Street and Structure Lighting

[jonathan]

In the "learn-by-doing" style, I have been lighting up streets and structures.  And as usual, I have a few questions.  First the fun part.

This is my Olde Towne, tourist trap area.




This is the turntable as part of my junction.


The yard lights are scratch built from leftover stuff.


The technical part:  
I've attached bus wires to the DC side of a Tyco power pack.  It's max output is 6 volts (yes, it's old).  Figured the bulbs would last longer with less juice.  I soldered feeder wires to the bus wire which connect to the bulb wires.  I'm using traditional 12 volt GOW bulbs.  Lights are connected in parallel.

Questions:

Can these bulbs melt plastic structures?  I can feel heat (warm to the touch) on the roofs and tops of street lights.  I tried to keep the bulbs about an inch away from any part of the structures.

Can I burn out the power pack easily?  I have to turn up the power all the way for the bulbs to shine with any brightness.  In this case, I think replacing the power source would be easier, and cheaper, than bulb replacement.

Is it better to solder the bulb wires to the feeder wires?  In some cases, I have not soldered the bulb wires to the feeder wires, thinking it would be easier to replace the bulb, if and when it becomes necessary.

Finally, what is the limit of bulbs I can connect to the bus wire?  I have 15 bulbs connected so far.  My guess is things will start to look a little dim, if I connect too many bulbs.  I still have a few more structures I would like to light from this power source.

Originally, I wanted to get a rheostat and connect to the AC accessory side (18V).  Turns out small rheostats are hard to find.  Even Radio Shack doesn't carry 'em anymore.  I wanted to control the brightness, rather than mess with resistors.  I'm weird like that.

Thanks for reading.

Regards,

Jonathan  

[full maxx]

can't answer your questions but I can comment and say it looks great....wish I could make it look that good

[jonathan]

Thanks, Maxx.

There's a little trial and error involved--both in the construction and the photography.  I took about 30 pictures to get 4 or 5 that looked pretty good.  I played with the pics to enhance the color a bit.  Hiding the bulbs and wires was fun, too.  Don't look under the benchwork.  It's scary.

Regards,

Jonathan

[pdlethbridge]

been there, done that

[lmackattack]

Great pictures and scenery work. It looks very real. Nice job!

I have a few bulbs that are simply glued into a hole in the building. I run the voltage around 8V and have not had issues melting the plastic. If you run a full 12 things may heat up.

one pic shows some exterior lights on buildings
and the other shows my plastic street lamps fully enclosed with bulbs.

no issues so far!

[full maxx]

yeah I have a total of 8 switches and 4 power hook ups and it looks rough under my table as well

[jonathan]

Imackattack,

Great shots!  Your industry looks real to me.  Looks like a potential 'trackside photo' contestant for an MR mag.  They'd probably want you to string lines on your telephone poles, to get published.  I like it alot (sic).

Regards,

Jonathan

[Michael T.]

Wow... great scenery.

[Jim Banner]

Somewhere on your Tyco power pack should be a rating, usually in volts and watts or in volts and volt-amperes.  Both watts and volt-amperes are volts multiplied by amps.  Putting it another way, if you divide the watt or the volt-ampere rating by the voltage, you will get the maximum number of amperes (amps) you can draw.  Suppose (and this is only a wild guess) that the rating is 6 volts, 9 volt-amps.  Then the maximum current is 9 divided by 6 = 1.5 amps.

You can use any combination of loads (lights, motors, heater as in smoke units, etc.) that you like as long as their total draw does not exceed that maximum number of amps.  In our example, suppose you were using 12 volts Grain of Wheat bulbs that draw 65 milliamps (= .065 amps) each at 12 volts.  At 6 volts, they might draw .045 amps each.  Then a 1.5 amp supply could power 1.5 / .045  = 33 bulbs.

If all of this is a bit confusing, let's back up a bit and look at the three electrical terms I used above - volts, amps and watts.  But let's look at them in an easier to understand format, that of a water system.  Let's make that water system a water tower at a railroad station.  And connected to that water tower is a valve, down at ground level, for drawing water out.  The higher the tower, the more pressure that is available at the tap.  The pressure of fluids is often measured in pounds per square inch or p.s.i.  A 23 foot tower produces about 10 p.s.i.  A 46 foot one about 20 p.s.i.  And so on.  Now consider next to the tower a pile of batteries, stacked end to end.  The more batteries we have, the more electrical pressure we can generate.  This electrical pressure is called Electro Motive Force (E.M.F.) or electrical potential and is measured in volts.  Very often, electrical pressure is referred to as voltage, at least when you are measuring it in volts instead of one of the other units.  Bottom line, water pressure (in p.s.i.) is similar to voltage (in volts.)

Using that same water tower, we can let the water out at a faster or slower rate depending on how far we open the valve.  If we open it only a little bit, it might take 10 minutes to fill a one gallon bucket.  We can say that the flow is .1 gallon per minute.  Open the valve further, we might fill a 5 gallon pail in 1 minute with a flow of 5 gallons per minute.  The pile of batteries works much the same way.  If we put a small load on it, we might create an electrical flow of .1 amperes (amps) while a larger load might create a flow of 5 amps.  With electricity, we also use the term current when we have a flow and the term amperage when we measure the flow so we could have said a current of .1 amps or an amperage of 5 amps.  But a flow of what?  Well, electricity is a flow of electrons moving through the wire.  And an amp or ampere?  That is a flow of about 6,241.510,000,000,000,000 electrons per second.  Bottom line, water flow (in gallons per minute) is similar to electrical current (in amperes.)

So what's a watt?  Power is how hard something has to work, or more formally, the rate of using energy.  For our water tower, that would be the flow multiplied by the pressure.  This is not too obvious when we draw water out of the tower but is much easier to understand when we look at what it takes to put it there is the first place.  In the days of steam, most water towers would have a pump man whose job it was to keep the tower full.  To do this, he might have a steam driven pump taking water out of a creek or a well and pushing it up to the water tower.  The more gallons of water that the pump had to pump every minute, the harder is had to work.  And the higher the tower, the harder the pump had to work for each gallon it pumped up there.  Now maybe the flow (in gallons per minute) multiplied by the pressure (in p.s.i.) makes more sense.  Throw in the right factor and you get horsepower or a different factor and you get watts.  With electricity, the power is the flow or current in amps multiplied by the pressure or potential in volts and the answer is directly in watts.  Dividing by the factor 746 will give you the power in horsepower.  Bottom line, the power used or produced is the flow multiplied by the pressure and by a suitable constant with both water and electricity.

Before we leave this analogy, consider what happens when we try to take water out of the tank at a faster rate than the pump can fill it.  At some point the system fails.  Maybe the pump blows a gasket or the creek dries up or whatever.  Trying to take more power (watts) out of a power supply than it can deliver will also result in a failure.  If we are lucky, all that does is open up an automatic circuit breaker.  If not, then out comes the magic smoke.

Jim

I got so busy talking the technology that I forgot to comment on the art.  They are great lighting effects and wonderful photographs that capture them.  I too believe that you should submit one or several of them and if the editors refuse them on the grounds of wireless poles, it will be their loss.

[Doneldon]

jonathon -

Wow! Professional looking results, both the models and the photos.  I'm impressed.

You kind of have to go by trial and error on the melted plastic question.  Just watch things closely so you can see if problems are developing before they get severe.  Twelve volt bulbs running on six volts shouldn't get excessively hot, but I do notice that your lights are awfully bright.  I wouldn't just keep adding more bulbs as a way to dim them as that might lead to a failed pack.  Don't forget to check around your home for various wall wart survivors from old electronics, cameras, cell phones, toys, etc.  These can be put to work on model railroads for free and multiple circuits will stave off overloads.  Plug them all into a power strip with a switch so you only have to throw one switch or pull one plug out of the wall.

One suggestion: Some of your lights seem overly bright, possibly because you used a time exposure.  If that's the case, ignore what I'm about to say.  If not, take a walk around the block after dark tonight and see how much light escapes from your neighbors' houses.  Then take a ride through a commercial district and an industrial area and carefully observe brightness there, as well.  For the most part, light from windows isn't very bright and exterior lights still leave a lot of darkness.  As with so many model things, less is often more.

But it's clear you have a gift, or several gifts, so I encourage you to continue modeling and playing with light and photography.  Like several other responders, I encourage you to submit some photos for publication.
                                                                                             -- D

[J3a-614]

Great advice from both Donaldon and Jim, especially the comments from Jim about electrical theory; this is part of what is in Wescott's book about wiring.  I seem to recall Atlas has a wiring book, too; it's obviously geared to their components, but what they offer are mostly electical switches in various combinations for surface mounting, so there is no real difference in function, other than thay they also group some switches into certain combinations.

And of course, I have to mention you are making me jealous. . .you have a railroad with scenery and lights. . .

Thanks for posting.

[jonathan]

Jim,

You ought to write a manual on electricity.  The water flow analogy helped me to understand immensely.  Fortunately, the analogy doesn't require a lot of math so I wasn't drowning after reading your explanation.  A simple equation (dividing the output amps by the amp usage) seems pretty straight forward.  I'll have to go back and see how many milliamps these bulbs draw. 

The AC side of the pack will power the flashing lights on my crossing gate, when I get around to installing a flashing circuit.

As far as brightness goes:

My wife's digital camera automatically adjusts itself, so it performs a timed exposure in a dark setting.  The camera gives off a slow click.... click sound when the exposure goes slowly.  So, the brightness of the lights is due to the camera's auto settings.  If you saw the lights in person, they wouldn't look nearly so bright.  I also brightened the shots, on the computer, when I downloaded them.  Notice the backdrop is visible, even though the room was not lit.

I actually intend to submit some photographs someday.  There will need to be more details in the scenes.  Plus, I will have to replace the $1 Walmart autos with more era specific vehicles.  And the mags require 12mb digital photos.  This camera is only 10mb.  I think Imack is closer to the submission phase than I am.

I have noticed, on the trackside photos, that the published scenes seem to be slightly out of focus.  Also, everything in the scene seems to be slathered in dullcote and weathering.  I guess that's part of the illusion of realism.

Regards,

Jonathan

[Colorado_Mac]

Jonathan and Imack -
Swe-e-e-e-e-et!!