Back in December 2011, I added some flickering lanterns to the Bear Country tunnel. I was able to achieve this using some cheap tea-light LED candles from Target and wired them onto my own circuit. This subtle feature was a great addition and added another layer of realism and effects to the layout.
With Rainbow Ridge, I knew there would be a LOT of lanterns to add as well as all the buildings having interior lighting, plus the load/unload area lighting.
I loved the Bear Country lanterns so much I wanted to add them to Rainbow Ridge. My only issue with them is the color; much too yellow to be totally convincing. To combat this, I decided to go with a mix; yellow flickering LED's and a majority of warm-white LED's.
In an ideal world, having all the lights meant to be candles or lanterns should flicker in Rainbow Ridge. I tried a few set-ups trying to get the yellow flicker LED's to affect the warm-white ones for similar flicker effect. Nothing worked. I would plan to have the flickering yellow LED's and the warm-white LED's constant.
It wasn't until I discovered this article I found a solution. Rather than trying to tie the flicker LED in-line with another or other LED's I found a way to have it be a micro-controller; have the flicker LED control another set of lights. The best way to do this was to use an electronic component I hadn't used before: transistor.
I spent about 3 days prototyping, testing and developing a circuit that both looked good and worked efficiently (as in no hot components!). What I came up with was rather surprising for myself.
I posted a video over on the Facebook page, much to everyone's intrigue of the circuit above
Instead of using warm-white LED's I ended up going back and using my old 12V incandescent grain-of-wheat lights, which I haven't used since I started converting over to all-LED lighting last December.
The reason for this being is not only is the color more realistic, but the actual flicker looks better; the incandescent bulb "smoothes" out the rather jerky flicker from the LED and looks much more like a real candle/lantern. While LED's have brought a whole new level to the layout, in terms of color, power efficiency, and vibrance, I guess Rainbow Ridge will have to make an exception here.
To explain how I did this, I drew up a schematic of the circuit. I'll also try and explain it as easily as I can to those not as electronic savvy.
The entire circuit--the "controller" flicker LED and the 12v incandescent lights-- are all on the same power source. The 1kΩ resistor brings down the current for the flicker LED and the 10Ω reistor also brings down the current, but to the transistor. The power coming from the LED connects to the base of the transistor, allowing current to flow from the 10Ω reistor, to the 12V Inc./Incandescent light. The transistor is a standard 2N222A I picked up in an assortment pack from Radio Shack for a couple bucks.
The reistor with the question mark is an override resistor; this can be any value; the lesser the value, the more "un-modified" current goes to the 12V light, making it brighter, but also flicker less. After the initial test video above and looking at Disneyland's own flickering lights, I determined a proper balance of subtleness and noticeability using a 47Ω reistor in this spot.
This circuit only has capacity for 3 incandescent bulbs; any more and I'd have to beef up the components to prevent overheating (and more maintenance). This isn't a problem; having every light flicker on the same frequency wouldn't realistic, right? So, to fill out Rainbow Ridge, a number of these circuits, or modules, will be put together for a variety of random flickering lights.
Here's a module put together in practice:
The top red wire is coming from the (+) 9V source and the bottom red wire goes the incandescent light. The other lead for the incandescent goes to the (-) ground. In the photo above this one, you can see the next module marked out next to the complete one, to give you an idea of how this was wired together in my usual 'amateur circuit board' approach, aka nails on a piece of wood.
Here's the finished "Flicker board" with 8 flicker modules, with a capacity to power 24 lights in Rainbow Ridge.
As the lighting progressed, some more ground way laid down in the Casa de Fritos area. The tricky part here is the sloping ground to create the different leveled sections. This is also where some wiring will run, so the lighting project above had to be done first!