Need Help -- Power Requirements

[jimhaleyscomet]

Bob

I see you are in Houston Texas. Are you familiar with HTOS (Houston Tinplate Operator Society)? They run 3 rail O gauge and will be opening a new facility this month in the Memorial City Mall (Beltway 8 and I10) for running trains.

Jim H

[Anonymous]

Bob and Dale --

Many thanks for the very helpful electrical guidance on how to wire the LEDs. I will definitely make the changeover from incandescents.

I sincerely appreciate the help you've both provided, and hope I can reciprocate some day.

Best regards, and thanks again --

Bob Westbrook
Houston, TX

[Anonymous]

Bob

Those are the first and last letters of my last name. "H" was taken on the forum.
I do not know of a post on LEDs. I purchased mine directly from China. I have some 8mm "Warm White" in color with a forward voltage of 3.0 to 3.8 volts. with a viewing angle of 140 degrees. These cost about $1.50 each and to me are worth the extra cost. LEDs vary on how much reverse voltage they can take,I use the rectifier to be safe,this puts out a pulsed DC, no real need to smooth out the ripple as LEDs can handle it.

Of course you can always use a half watt resistor if you dont want to use 4 LEDs. Resistor value is input voltage minus forward voltage of the diode divided by the current the diode uses.

In passenger cars I simply use an adjustable LM350T regulator and set it for the forward voltage of the LEDs. In this fashion dropping resistors are not required for each LED. I solder the LEDs to N gauge track and stick the track to the floor of the car as well as a voltage regulator circuit. If you always run DCS or TMCC you do not need the voltage regulator.

Diodes (LEDs) are very long lasting and use considerable less power than conventional lightbulbs. On passenger cars it can also extend the life of contact blades and pickup rollers because there is less current draw and less arcing.

Dale Holzmann

"Dale Hz"

[lionelsoni]

For fixed-voltage lighting in buildings, I would use pairs of white LEDs, connected anode to cathode, with the pairs wired in series with each other and then in series with a ballast resistor. Each pair will drop about 4 volts. The peak transformer voltage is 1.4 times the RMS voltage and should be substantially higher than the total for the LEDs. You don't need a rectifier if you do it this way.

For example, 3 pairs of LEDS will come to 12 volts, which is reasonable for use with a 12.6-volt transformer output, whose peak voltage is 17.8 volts. The average current in each LED will be about 20 milliamperes with a 51-ohm ballast resistor.

I recommend the LEDs sold by Richmond controls (http://www.richmondcontrols.com/) that are a yellowish color much more like incandescent light, instead of the harsh blue of ordinary white LEDs.

[Anonymous]

Dale -- thanks very much for the information, it was exactly what I needed. I never thought of replacing all the building bulbs with LEDs to save on power, but will do so. Can you refer me to an article or posting that discusses how to do the replacement?

Thanks again.

Bob

P.S. I noticed the acronym after Dale ("Hz") -- is that as it the herz in electricity?

[Anonymous]

Building lamps,depends on the number of bulbs and the voltage you run them. The old #53 bulbs maybe 2 to 2.5 watts each. The minature bulbs about a watt each
Floodlight tower 10 to 15 watts depends on voltage applied. Most of these have 18 volt bulbs. I run everything on 12 volts.
Grade crossing signals with LEDs less than 1 watt
Accessories vary. MTH car wash 3 watts lit maybe 8 watts activated. An old style Lionel crane with magnet may pull 25 watts. Can motors pull much less.
For housing lights and passenger cars I would consider LEDs they use much less power. On a building for example with a 12 volt feed you could install a bridge rectifier and wire them in series of 4.

Dale Hz

Dale Hz

[Anonymous]

Can anybody please tell me the approximate wattage (or even range of wattage) for each the following accessories, so I can plan transformers needed? If memory serves me correctly, since watts = volts * amps, it should depend on the voltage in the circuit, so please also indicate the assumed voltage...

I've searched the forum and cannot locate the message I think was posted last year that gave some typical values.

Individual building lamp bulbs
Floodlight tower (e.g. 6 lamps)
Grade crossing signal (e.g. MTH powered by ITAD)
Track signals
Operating accessories (e.g. MTH car wash, Lio 14209 gantry crane, etc.)


Many thanks in advance to any who can help.

Bob
Houston, TX