# Powering lights



## DustinSS (Oct 22, 2006)

What can I use to power about 20 street lights on my track? They are o gauge (1/32 slot car track), and are 12-16v. With a regular lionel power pack, only 2 maybe 3 are bright. Is there something I can buy at the local hardware store or wizz-mart?


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## TK Solver (Mar 18, 2004)

A Malibu low-voltage outdoor light kit transformer might work economically. They vary from 100 watts up to 900 watts so there's probably one that would do the job.


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## Dslot (Sep 2, 2007)

DustinSS said:


> ...about 20 street lights ... 12-16v. With a regular lionel power pack, only 2 maybe 3 are bright.


Dustin,
The pack you have should handle the job, but you have to connect the lamps right. My guess is that you hooked them up in *SERIES* (see diagram example), that is:
_pack connected to bulb 1, bulb 1 to bulb 2, bulb 2 to bulb 3 and so on, with the last bulb going back to the power pack._
That way, the voltage each lamp gets is the pack's output voltage *divided* by the number of lamps. If there are more than a couple of lamps in the string, each bulb gets very low voltage and will be dim or dark. In addition, if one bulb goes out, they *all* go out until you find and replace the bad one.

A better way would be to hook the lamps in *PARALLEL*. Each bulb has its own direct connection to both the positive and negative terminal, so each bulb gets the full output voltage of the pack (as long as there aren't too many bulbs for the pack's amperage). Since the pack probably puts out 12-16 V, each lamp would be running right at it's maximum rating - nice and bright, but not for very long.

The best way might to combine the two for a *SERIES-PARALLEL* circuit. Pair up the lamps in Series, but connect each pair in Parallel. Each bulb will get _*half*_ the pack's output voltage. They will be a bit dimmer than on the pure parallel circuit, but running at half the voltage, they will last about ten times longer. -- D


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## Dslot (Sep 2, 2007)

Me said:


> The pack you have should handle the job ...


I may have spoken a bit too fast here. Relevant variables include:
 - The Amperage of the power pack,
- The types of bulbs being used,
- Whether the pack is being used for anything else besides lighting the bulbs.
- The size and length of the wiring to and from the lamps.

PACK AMPERAGE - Lionel packs are no longer the beefy things they used to be. The first modern Lionel pack I checked the stats on put out a wimpy 12 Watts at 16V (i.e. about 0.8 Amp). That would handle only 9 or 10 "grain-of-wheat" (GOW) type bulbs in Parallel. It would handle 18 to 20 if they were in Series-Parallel by pairs, as I described. For the larger screw-base or bayonet-base bulbs, maybe half that. [This assumes that the very old rule of thumb that a GOW bulb uses about 1/12 amp, is still valid. If recent bulbs are more efficient than this, you may be able to get a few more]. If your pack delivers 1.5 Amps or more at 16V (that would be about 25 watts or more) then you may be able to light 20 GOW bulbs in Parallel.

TYPE OF BULB - If your lights use something besides GOW bulbs, the number will vary. Rule of thumb said that "toy train" type screw or bayonet bulbs drew almost twice the amps of a GOW bulb. Don't know about the more exotic types.

OTHER DEMANDS ON THE PACK - If you are also using the pack to do something else in addition to lighting, then the number of bulbs it can handle will be decreased. 

WIRING - Resistance in the wiring will reduce the number of bulbs a given pack will handle. The longer the run between the power pack and the lamps (and between the lamps themselves), the more resistance there will be. The smaller the diameter of the circuit wire, the more resistance. Poor connections also increase resistance.

Note that wiring in Series-Parallel by pairs (see earlier post) will double the number of bulbs a given pack can handle over a straight parallel circuit (because each bulb is only seeing half the voltage and drawing half the amps). 

Rats! Nothing's simple in electrical hobbies.

-- D


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## Dslot (Sep 2, 2007)

Dslot said:


> Relevant variables include:
> - The Amperage of the power pack,
> - The types of bulbs being used,
> - Whether the pack is being used for anything else besides lighting the bulbs.
> - The size and length of the wiring to and from the lamps.


... And how many bulbs each streetlamp has. 

If each has two bulbs instead of one, then that's 40 bulbs and TK's 100-watt suggestion doesn't seem quite so much like overkill. 
-- D


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## DustinSS (Oct 22, 2006)

Thanks for all the info! I will try and get them up and running again this weekend. Thanks again Dslot!


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## roadrner (Jul 21, 1999)

Great little tutorial. Thanks! :thumbsup: :thumbsup: rr


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## videojimmy (Jan 12, 2006)

Great Info Dslot.. Thanks!


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## Bill Hall (Jan 6, 2007)

Hahahaha D-slot ...bless you!


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