I am a small time modeler, I have small N scale layout that i putter with when time and money allows. However recently I ran into something that is stumping me. One day while puttering my Lamp Posts (ModelPower 8482), literally Melt. Keep in mind these were ones that I had installed years ago, so i thought something had fishy had happened because they were older... I replaced them with new ones. When i turned on the new ones they got Extremely Hot extremely quickly... So next I suspected the AC power supply (ModelPower RL-1250) they were hooked to, which is fairly old. I Switched to a different RL-1250 power supply, same thing. I tested the AC output of both of the RL-1250 and it seemed fine. I am not sure what could cause this, anyone have any ideas?
Yup. Too much voltage. Is it the same transformer as before. Did you hook it up the same way?
Connect the lamps to the track terminals, and slowly turn the voltage up until the light is right. You can continue to use an old train transformer with the lighting, or you can buy some wall warts, perhaps a 5 volt wall ward, and use that for your lights.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Jim!
Often, the model transformers AC output is 16 volts. As you found out this will really cook a 12 volt bulb.
[edit] OUCH! I just Googled your Model Power transformer and the output on the AC side is 19 volts! Waaay too much for a tiny 12 volt rated bulb. And the DC side is 0-18 volts, also too high for the average N scale model locomotive.
Is THIS the guy???
You could use a "series-parallel" wiring scheme where you wire pairs of lamps in series then each group of pairs in parallel. They will last MUCH longer at reduced voltage.
Or, as LION suggests, you could find an old "wall-wart" type transformer and use it for your lighting supply. There are plenty out there from old electronic devices in the 9 volt to 12 volt range. AC or DC incandescent lamps don't care but LEDs do.
Good Luck, Ed
Another suggestion:
When you get a wall wart, check the output voltage before hooking any thing up, using a volt meter.
A bought two variable ones that put out 24 volts no matter what they were set at.
I was lucky that a friend warned me.
Dave
Hi JimBomm
Ok that gets expencive ouch! over voltage is the problem that will make them melting and burning out hot.
Simple solution is to have one or more lamps in series this will reduce the voltage
and will require some experementation as to number of lamps in series
The rest of the lamps are wired in parralel
You will know if one of the series lamps has gone because every lamp will go out.
Idealy you want to get the feed down to about 9 or 10V if it's 12V incandecant lamps.
This will extend the life of the lamps quite a bit and lower the brightness of the lamps often model lamps look better at a slightly lower light intensity.
regards John
Newer wall wards are switching power supplies and not transformers. A switching supply needs a load on it in order to have it respond to the correct voltages
Put an automobile tail light across it and then test the voltages.
Jim,
I actually prefer using a power pack for layout lighting as mentioned by Lion. I find powering 12V incandescents at 8-9V looks nicer, more realistic, and increases the overall life of them dramatically.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
make sure if you use a variable transformer to vary the voltage that it is a better grade one that uses an electronic circuit to lower the voltage & not a resistor or reostat in series with the output like some "toy" transformers do
another method is to use a doorbell transformer with a good grade lighting dimmer on the 120 volt side to reduce the primary voltage..the secondary voltage will drop proportionately. Use a volt meter to measure & set the secondary voltage to the desired level
i looked up the specs on those lamp posts they are rated at 30ma @ 14v
or .42VA each
on a 10va supply you can safely drive 20 of these lamposts at rated voltage