Passenger car lighting?

[Anonymous]

I want to experiment with adding interior lights using an old Lenz 100 decoder and some LEDs (plus resistors and a capacitor for simulating motor draw) in the interior of a car or two.

If I want to light up say 3 LEDs would I wire them in series or parallel?

Would 3 or 4 LEDs on one function lead of the old decoder be too much, or is there no limit?

This is a budget experiment with leftovers.  I know lighting strips exist for this purpose.

Am I going to get acceptable results without using these kits?

[locoi1sa]

 I would try parallel on the LEDs. Put a resistor in one leg of the buss. As for a fake motor all you need is resistance. The cap would be put across the light buss to keep the LEDs lit while on dirty track and loss of contact.

     Pete

[dstarr]

 Why bother with the decoder?   Let the passenger car lights run as long as the car is on the track.  With DCC the power is always on, and of the same voltage whether the train is moving or not.   Try some 16 volt incandescent lamps.  Test 'em out by hooking them across the track before taking the cars apart.  Lamps work fine on AC or DC.  And the color is right.  In a car you want more than one lamp.  Hook them in parallel. 

LED's are harder. LED's only work on DC, so the car needs to carry a rectifier and each LED needs a current limiting resistor of probably 1K.  Plus the color is awfully blue.  

[rrinker]

 I wouldn;t even put the resistor in the car, just clip it on the motor leads to program and then it's not needed. If you do keep the resistor, you need a fairly robust one, a simple 1/4 watt one will not handle the power from the motor output. Also program a 28 step speed table with all steps at 01 so in case you do select the address and crank the throttle, the output remains low.

 OH and golden white LEDs liek Miniatronics Yelo-Glo aren't the slightest bit blue.

                            --Randy

 

[CSX Robert]

Cisco Kid

...Would 3 or 4 LEDs on one function lead of the old decoder be too much, or is there no limit?...

There is a limit. Would 3 or 4 be too much? Most likely not, but it really depends on three things: the current limit of the function output, the current at which you plan to operate the LED's, and how you wire up the LED's. Since you'll probably be operating the LED's at less than 30mA and most decoder function outputs are capable of sinking at least 120mA, you should be alright.

Cisco Kid

If I want to light up say 3 LEDs would I wire them in series or parallel?

I would wire them in series. Wired in parallel, you would need one resistor for each LED(you might get by with one resistor for the circuit, but it's not good practice), but wired in series, you only need one resistor. Wired in parallel, the circuit will consume three times(or however many LED's there are) the current(three LED's wired in parallel to operate at 10mA would draw 30mA, three LED's wired in series to operate at 10mA would only draw 10mA).

[MisterBeasley]

Remember that LEDs are very directional.  They throw a beam, like a headlight.  That's why you'll need a few of them to distribute the light evenly throughout the car.

It's true that you don't need a decoder to control the lights.  With LEDs in particular, the current draw is so small that it won't make much difference, and they effectively live forever when wired properly, so you don't need to worry about bulb life.  However, if you will use the cars "operationally" and will sometimes have them on a visible siding between trips, then turning the lights off is a nice effect.

You could also control the lights with a latching magnetic reed switch.  You would turn them on and off with a magnetic "magic wand."

Are you going to detail the interior of the cars?

[AntonioFP45]

 Guys,

Re: LEDs appearing blue................

Don't forget that the majority of streamlined cars built by Budd, Pullman Standard, and ACF were equipped with floursecent lighting in coaches, lounges, and diners in addition to the incandescent lights. Floursecents are standard in modern passenger cars.   So a blueish light for an interior wouldn't be far off the mark.  Additionally, depending upon the railroad, windows often had either a greenish or blueish tint.  

[DJO]

I bought some cars from Walthers now and was thinkin about gettng the lighting kits that go with them.  Are they good or do they fliker a lot like the cheap sets?  Are there any kits as good as the ones in 3 rail O scale?   Fp45 your right. The trains I rode years ago had florescent lights.