I am continuing to wire up the buildings on my layout and want to make a few calculations prior to wiring the MTH buildings.  How many amps or watts are consumed with each of the bulbs in an MTH building (these are the grain or wheat type, like from a strand of Christmas tree lights)?  Let me know what voltage the amps are at as well.  2nd question, is there a suitable LED replacement bulb (preferably one that drops right into the existing MTH building socket would be great.

Original Post

Are you referring to the CI-0000009 per the MTH bulb chart?

If this is indeed the bulb you're referring to, take a look at this recent OGR thread where member Arnoldoo mentions using the LED-8352WW to replace the incandescent bulbs in an MTH house.

There appears to be some issue with the shape of the plastic base.  If you do go this route, please post progress to this thread to add to the collective knowledge.

And based on a sample of 2, I measured an MTH passenger car bulb.  1.5 Watts at 14V DC, 2-1/4 Watts @18V DC.  The relationship between AC and DC power measurements is tedious but these numbers should head you in the right direction.   For the design of the LED-8352WW as shown in the linked thread, I'd estimate a ~5x savings in power.  It's a tedious technical discussion as to why you don't get more power savings so I'll leave it at that.

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Last edited by stan2004

Stan, thanks for the reply.  That is exactly the bulb I am referring to.  They use it as well in their buildings.  Wow, 100 mA per bulb, that is quite a bit.  A typical grain of wheat is about 65 mA.  So a hi-rise MTH building would take over an amp to run.  I think I will have to invest in the Town & Country LED's.  I was thinking they may be the ones that have them.  Doesn't seem like much work to modify the base of one of the mth sockets from what the other gentleman said in his post.  I have a high current probe that only goes down to 100 mA, maybe I can power a whole building with the current probe and see the total amps per building.  I will try it by the weekend and post my findings.

Thanks again.

Steam Loco Greg posted:

... I have a high current probe that only goes down to 100 mA, maybe I can power a whole building with the current probe and see the total amps per building.  I will try it by the weekend and post my findings.

Is this a clamp-on/clip-on open-jaw current probe?  If so, loop the wire thru the donut to increase sensitivity.  For example, 10 loops of wire increases the measured current by 10x so now the probe goes down to 10 mA in the last digit...and obviously mentally move the decimal point so to speak.

You are probably going to have to take the MTH buildings apart to replace the bulbs. I have a number of the buildings, and they drew a lot of power. Rather than replace the bulbs, I removed them and hot glued LED strips in the roofs. They work great, and draw a lot less power. While the buildings were apart, I also hot glued little people inside and on the sidewalks.

Gerry

gmorlitz posted:

You are probably going to have to take the MTH buildings apart to replace the bulbs. I have a number of the buildings, and they drew a lot of power. Rather than replace the bulbs, I removed them and hot glued LED strips in the roofs. They work great, and draw a lot less power. While the buildings were apart, I also hot glued little people inside and on the sidewalks.

Gerry

I did the same thing with my buildings too.

Stan, all,

Got the LEDs from Town and Country and am quite pleased with them.  For the 6 buildings in the picture below I reduced amperage from 3 amps to about 0.3 amps.  Note, not all of the buildings take the Christmas tree plastic base (Menlo, Susquehanna, Police Station, Jahn's), the other use the bayonet style (bank, diner).    Note the Menlo and Jahn's have extra stories and so they take about 20 and 14 bulbs respectively.  In the picture below all of the 6 buildings have the LEDs except for the Menlo building so you can see the color difference.  The transformer is about 15 or 16 volts.  I didn't get a picture of the Menlo building yet since it took quite a lot of time to do.

Yes, the Christmas tree LEDs are a perfect fit for the MTH buildings.  The one trick you have to remember is that since they are LEDs, position is important.  They will light in one direction and not the other.  Forgot about that fact until my handiwork reminded me of it and had to disassemble the buildings again.  Note, a number of the MTH buildings just have 2 black wires, so you need to test to make sure which side is power and which ground, and to make sure MTH didn't switch the polarity on any of the wires at different stories of your building (ran into that one).

Overall I am quite please with these and will get some more from Town and Country.  Also, ordered a 5 amp power supply I can set to 15 volts to power all my buildings now throughout the layout to make it easy.

Thanks for the suggestions.

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Steam Loco Greg posted:

Stan, all,

...The one trick you have to remember is that since they are LEDs, position is important.  They will light in one direction and not the other...

So to be clear, you are using a DC output power source for your building lighting?

For guys using the Accessory 14-16V AC output from some train transformers, the LEDs should light when plugged in either way.  Note that if willing/able to go DC, the cost of DC lighting power is substantially less than using AC.  A \$1 female screw-terminal adapter can be used so as not to splice/strip the cable/connector from the laptop charger.

When you use 14-16V Accessory AC power from a train transformer, you are "stealing" from the available Track motive AC power.  So, for example, if your lighting uses 50 Watts from Accessory AC, that's 50 Watts less power available to run trains themselves.  Note that a Watt of AC power from a train transformer can run you up to \$1 per Watt, while a Watt of DC power from a laptop charger or PC supply might be closer to 10 cents per Watt.

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