here's what I have: Amtrak baggage car and 4 observations cars for static display (i.e., a diorama). my idea: 1. Energizer A23 (or equiv) 12V battery in the baggage car, manual slide or mini push button switch on bottom or on end. Energizer is rated 55 mAh 2. connect car to car with mini plugs, running 12V to each car 3. LED flex lighting strip with 9 LEDs/car (6 upper deck, 3 lower deck) - soft white 4. possibly 2 more LEDs in last car for red end of train lights or maybe just fiber optic from last LED to red lenses on back. It's been 50 years since I took DC circuits class, so I'm pretty rusty. the LED strips are rated at 7.2W/M (I'm assuming 7.2 watts/meter). The total length of LEDs for the 4 cars should be about 1 Meter the LED strips have resistors built in, but do I need another resistor to dim the LEDs at bit? If so, what size resistor. This seems easier than wiring up LEDs with resistors/diodes/driver etc. In the mean time I'm repainting the passenger car seating and adding passengers. Comments Please!
How about just using the Rapido Easy-Peasy car lighting kits? Here is link to the product at Fifer Hobby, also available at most of the major retailers http://fiferhobbysu770.corecommerce.com/cart.php?m=product_detail&p=15188
thanks for the idea. however, with upper and lower lighting in 4 cars, I'd need 8 kits. Plus 4x the batteries, plus 4 individual switches instead of 1 for the train. the link was for N, I neglected to say HO. I think build-my-own will work out significantly cheaper. But again, thanks for the response.
You don't need switches with Rapido Easy-Peasy just swipe the wand across the cars the switch is in the unit. The batteries are the same used in some hearing aids.
I'm looking for electrical advice. ie, use X gauge wire, add Y ohm resister, be sure switch is rated for Z amps, etc.
If you connect 1 metre of the LED strip to the battery without any additional resistor, the strip would draw 7.2 / 12 = 0.6 Amp. You battery would last about five and a half minutes! (0.055 / 0.6 x 60). You could reduce the current by adding a resistor, but I'm not sure even then that battery would last very long? You might be better off finding a lower power rating LED strip, and/or increase the battery capacity? Jim
I assume the 60 is for minutes/hour conversion. How about a standard 9V battery* rated 500mAh. If I did the math correctly that should work out to close to 12 hours, which is acceptable. That assumes the lighting strip would work at reduced brightness on 9V, (reduced brightness is fine for this application. I think the danger would be over-lighting, not under-lighting.) However, I'll check more on LED tape light specs. Thanks for the reply. Bob * EN22 Energizer 9V Industrial $1.48 ea. in lots of 10
I recall a production model of a CB&Q Budd Zephyr train set that came factory lighted. Looked like they used blue lasers inside. Almost hurt your eyes. Someone commented it looked like they must have been filming a movie inside.
If this is a static display, could you use a small wall-wart power supply (12VDC, 1amp) instead of a battery? get a small 2-wire connector plug
The calculation would be 0.5 / 0.6 x 60 (the 60 converts the answer in hours into minutes) which is only 50 minutes. HOWEVER, I have just pulled out a strip of LEDs that I have (type 3528 warm white) and is rated at 4.8 watts/metre and has 60 LEDs/ metre The strip offcut I have has 30 LEDs and is 50cm long With a DVM I measured it at 12 Volts and it draws about 150 mA and is VERY bright! I tried it on an EN22 alkaline, and because it is only 9 Volts the current dropped to about 5 mA ! On that basis an EN22 should be able to power 1 metre of 3528 strip for about 0.5 / .01 = 50 hours - which is more acceptable! The LEDs are somewhat dimmer on 9 volts but I think bright enough for your needs. I did try them on my variable supply and they stay lit at only 7 volts, though by then they are quite dim, but it does mean that the 9 volt battery would need to be pretty flat before the lights go completely out.
Your drawing shows actual wires between the cars. Why not just connect the battery and lights through wheel pickups. Let the rail transfer the energy between cars. That way if you ever decide to put the cars on a DC layout they might still work off track power.
good thought. it is a static display for this upcoming Xmas, however there are thoughts of a layout later. So I will consider that as an option. I do have a small pile of power supplies from old electronic stuff. I might even have an adjustable output supply so I could test various voltages and see how that affects brightness. I'm also checking with the lighting vendors to see what they suggest. Maybe there are lower wattage options.
that was an option I considered but I didn't want to mess with isolating wheels. I know of at least a couple ways to do what you are suggesting that I found on YT. I'll keep that option open if this approach doesn't work out. With the wheel pickups I'd need to wire up LEDs instead of using the LED strip (5050 strips are what I'm investigating now) and I just thought the LED strips were a cool idea so I'm seeing if I can make that work. The other concern with this method is that the lights would be on (DC) when the train is moving, but not at a station with no voltage to the rails.
wow! thanks, I feel progress is being made. I'm thinking 9 LED/car x 4 cars = 36 total so your numbers are within range. I'll check out 3528 strips! My thought is that the wires between cars would mimic hose connections.
