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Keikyu

How do you wire up Kobaru stuff?

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Keikyu

I have searched the forums and gone back a fair few pages here but can't see too much. if I have missed anything, please let me know.

 

Anyway, I have had a Kobaru red lantern led set lying around for a while. Ideally, I'd like to be able to wire it up to a battery pack of some kind so i could have some batteries supplying power to a few Kobaru lanterns and maybe some vending machines and streetlights.

 

My problem is I have absolutely no idea how to make them work. I know absolutely nothing of powering leds and my friend that does know is out of state for a fair while and can't help me do what I need.

 

So is what I would like possible? And could I light them up with little to no experience?

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Lawrence

I had a look at the set you mention on the HS page but it only has a pack image so I have no idea as to how the wiring looks, a picture of the one you have with all the wiring would be helpful.  If the set has built in resistors it should just be a case of connecting it up to a power supply (or batteries) with the usual +ve and -ve

Is there any indication on the pack what supply voltage they recommend, normally if built in resistors are fitted it may suggest 9 - 12 v DC, if it is unprotected it may suggest 3 - 5 v DC

 

You may want to consider something like  http://tinyurl.com/nssep6o available in many colours and can be cut into strips of multiples of 3, these have built in resistors and can run from a 12v DC supply, very useful for building lighting

Edited by Lawrence

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Keikyu

Alright, this is what the leds look like.

 

bHh77FD.png

 

Unfortunately I have no idea where the packaging is that had the voltages on it, though I think the website might have it.

 

And I was looking for something like those leds, what I would like though is a battery pack connected to like 4 or 5 difefrent colored leds. Like green leds to represent exist signs and blue ones to represent tvs or alarms. I'm not entirely sure if I can use those strips in that way, but I was looking at these as well:

 

http://www.1999.co.jp/eng/10167575

 

They have battery packs in the recommended items so maybe they could be easier to get up and running?

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kvp

I think you might be looking for this:

http://www.kobaru.com/support/led.html

 

According to this page, you only have the leds in the package and a series resistor is needed. The led forward voltage seems to be 3V (2.7-3.3) and the maximal current is 20 mA. This is normal for a white led.

 

According to this page:

http://led.linear1.org/led.wiz

 

At 12V, you either need 470 ohms for a single led or 150 ohms if you connect 3 in series.

At 5V, you need 100 ohms for a single led.

 

The best circuit for wiring them up is this:

led_10.gif

(with 470 ohm, 1/2 watt resistors)

Edited by kvp
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Lawrence

Nice one kvp, my google translate did not make much sense of the page.  I am curious why they would think wiring the supply lines in parallel would cause the last one to dim though, I am using 1206 surface mount led's wired in series and parallel with a 1k resistor ganged on the returns without any issues on a 12vDC supply.

 

Here is a thread on another forum where someone has experimented, there are lots of pictures, and lots of good learning points  http://www.ngaugeforum.co.uk/SMFN/index.php?topic=9242.0

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kvp
I am curious why they would think wiring the supply lines in parallel would cause the last one to dim though.

 

They are using cheap white leds and that means a forward voltage between 2.7 and 3.3 volts. If you use a common resistor, then there is a chance that two leds will have different opening voltages. (high quality matched sets from the same production run don't have this problem) This difference will result in uneven current distribution between the leds, so some gets more and some gets less. This could even cause the brightest to fail, then the next brightest... Using separate resistors guarantees separate current limits and better brightness levels. (with small variations caused by the 1% or 5% precision of the resistors) Also each led color and type has different forward voltages and need different resistor values for the same current. Not to mention some leds have different current limits. The calculator I linked can be filled from the datasheet of the leds and gives the best circuit for a given task.

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Lawrence

I use that page for reference too :glasses1:

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Keikyu

Alright, thanks for the help

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cteno4

Keikyu,

 

another trick for leds like this is to use a little trim pot. these are variable resistors. you can dim down the light as much as you want using these. you could do the same thing using higher value resistors, these just let you easily dial the level in you want.

 

http://www.ebay.com/itm/3-x-2K-OHM-Trimpot-Variable-Resistor-6mm-/260807407449?pt=LH_DefaultDomain_0&hash=item3cb9553759

 

a 2K trim pot will dim alot on a standard 3v 20ma led to 3-12v. you do need to measure and mark where on the pot the minimum resistance is you need for your power source voltage (100K for 5v, 470K for 12v, etc) so that you dont have your current too high. or to be safe you can just wire in a resistor for the minimum resistance in series with the trim pot and then the trim pot will just take the resistance higher than the minimum set by your fixed resistor.

 

there are three little feet on these. the single one is your one connection and then the other two will just go high to low clockwise or counterclockwise on the dial. there are a number of forms of these but these little guys are usually the cheapest. in getting more you can get the price down to 5-10 cents each. fixed resistors are only a cent or two each but i like having the ability to dial in the brightness, many times you want only a fraction of the brightness to set it the way you want.

 

i like using 5v power supplies for the leds. less power to have to dump and i dont do things in serial or parallel, just drop the current for each led i use. 5v is really a big standard out there for power supplies.

 

you can solder these up on a little pc board if you have a number of them on a structure to mound under the layout or even within the structure and then just drill some small holes in the base or under the roof line or somewhere so you can pop in a small screwdriver to adjust them. 

 

you can just use a couple of aa batteries and put a very small resistor on each (like 4.7ohm) to just be safe to limit current or put a pot on it as even all the way down there usually is some resistance there. cheap on ebay. will get you many days of led light!

 

http://www.ebay.com/itm/New-2-AA-2A-Battery-Holder-Box-Case-With-Switch-EE4069-/310540389309?pt=LH_DefaultDomain_2&hash=item484da64bbd

 

jeff

 

 

 

 

jeff

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Keikyu

I'm quite confused now, I never was any good with electrical stuff. I do have afriend who is though, I might link him here and see if he can help me out.

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kvp
I'm quite confused now, I never was any good with electrical stuff. I do have afriend who is though, I might link him here and see if he can help me out.

Don't have to. Just get the right resistor for the leds (470 ohm, 1/2 watt resistors for 12V DC or 100 ohm, 1/2 watt for 5V DC) and add one resistor in series to every led. If you find them too bright, then use a larger one (with a larger ohm value) until you think it good. Every other trick is nice but not really needed if you just want them to work and not quite good at designing custom circuits.

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Keikyu

Yeah, all I really want is to light them up with some form of battery pack, so i can switch the lanterns on and off like the Tomytec lights.

 

So I get these resistors, then wire them up like that picture you posted above?

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kvp
Yeah, all I really want is to light them up with some form of battery pack, so i can switch the lanterns on and off like the Tomytec lights.

 

So I get these resistors, then wire them up like that picture you posted above?

Yes! That's pretty much all. The picture is from the manufacturer's website. Just make sure the polarities are correct. (as on the picture) If you don't know which polarity is which, just use a multimeter with a diode tester mode (often used for finding wire breaks) and wire them up with the polarity in which they light up. (wiring them up in reverse or without a resistor burns them out)

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cteno4

Keikyu,

 

if you just want to battery power, really easy. just grab one of the $1 battery 2AA holders on ebay. they have a switch built into them and 3v drives leds fine for many days.

 

http://www.ebay.com/itm/New-2-AA-2A-Battery-Holder-Box-Case-With-Switch-EE4069-/310540389309?pt=LH_DefaultDomain_2&hash=item484da64bbd

 

safest to put in a resistor for each led even from a 3v battery (the lanterns are not cheap!). this can be a very low value one like 10ohm for a white led or like a 47ohm for a red led. just wire the resistor into either one of the LED leads between the LED and the battery pack (does not matter which one). if you hook up the led with the resistor in there you wont blow the led, one way it just wont light up, just reverse the polarity and then it will work.

 

         ____________resistor_________

LED                                                           battery or power supply

         ____________________________

 

if you want the lights dimmer just try a higher value resistor. 1/4 watt are plenty as a single led will only draw 0.06w so even a 1/8 watt would be fine. the rule of thumb is usually to use a 2x the power rating of the resistor to your circuit's needs to be safe.

 

a set of resistors can be had cheap that will give you a nice selection to choose from for projects or to dim down any leds if you want

 

http://www.ebay.com/itm/Total-400-Pcs-1-4W-1-20-Kinds-Each-Value-Metal-Film-Resistor-Assortment-Kit-Set-/390616972617?pt=LH_DefaultDomain_2&hash=item5af295fd49

 

the little variable pots just let you dim things to any degree w/o using a different value resistor, they are just variable resistors!

 

if you want tiny batteries to put inside the building you can use little coin cells. a 2032 battery will get you like 24 hrs on a white led with cheap ebay batteries (longer on nicer quality batteries but the cost per hour will be higher). you dont have to use a resistor with these (they are 3v) as their current output is pretty low, but you can use one to dim some if you want.

 

http://www.ebay.com/itm/gib-10pcs-Portable-CR2032-CR2025-General-Button-Battery-Clip-Holder-Box-Case-/190899382559?pt=US_Single_Use_Batteries&hash=item2c727d691f

 

http://www.ebay.com/itm/KDQ11-ENVIRONMENTAL-PROTECTION-OF-LITHIUM-BATTERY-10X-CR2032-B2032-SCA-1670-/221299328551?pt=US_Single_Use_Batteries&hash=item338677c627

 

you will need to wire in a little switch to these but the whole thing can fit inside a small building

 

http://www.ebay.com/itm/10pcs-8X8mm-Cap-Self-locking-Type-Square-Blue-Button-Switch-Control-New-/200955972890?pt=LH_DefaultDomain_0&hash=item2ec9e8cd1a

 

http://www.ebay.com/itm/5-pcs-Switch-ON-OFF-SK12D07VG3-1P2T-Right-Angle-4-5x8-6mm-3-pin-DIP-Through-Hole-/151062338036?pt=LH_DefaultDomain_2&hash=item232c0459f4

 

cheers

 

jeff

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Keikyu

Alright, neat. it's not as difficult as I was imagining, only issue I'm really going to have now is I don't have anything to solder, which I assume I will need to be doing. But the aforementioned friend does have a soldering thing I could use.

 

Thanks

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cteno4

Keikyu,

 

Its worth getting yourself a cheap soldering iron. a simple one will do you fine to get started. they are very handy to have and you will eventually have to do some soldering in doing model trains!

 

http://www.ebay.com/itm/SOLDERING-IRON-WELDING-TOOL-30W-HEAT-WIRING-SOLDER-30-WATT-with-Holder-Stand-/290715495362?pt=LH_DefaultDomain_0&hash=item43affe6bc2

 

stand is also really great to have if you do much but not necessary, just be careful how you set it down. you can just make a simple one out of some bent wire.

 

http://www.ebay.com/itm/Soldering-Solder-Iron-Metal-Rectangle-Stand-Station-Bakelite-Holder-Base-S9-/310795441213?pt=LH_DefaultDomain_0&hash=item485cda143d

 

get some simple rosin core solder

 

http://www.ebay.com/itm/Tin-Lead-0-8mm-Rosin-Core-Solder-Soldering-Welding-Iron-Wire-Reel-Welding-M2-/141019167804?pt=LH_DefaultDomain_0&hash=item20d565bc3c

 

then just practice soldering a bit on old wire. there are loads of good videos on youtube to show you the basics of soldering wires and its pretty easy. just takes a little practice and you get the hang of it very quickly. its actually very fun and satisfying thing to learn and do.

 

another simple bit is heat shrink tubing. you just put a small length (like 50% longer than your exposed wire joint) of the tubing over your wire before you twist and solder the wires together, then once the solder joint is done slide the bit of tubing over your solder joint and then heat it up with either a hair dryer or just put the side of the soldering iron up close (but dont touch it) and it shrinks up around your wire making a nice clean insulation bit over it. you can get it in various sizes depending on the size of the wires you are joining

 

http://www.ebay.com/itm/100pcs-0-8mm-Diameter-Black-Heat-Shrinkable-Tube-Shrink-Tubing-50mm-length-2-1-/221325828936?pt=LH_DefaultDomain_0&hash=item33880c2348

 

the little magnet wires on the lamps have enamel paint as their insulation. you can easily burn this off by getting a little ball of solder hot on the end of the soldering iron tip and then just putting the end of the wire in it and it will burn off the enamel.

 

actually is very easy and youtube videos are great to help show you how to do it visually.

 

cheers

 

jeff

Edited by cteno4

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Lawrence

Keikyu - I would happily teach you soldering techniques, unfortunately you are probably nowhere near NE Scotland

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cteno4

same here, but you probably are not near wash dc!

 

but youtube videos do a great job of showing you the basics and then its just practicing a bit. watching the sequence and relationship of wire, solder and tip and timing and results really helps. its funny its a technique that many are scared of but its really pretty easy to pick up.

 

I started doing it at 4 years old actually! by the time i was 5 i was wiring up lights, motors, switches and batteries to do really fun things. all my school projects starting in first grade had lights and motors that worked to do various things, always a big hit!

 

jeff

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Keikyu

Alright, I have a basic idea of what I need now. A cheap soldering iron would be nice as I plan on building a new computer with some help soon as this one is dying.

 

You guys know a load about this kind of thing, it's hugely appreciated. I can probably get some basic lighting going to make my small buildings look neat.

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Lawrence
Alright, I have a basic idea of what I need now. A cheap soldering iron would be nice as I plan on building a new computer with some help soon as this one is dying.

 

You guys know a load about this kind of thing, it's hugely appreciated. I can probably get some basic lighting going to make my small buildings look neat.

 

Personally I wouldn't buy a cheap soldering iron as they can leave you frustrated by poor results and will not be good for getting spares etc.  Throughout my career and at home I have always used Weller equipment, yes it is a little more expensive but you do get excellent build quality and can buy a wide variety of tips.  Also not sure you will need an iron for building a pc unless you are planning some radical mods :)

Edited by Lawrence

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cteno4

Well a cheap one will solder basic wire joints fine, wont have a range of tips to do various things or great for fine work, but to just solder a few wires ive never had a cheapo iron i could not easily do simple soldering with. as soon as you get into it though then a nicer iron is really good (and more necessary), especially if soldering small stuff. I have a couple $5 irons that have been around for a couple of decades, great thing to have in the toolbox at shows. dont have the heart to toss them as they still work fine for the basics!

 

really soldering is one of those things in the long run in the hobby you will find useful to know how to do.

 

Yeah not sure what all you would need to solder on a computer unless you want to mod up a lot like Lawrence said. most build your own is pretty plug and play these days. its the time spent trying to get it all configured with os that is the real work there! that can make soldering look simple! if you are soldering stuff on a computer pc board then a better soldering iron will be needed with finer tips. lots of the time you are also unsodering stuff as well so thats another little trick to learn an a couple tools needed like a sucker and a wick.

 

Keikyu are you in the us? if so pm me and i can mail you a couple of little examples and parts of simple lighting setups for you to play with and build from.

 

jeff

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Martijn Meerts

It's better to spend a little extra and get a good soldering iron, preferably a soldering station with variable temperature. If you go for the cheap ones, you will get annoyed sooner rather than later because stuff just doesn't work well.

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Lawrence

Not wishing to hijack the thread but if you have any interesting circuit diagrams Jeff, I would always be interested too :)

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cteno4

sorry I have to disagree, but you can do simple soldering of wires together with the cheapest of soldering irons, ive done it for decades on many many different ones. if thats all you are going to do you really dont need to spend a lot on an iron. Keikyu sounded like he was just going to solder a few wires and was not into spending much money. so you can get by cheap and easy until (and if) he gets into other more complicated projects.

 

of course if you are doing other more delicate things then then a nicer tool becomes necessity. nicer iron is always better, but not a necessity, IMHO, for soldering a few wires now and then.

 

jeff

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cteno4
Not wishing to hijack the thread but if you have any interesting circuit diagrams Jeff, I would always be interested too :)

 

Lawrence,

 

the stuff i was going to send is very simple stuff with battery or power supply, switch, pot, and some simple connector systems. nothing very fancy! ive been meaning to write these up and do some good pictures to post.

 

jeff

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