LED Lantern Flicker Circuit

shaunathan · #1 09-26-2005

Ok, as promised, here is an update on the flicker switch. The breadboard version is done and we've begun construction. (Schematic to follow in another post trying to make it look nice and easy to follow.)

Now keep in mind my friend invented this, and I'm a computer science major, not an electronics major, so I'll do my best to explain what it does.

The LED on the breadboard was just a test LED so he could check if the flicker circuit was working properly. The dipswitches let you partially control the behavior of the flicker. The LED never actually goes out and is dimmed per switch, each switch is a different random pattern generated by the quartz crystal thing-a-ma-bob in the silver boxy component (oh yeah I'm so technical it hurts) Some of these parts you see here are military grade components. DON'T ASK. But you can find their civilian counterparts at a good mom-and-pop electronics store (Radio Shack is over-rated, go support the people barely makin' rent.) Those things that look like resisters, but are a different color (forget what their called) keep the randomness from making the LED brighter than it should. so it only has normal on, and dimmer. If you set all the dipswitches down, you get constant on due to these components.

Here's the back:

nothing exciting there really.

shaunathan · #2 09-26-2005

Now here's where we get into the good part (my idea) We hid the on/off switch in the kerosine fuel cap! We used a push button switch, and mounted it inside the cap itself, it's just two peices of steel and crimped together like a bottle cap, so we took it appart and used the washers and nut included with the screw to attach it to the inside of the cap, then we glued the top of the cap to the button top.

We plan to hot-glue the bottom of the breadboard once we hook it up to the permenant LED's so it doesn't short itself making contact with the lantern. (cheaper than epoxy,same result.) at this point, something like electrical tape will keep the board in place as well as the battery. Since we cut the entire bottom out of the fuel tank:

we think we'll just mount a few magnets and that'll keep the base on well enough. You should really see the flicker circuit in action, it works just as good as anything I've seen at disneyland if not better, and is VERY convincing as a burning flame source.

Next step is to fog up the glass, probably with glas etching. Then we can see if the LEDs we bought are gonna work. We're using 2 reds and a green (red + green at the same time will look amber.)

shaunathan · #3 09-26-2005

NOTE: That's my friend who designed the flicker switch in the picture with the lantern doing the cutting. All these pics were taken with my camera phone, so sorry about picture quality, also, multiple posts due to some kind of crazy picture limit per post.

shaunathan · #4 09-30-2005

UPDATE: Well, remember how on zombie-f's how-to he said "I should have got the etching solution you dip glass into" ?? well it comes in 16 ounce bottles for 35 dollars (or so) each!! lucky I was armed with my 40% off one item coupon for michaels, saved 15 bucks. However, if you buy the standard wal-mart 4 dollar lantern, the glass appears to take more than 16 ounces, so we've come up with a trick for this, and I hope it works.

we're gonna plastic wrap and rubber band the bottom, and fill the glass with etching solution (which will only go half way) after 5 to 10 min, we empty, flip it, plastic wrap the other end, and repeat. this etches the inside rather than the out (Which takes less liquid) and solves the problem of what to pour the solution in because according to the directions this stuff eats just about everything.

Zombie-F · #5 09-30-2005

For my more recent ones I used Krylons Glass Frosting spray paint... $4 a can. You can easily frost 4 or more lanterns with one can. I really need to update the how-to.

shaunathan · #6 09-30-2005

now he tells me!!! well I ahven't opened anything that cuoldn't be put back in the box, maybe I can get a refund....

EDIT: took it back, got my 23 bucks and bought the $3.74 can of glass frosting at Lowes. They don't carry Krylon, but this stuff was under your 4 dollar mark, working on the lantern more tomorrow, so more pictures coming. and we'll write up that how-to so you can append it to yours zombie.

shaunathan · #7 10-03-2005

Here is the Schmatic for the Flicker switch:
http://www.gam3r.com/pics/flicker.gif

sgtdrpepper · #8 10-03-2005

Would love to see some action shots of the circuit. Looks like a fairly easy to build circuit, thanks for sharing with us.

Sgt

heresjohnny · #9 02-15-2006

Hey everybody, I am new to this forum, and made my first haunted house this past halloween. I would like to find a good LED candle flicker technique, either buying and hacking the LED tea candles or building a circuit. So any of you have any recommendations from past experience? I have collected several circuits and circuit links on my web page if you are interested (including this one, thanks shaunathan).

I'm really looking forward to building haunted house 2006, building lots of props and sharing ideas.

Thanks,
heresjohnny
http://home.cfl.rr.com/myhalloweenpage

heresjohnny · #10 02-16-2006

I am looking at the circuit (I know a little about electronics), and I was wondering if you could drive more than one LED? For example if you could use half the outputs for one LED and half for the other, or maybe even have multiple LEDs sharing different groups of outputs. I guess it depends on how many outputs you have to combine to get a decent flicker, and how much power each output can handle. My thought is that if you could drive multiple LEDs to different random patterns from this circuit, a single circuit could drive a candelabra or chandelier.