Question: Accessory Power Needs

[Anonymous]

I've got a question about accessory (i.e. non-train) power needs. Specifically, how should one determine the transformer power required for a given set of accessories?

In my case, I have a bunch of buildings each with a small bulb, a motorized crane, an intermodal crane, and couple of operating accessories such as the MTH fire station, operating station platform, crossing signals, and others yet to come. Will an 80w Lionel transformer power all these without trouble?

I'm actually interested in knowing how to arrive at the answer, but have not found it in the introductory wiring books. Nor do the accessory manuals or operating instructions say how much current an accessory requires or how many watts it consumes. Where can that information be obtained?

Thanks in advance.

Bob

[willpick]

Quick answer: your 80W transformer will power most of your list of accessories. Longer answer: EACH accessory will work correctly at a DIFFERENT voltage. To find out how much voltage and current each accessory needs for proper operation, you need a digital meter that has AC volts & amps ranges that match what the accessory instructions reccomend. For O scale stuff, the usual voltage range is 12-18VAC. Most accessories will draw less than 1 amp current-- but I like to know how much each one uses, so I can size the wires, etc.
I use a Radio Shack Digital meter and a voltage/current interface box that I built so I could measure each accessory's vital statistics.
Basically, for lighted buildings I run them at 1/2 the suggested voltage, as this makes them look "normal"(the building is lit, but it's not lit up like a searchlight). I do the same for each accessory-- use enough voltage to assure proper operation, then measure the current.
As for finding published data, very little factual information exists, but there are generalized wattage numbers for lighted buildings & passenger cars. I don't have the numbers at hand, but I'm sure somebody on the forum does[:)] I'm not aware of a list for action accessories.
Hope this helped!

[Anonymous]

While I'm happy with my 2 CW80's, I use them to power my 2 loops. All other power is from a new Lionel Accessory Transformer...about $25. With it, you can dial-up the ammt. of power you want (lighting levels, etc.). Joe

[Buckeye Riveter]

This is the way I have mine wired, as of today.

I use a separate accessory transformer, 14 v and 18 v output. The 14v side runs the majority of the accessories including signals, sound affects, building lights, etc. The 18v side is running only two accessories that are made to run at that high of voltage, the Hobo Water Tower and the Burning Switch Tower and even then the Switch Tower has some restrictions.

The instruction book that came with the accessories will tell you the max voltages that you can use. I'm only seeing newer accessories hit the 18v mark, but I guess there could be some older accessories that could handle the higher voltage.

KISS[:D][:D]

[lionelsoni]

If you don't have an ammeter, you can find the current for some lighted accessories from the lamp specifications. Here are some:
50 and 51: 7.5 V 220 mA
52: 14.4 V 100 ma
53: 14.4 V 120 mA
1445 and 1447: 18 V 150 mA or 14.4 V 135 mA
When used at other voltages, the current varies as the .55 power (approximately the square-root) of the voltage.

Keep in mind that some accessories draw current only briefly, like a switch machine or a crossing gate; so you need to plan only for the current drawn by the biggest ones that could be on at the same time.

To reconcile different voltage requirements, a lot has been written on the forum about using rectifier diodes in series to lower the voltage where needed. If you decide to do this, remember that ordinary voltmeters and ammeters will not read the reduced voltage accurately. A simple way around this with lamps is to switch the lamp quickly from the circuit with the accessory voltage and the series rectifiers to a simple variable transformer, adjust the transformer until you can't tell the difference, and then make your measurements with the clean sinewave from the variable transformer.

[Anonymous]

Thank you all very much for the prompt help, I greatly appreciate it. You've inspired me to move forward instead of putting it off for another evening, and so I'm doing some wiring tonight.
.
Again my thanks to each of you.

Bob Westbrook
Rice Owl, Houston TX

[Roger Bielen]

I sovled my accessory power needs with a 12.6vac, 10 AMP (yes amps) open frame transformer I bought from one of the mail order electronics stores. It'll give me more accessory power than I will ever need.

I use my original Lionel type "S" transformer for those accessoried I want on an adjustible voltage. My TPC400 with two 180W PHs is strictly for track power. If I decide to run conventional I can toggel over to my original TMCC 135WPH and PM that can be connected to either of the two loops, saves having to change the TPC over and thus the whole layout.