Mini Clear Xmas Lights

[usher40351]

Is using mini xmas clear lights a good idea for lighting buildings on a layout. I have both color and clear xmas min lite set and what about all red mini lites. 

[BlueHillsCPR]

Is using mini xmas clear lights a good idea for lighting buildings on a layout. I have both color and clear xmas min lite set and what about all red mini lites. 

Sure you can use mini lights.  Just make sure to use the proper stepped down AC voltage for the individual bulbs and don't use 117-120v AC line voltage at all on the layout for lighting, IMO.  Use AC from a powerpack or other low voltage supply.

I don't know that the red ones would be too useful...? 

[shayfan84325]

Sounds like good idea, with pitfalls to consider:

I've never been impressed with the quality of these lights, so be sure you can get to them to replace the dead bulbs.

I suggest that you run them at much lower voltage than their max.  If there are 10 bulbs in a series (and the series runs on house current), you can figure each bulb is designed for 12 volts.  I'd try them at 6 to 9 volts, and use AC - that will help them to last.

If you're doing this because real model bulbs are too pricy, I suggest you search ebay; there are often good deals there.  By the way, I've had good luck removing the color from colored bulbs using acetone (nail polish remover).  Often colored bulbs sell for less than clear ones.

[BlueHillsCPR]

Sounds like good idea, with pitfalls to consider:

I've never been impressed with the quality of these lights, so be sure you can get to them to replace the dead bulbs.

I suggest that you run them at much lower voltage than their max.  If there are 10 bulbs in a series (and the series runs on house current), you can figure each bulb is designed for 12 volts.  I'd try them at 6 to 9 volts, and use AC - that will help them to last.

If you're doing this because real model bulbs are too pricy, I suggest you search ebay; there are often good deals there.  By the way, I've had good luck removing the color from colored bulbs using acetone (nail polish remover).  Often colored bulbs sell for less than clear ones.

Indeed run the lights at a lower voltage.  You will find they last much longer if powered at 50%-60% rather than full power.  That's right, AC as long as it's stepped down is a good choice...wasn't thinking there!

The acetone is a good idea.  I'll have to try that!  Thanks.

I think the best deal I have seen on GOW bulbs is from Micro Mark at $42/100.

Grain Of Wheat Bulbs

 

Here is a link to some lighting power supply circuits if anyone is interested. 

[shayfan84325]

I once got 50 GOW bulbs for $4 plus $2 shipping on eBay (my favorite hobby store).  They were old, cloth insulation, but they work great.

[BlueHillsCPR]

I once got 50 GOW bulbs for $4 plus $2 shipping on eBay (my favorite hobby store).  They were old, cloth insulation, but they work great.

That's not a deal!  That's a steal!

[Texas Zepher]

Is using mini xmas clear lights a good idea for lighting buildings on a layout.

I've used them for over 35 years since they first came out.  My first "permanent" N-scale layout in 1970 was lit using the bulbs from one set.  Just adjust the voltage according to the number of lites in the string, subtract a bit, and they will last almost forever.

15 bulbs / 120V = 8 volts each
20 bulbs / 120V = 6 V
35 bulbs / 120V = 3.4 V    Run them at 3 V
50 bulbs / 120V = 2.4 V    Run them at 2 V

They will produce less heat when run at lower voltage also. 

[larak]

What they said with one minor correction. AC does not make bulbs last longer, DC does. This is for two physical reasons both having to do with movement of the filament. In any case do run the bulbs below rated voltage. It adds life, creates less heat and looks more realistic.

Karl 

[shayfan84325]

What they said with one minor correction. AC does not make bulbs last longer, DC does. This is for two physical reasons both having to do with movement of the filament. In any case do run the bulbs below rated voltage. It adds life, creates less heat and looks more realistic.

Karl 

Karl, With all due respect, we might both be right.  This comes from the University of Pennsylvania:

"As tungsten atoms evaporate from the filament, a very small percentage of them are ionized by the small amounts of short-wave ultraviolet light being radiated by the filament, the electric field around the filament, or by free electrons that escape from the filament by thermionic emission. These tungsten ions are positively charged, and tend to leave the positive end of the filament and are attracted to the negative end of the filament. The result is that light bulbs operated on DC have this specific mechanism that would cause uneven filament evaporation.
This mechanism is generally not significant, although it has been reported that light bulbs sometimes have a slight, measurable decrease in lifetime from DC operation as opposed to AC operation.

In a few cases, AC operation may shorten the life of the bulb, but this is rare. In rare cases, AC may cause the filament to vibrate enough to significantly shorten its life. In a few other rare cases involving very thin filaments, the filament temperature varies significantly throughout each AC cycle, and the peak filament temperature is significantly higher than the average filament temperature.

Ordinarily, one should expect a light bulb's life expectancy to be roughly equal for DC and AC."

Best regards,

[BlueHillsCPR]

What they said with one minor correction. AC does not make bulbs last longer, DC does. This is for two physical reasons both having to do with movement of the filament. In any case do run the bulbs below rated voltage. It adds life, creates less heat and looks more realistic.

Karl 

Karl, With all due respect, we might both be right.  This comes from the University of Pennsylvania:

"As tungsten atoms evaporate from the filament, a very small percentage of them are ionized by the small amounts of short-wave ultraviolet light being radiated by the filament, the electric field around the filament, or by free electrons that escape from the filament by thermionic emission. These tungsten ions are positively charged, and tend to leave the positive end of the filament and are attracted to the negative end of the filament. The result is that light bulbs operated on DC have this specific mechanism that would cause uneven filament evaporation.
This mechanism is generally not significant, although it has been reported that light bulbs sometimes have a slight, measurable decrease in lifetime from DC operation as opposed to AC operation.

In a few cases, AC operation may shorten the life of the bulb, but this is rare. In rare cases, AC may cause the filament to vibrate enough to significantly shorten its life. In a few other rare cases involving very thin filaments, the filament temperature varies significantly throughout each AC cycle, and the peak filament temperature is significantly higher than the average filament temperature.

Ordinarily, one should expect a light bulb's life expectancy to be roughly equal for DC and AC."

Best regards,

This is just the sort of thing that should be going on in a new forum dedicated to electrical and electronics!  Awesome information!  These are the discussions that end up getting buried by the diner and state of the onion threads.

[tomikawaTT]

I am using miniature Christmas tree lamps (from 300 bulb icicle strings) for a lot of lighting on my layout, so my experience might prove useful.

The individual lamps are rated 2.5V, but I run them on 1.6V (four in series, 6.3V source.)  At the lower voltage, they give a yellowish light that is prototypically correct for most structure lighting in my modeled time and place.  Power is provided by a 3 amp center-tapped filament transformer, which provides two circuits with ample capacity to light a small town.  Since they are push-in type, changing them will be no big thing - and with only four in series, finding the dead lamp will be no particular problem.  (They operate 50 in series on 120VAC, which could be hazardous.)

By varying the number of lamps in series, the same method can be adapted to almost any power source (5V wall wart, 16VAC toy train transformer...)  Just keep the voltage in the 1.5 - 1.75V/lamp range to extend life and minimize the bother of changing them out.

I considered putting a resistor in series with a single lamp, but at 2.5cents/lamp (Christmas clearance sale, I bought a dozen strings) three lamps cost less than a 12.5 cent resistor!

Chuck (modeling Central Japan in September, 1964)

[jxtrrx]

I use them, too -- just as described above with excellent success.  I often put a couple or more inside a building leaving a room dark here and there.  I also add a colored one (sparingly) to provide a different tint to different buildings.... but always with a clear or two alongside.  Amber is especially good if you can find them.