at Marklin and Brawa, but aside from the expense, I don't like the little circuit board that goes with each light. I have one of those now on my layout, and it was a real pain to install. In the end, it doesn't work all that great. I was hoping to find some kind of three way connector but so far have come up empty. I'm intend on using the accessory terminals on a MRC transformer which will be dedicated to just powering lights regardless of where they are.
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Post by boxcarwilly on Sept 25, 2017 11:39:00 GMT -5
[/quote]I think that what You are calling "lights" are really Led devices . It is not possible to connect Leds in parallel with only one resistor.
So if I understand what you're saying, I have to use a resistor for each LED and not for the main power wire coming from the source. If this is true, it's what I did for my other lighting using LED's. Doing it this way, just makes the job that much more tedious.
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Post by BAZman on Sept 25, 2017 12:04:25 GMT -5
Most of the China LED's I've purchased already had resistors (rated for 12 volts so *they have to include* resistors. While white LED's are "3 volt", it's not anywhere near exact. LED's also have the 'negative resistance' effect so the warmer the LED gets, the lower the voltage needed to light it. This means, without a resistor, they can 'runaway'and potentially burn up. Paralleling LED's makes it worse. As one gets warmer, it begins to draw more of the current so the others become cooler and the same above scenario gets the probability multiplied, 'runaway'and potentially burn up. While 10 milliamps (.010 amps) is nominal for an LED, the white ones have become ever so bright and many have more than enough brightness for our use. So, resistors come in 5%-10% increments but just using common values, a 1K (1,000 ohm) resistor is more than bright enough, a 10 k (10,000 ohm) will be ~10x dimmer, might be just right. 1 resistor per LED. If you wired all LED's in parallel, and expect to use one resistor, it is still not a good idea. And while an 1/8 watt resistor will run that 1 LED, paralleling 10 LEDs and using 1 resistor now means 10X more current. Power (watts)= I^2 * R. So at 10 milliamp (.01 A) per LED, that is .001 A x 1000 ohm = 1 Watt (A 1 Watt resistor is larger than a #2 pencil end). Just be cautious. You can purchase x number or resitors in a single package. They are called 'SIP' for Single Inline Package. Here is a link to several sources: goo.gl/PZMkro |
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Post by markm on Sept 25, 2017 14:40:35 GMT -5
Jeff has done a good job covering the issues of not using resistors so I don't see a need to continue. To minimize the number of resistors, I would suggest running the LEDs in series with a resistor. Yeah, it's like those old Christmas tree lights if one burns out, but LEDs last MUCH longer. I'm thinking of 3 LEDs in series with a 270 to 470 ohm resistor at the end. This reduces your resistor count by about 2/3. I don't recommend using 4 LEDs and omitting the resistor for reasoning similar to Jeff's post.
I really don't know of any reasonably priced crimp type connectors for fine (34AWG) wire. An alternative to soldering wire this thin is wire wrap. But that is new equipment and techniques you probably don't want to get into.
Beyond that I would suggest something like the RadioShack 276-150 PC board (I believe they are still available through their website). You can solder the resistors and wires to the board and the board is (was) cheap enough that you can scatter them through the layout.
Hope this helps,
Mark
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Post by ztrack on Sept 25, 2017 16:21:15 GMT -5
You may want to reach out to John Cubbin at ztrains.com. He is preparing to release a line of plug and play lighting for Z scale. You can email him at:
john@raildig.com
Rob
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Post by boxcarwilly on Sept 25, 2017 17:59:23 GMT -5
Jeff:
Thanks for your explanation but the truth is, I really didn't understand a word you wrote. Frankly, I do not have the technical knowledge to comprehend what all your figures mean. But correct me if I'm wrong, are you saying that I can only run 2 or 3 LEDs from one power feed, even with resistors attached to each, before I run into the dimming affect? All these LED's come with resistors included and are specially selected to step power down from a 12V transformer. By how much, I have no idea. I do seem to recall, however, that all these LED's draw 3V or less.
Let me see if I can paint you a picture:
Take two wires, red/black, red being positive and black negative. Run them from the accessory terminal of the power pack. At some point between the pack and the first LED, install a resistor on the positive wire. Now assuming there was some kind of 3 way connector, the positive wire would connect to both sides forming the through part of a T. Now we take the LED and connect the positive side W/O a resistor to the side of the connector which forms the bottom half of the T. Each LED is connected to the positive wire in the same manner. The negative feed from the power pack is done the same way BUT without a resistor.
If I understand what Jeff and mark are saying, this would work for 2 or even 3 LED's and maintain the same brightness level, but beyond that, there would be a drop in power and all remaining LED's would be dimmer?
However, if I do the same thing as above with the main feed wires, but eliminate the resistor from the positive wire between the pack and the first connector, and instead have the resistor on the positive side of the LED which then joins the connector, and continue this process for all 35 LED's, the power would be constant on the through positive, but reduced to each LED as if there were only one LED being powered, therefore, each LED would have the same level of brightness?
One more thing: Can I shorten the wires on the resistor itself without causing any damage or power loss?
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Post by markm on Sept 25, 2017 19:17:22 GMT -5
Willy, First off the resistor leads as well as the LED leads can be any length you need. No problems. It seems that fundamentally you understand the issues, but let's do a picture to make everything crystal clear.  For a white LED, typically the Vdiode will range from 3.0-3.6V and the Idiode will be specified at 10mA. If the supplier just specifies a resistor value and no Idiode, we can calculate that. (1) is how the supplier wants you to wire the LEDs: one diode, one resistor. (2) is a series connection. Each diode will be the same intensity, but if one fails, they all go out. You can use as many diodes as possible while still staying at a total voltage less than the input. I used the number three because more would excess the input voltage. If you wanted to increase the number of LEDs you could use an 18 or 24 VDC power supply. The value of the resistor will be different than in (1). This circuit can be repeated as many times as needed and connect across the throttle. (3) is the parallel connection. You can connect as many diodes as you want as long as the resistor is rated for the power. You don't have control over the current going through the individual diodes so intensity can vary and an individual LED can suck up enough power to overheat, all as Jeff described. Hope this clears things up, Mark |
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Post by boxcarwilly on Sept 26, 2017 9:51:49 GMT -5
Mark:
First, let me say thank you for your diagram and explanation.
Second, even with the this diagram which you have taken so much time to do, it does not really explain to me how I'm going to accomplish what I want to do. Obviously, you know more about this stuff then I do, so after examining yours and Jeff's figures and diagram, I've decided to abandon the entire project. Clearly this is beyond my level of expertise. If we were talking 2 or 3 lights being hooked into the same circuit like in other parts of my layout, then I could manage it, but to try to do as many as I had planned, is just too much. I guess I should have paid much more attention to my dad years ago when he tried to show me the basics of electricity and why things work the way they do. I'll proceed with installing the lights, but with the exception of those in the structure, all the rest will not function.
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Post by boxcarwilly on Oct 11, 2017 10:37:09 GMT -5
After several lengthy discussions with John, who is manufacturing his own lights to be compatible with Rokuhan light hubs, (Thanks Rob at Z Track), I've decided not to give up on my lighting project. I'm encouraged by what John has to offer and about all his advice. Since I can't use my Chinese lights with this system, I don't know what to do with them. I've also made enquiries into the Woodland Scenics Just Plug system and again, my existing lights will not work. So I'm going to have to purchase lights that are designed specifically for these systems. I've been researching both and the Rokuhan system appears to be a lot more economical. The one thing that bothers me about it is, while both offer lights for structures, Rokuhan does not offer lights for things light streets, and station platforms and the like. Woodland offers street lights but only in N scale. They produce nothing for Z, but their structure lights could still be used in this case. It sort of leaves a huge gap in what one can do, so I'm hoping that John's lights will fill that gap. Again, thanks Rob for steering me in that direction. I'm eager to see what he has available when he releases them.
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Post by boxcarwilly on Nov 8, 2017 12:39:17 GMT -5
After much testing and so on, I finally have my lighting project complete and it works believe it or not. I waited and waited for John to come out with his lights, but I decided that I couldn't wait any longer. After much consultation on what would work and what wouldn't, I decided to throw caution to the wind and try using my Chinese lights. I bought some Woodland Scenics light hubs and expansion hub and started hooking my lights into these devices and low and behold, they worked. The beauty of it is, NO RESISTORS anywhere. I did, however, have to solder some thicker wires on those of the Chinese lights because their wires are not much thicker then a human hair and could not be secured in the link connectors. Oh BTW, I had to buy a bunch of linker connectors and some cable plugs off a fellow on Ebay to fit in the Woodland Scenics light hubs and after a lot of fiddling around, I got all the lights up and running. So I'm happy about this. It means I can go on using the cheaper lights from China, and don't have to worry about resistors. Don't ask me why they work without the resistor on each light, they just do and I'll take it. I was going to post a picture or two of the completed project including the station, but I can't so it for some reason. Oh well.
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