I am planning on installing interior lighting to my Canadian Pacific Heavy Weight Passenger cars:
I am planning on using a 470, 25v capaitor to keep lights from flickering:
Thank you
Brian
Are you using DC or DCC? Most LED’s operate in the 2-3 voltrange maximum. Are you goingto use rail pick-up for the lamps or battery? As far as color, the warm white would be consistant with an incondescent lamp.
Jim
[quote user=“brianmarie”]
I have a DC layout and am planning on installing interior lighting to my Canadian Pacific Heavy Weight Passenger cars using wheel pickup.
I am planning on using a 470, 25v capaitor to keep lights from flickering:
Thank you
Brian
Warm white would be consistent for a modern incandescent lamp operation at full rated voltage on household AC - or a modern passenger car lighted from HEP.
For an older heavyweight, the battery/generator system would usually produce a yellow light, especially when the car was standing still and the lamps were only getting discharge DC voltage.
I use this on my layout. The EMU and HEP-rigged DMU have bright interior lighting because their lamps would have been getting steady high voltage. The conventional cars and standard DMU have the older DC generator plus batteries - and dimmer, yellowish lighting. The only difference is that the DMU drive the DC generator off the car’s prime mover, while the unpowered cars have axle-driven generators.
Chuck (Modeling Central Japan in September, 1964 - steam, diesel and catenary locos without HEP)
Brian:
For your DC setup adding a bridge rectifier will provide for directional lighting. Connect the AC terminals to your track pickups and take your DC feed from the + and - terminals. Any small bridge will work as long as the amp draw of your LEDs is less than the rating for the bridge. The rated voltage for the bridge should be more than your track feed.
Joe
I use this item with good results. It’s rated at 1.5 amp, 400 volts so plenty of overhead for your purpose.
All-Electronics FWB-15: http://www.allelectronics.com/make-a-store/item/fwb-15/1-1/2-amp-400-piv-full-wave-bridge-rectifier/1.html
RS equivalent is 276-0268.
This is an install in a Walthers Pullman. I take over the bathroom or vestibule at one end of the car, use the car’s built in wipers if possible, and use the # of LED units (usually can be cut to 3 lamps per segment) I need wired in paralell.
I’ve written up my work at these two links, I think the passenger car lighting is on page 2 with both.
http://cs.trains.com/mrr/f/88/t/213765.aspx?page=1
http://atlasrescueforum.proboards.com/thread/2132/cheap-updating-tomar-drumheads-lighting?page=2
I also recommend the warm white for your pupose. In any case, you can depend on adjusting the resistor to get your levels set, but some you do by engineering the location and baffling if you want variance as in Pullmans with compartments. I describe doing that, but glad to answer any questions.
A DC install is going to act differently than a DCC one. Not sure exactly how, but if you get stuck, there’s a good crew of folks over in the Elec. and DCC forum and we’ll figure it out for you.
Subway Trains of LION use blue-white lamps to simulate the florsecent lighting of such equipment. Older cars might use warm-white LEDs to simulate the incandescent lamps of that era.
But what on streamlinesr? The lights are usually turned off so that the pax can sleep. There are normally only some incandescent foot lamps throughout the coach. The big flourscent lamps would only be turned on the the terminals where there is a lot of hub bub and no sleeping.
As for the rectifier : DC or DCC is no matter, you need a full wave bridge rectifier to control your power. The AC connectors to to the tracks and the DC outputs go to your lighting bus.
LION is looking at 1 Farad capacitors to keep the lamps lit while the train is stopped in the station. Since these Super Caps are 2.5 volts, LION will have to wire five of them in series to give them a 10 volt capacity. If I need more than 1 Farad to keep the lights on a second bank of 5 caps will be added.
There are 4.7 Farad caps but putting five of those in series may be more than the little 50’ subway cars can handle.
ROAR
To model a car with incandescent lights, the best results are had by using miniature incandescent lamps. If you are dead set on using LED’s, a warm white LED is best. If you are modeling a car with flourescent lighting the blue white LEDs look pretty good. A 470 ufd capacitor is way too small to surpress flicker. You need 0.47 Farad or better. You can get them from All electronics. I did this once and it kept the lights on for 20 seconds after track power was removed.
The simpliest rig, 12 volt incandescent bulbs, which work fine for either polarity, and a DC layout, just wire the bulbs to the wheels and you are good to go.
LED’s are polarized. Give 'em juice the right way round and they light up. Give 'em juice the wrong way and they pop. So a LED installation needs a rectifier. Radio Shack sells 'em. Any full wave bridge rectifier made will easily handle a model railroad car. LEDs need a current limiter to hold their current down to 10 mA. A 1000 ohm resistor is just right.
You can keep the brightness steady with a voltage regulator. All electronics has these too. A 5 volt regulator is about right. The regulator will take in rectified track power which varies from zero to 12 volts, and output a steady 5 volts as long as track power is above 6 volts. With 5 volt power to the LEDs try a 120 ohm current limiting resistor.
Note to Lion. You can get 5 volt supercaps. I would put in one 5 volt super cap, and use a 5 volt regulator to keep it happy. Then run the car lights on 5 volts. On the other hand if you have 48 wheel pickup, why do you need a cap at all?