Wiring Lights on My Layout

[dc1]

I am very new to trains and have recently built my first fully landscaped layout that includes slot cars with HO Trains.  I have completed all tasks except the lighting and am have a difficult time figuring out how to power and install the lights.

 

The lamps I am using where purchased off of e-bay (See link below)

http://www.ebay.com/itm/RB150-20pcs-Model-Trains-Layout-Lamppost-lamp-HO-N-65mm-/250986774278?pt=Model_RR_Trains&hash=item3a6ffa3f06

 

They are 6V, 70mA lights.  I have a Railpower 1300 Hobby Transformer with the following specs:  Input:  120VAC 60Hz Total Output 7VA  Output:  15VDC, 19VAC.  I have run two seperate wires from the AC connection on the transformer and attached the two wires from the street light to these wires which does make them light up.  The problem is that they get so hot they are melting the plastic around them.

 

I know I need to make some changes but not sure where to start.  Do I need a new power source, resistors or something totally different.  I am not afraid to do thing right so please feel free to recommend the best solution.  I am installing 80 - 120 of these lights.

 

Thanks

Dave

[stevenh]

The issue is that the lights are only meant to receive 6vDC and you're feeding them up to 15vAC!

 

You're best bet is to first 'rectify' the voltage from AC to DC and then drop the voltage with an 7805 IC (will output 5vDC).

 

Here's a good circuit example: http://hassam.hubpages.com/hub/zpedia

Here's one showing the AC Rectifier: http://free-schematic.blogspot.com.au/2010/06/converter-circuit-240v-ac-to-5vdc-power.html

And again here, you'd need everything after T1: http://www.aaroncake.net/circuits/supply6.asp

 

Hope this helps.

[keitaro]

i'm not being rude but LOL

 

I came in here to post a reply and saw stevenh, cteno and inobu all posting in this thread and 7 other people viewing the topic and thought to myself this is going to be a battle of the first poster hahahaha

[inobu]

lol, yeah, me too. I thought surly I could not beat Jeff to the punch so I'm just sitting here. lol

 

Keitaro.....lol 

 

Inobu

 

 

[cteno4]

dave,

 

sounds like an interesting project.

 

thats quite a few lights to power!

 

good thing with incandescent lights like this you can power with ac or dc current. your power pack would not put out enough to power all your lights -- will need 7 amps to power 100 70ma lamps. you can easily drive them from a simple wall wart transformer. to do 100 of these would probably take a few of these as most times these transformers are like 2 or 3 amps max.

 

you can probably get away with using a 5v power supplies for these the lights will just run a tad dimmer, but you might actually want this as driving them at full power may be too bright. you could use a variable dc source like a train power pack, but again these are limited to around an amp or so around 6v. (the 7va rating is basically saying voltage x amperage = 7va) if you have any wall warts laying around that are 3-6 vdc range you might try your lights on them by just touching the wires to the plugs and seeing how they look. there are other more sophisticated ways to reduce the voltage if you want to get into that as well -- you can use a resistor to drop the voltage for each bulb but you end up with more components in the mix to deal with. the simple method would be to just use wall warts that are the voltage that gives you the brightness you want.

 

if you use a 5 or 6v transformer then you can just wire all the light bulbs in parallel.

 

i would first experiment with what ever voltage adapters you have laying around and see what gives you the right brightness on your bulbs first. then buy one that voltage and string up a group to it to see how it all looks. you also want to probably just wire different areas together of like 20 lamps into a single switch and 2A wall wart. you dont want to draw the max amperage of the transformer rating, give it some buffer of like 25%.

 

these are pretty cheap

 

http://www.ebay.com/itm/New-Home-AC-Wall-Power-Adapter-Charger-PSP-US-Plug-100-240V-DC-5V-2A-Brand-/370582275937?pt=Video_Games_Accessories&hash=item56486cc761#ht_4629wt_882

 

post some picts of the layout, sounds interesting!

 

cheers

 

jeff

[cteno4]

lol, yeah, me too. I thought surly I could not beat Jeff to the punch so I'm just sitting here. lol

 

Keitaro.....lol 

 

Inobu

 

 

 

LOL i didnt even notice others starting the their threads, just finished working on something and took a quick break to see what was up! well i just posted the simple answer!

 

jeff

[dc1]

Gentleman:  Thanks for such a quick reply.  I have already tried the solution of a 6v wall wart and it worked perfectly.  I have already wired around 20 lights.  I appreciate all the responses and the help.  You guys are quick.

 

Thanks

 

Dave

[cteno4]

Dave

 

Cool, glad it worked for you.

 

Just make sure not to overload the converter. The amperage is listed on it. I'd go only to about 75% of its rating to be safe. You might also check out a 5v one as well as running at a bit lower voltage might make the bulbs last longer. Also maybe really bright once you get all these going!

 

Enjoy

 

Jeff