# LED Lantern Flicker Circuit



## shaunathan

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

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

_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

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

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

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

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


----------



## sgtdrpepper

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

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

*Multiple LEDs by this circuit?*

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.


----------



## Otaku

Nice! Building the circuit looks pretty straightforward, and I'll bet the parts are cheap at All Electronics. Are you able to post a how-to?


----------



## heresjohnny

As I build the circuits I would like to post results, and to have some clips of the circuits in action on my web page (or in this forumif I can post video). Does anyone know what to do about the 'Y1 96kHz' component? I think that is the quartz crystal, but there is not enough information for me to find and order a part (the crystals I find have 2 leads). I also don't know how important the frequency is. Any help would be appreciated!


----------



## Otaku

I'll see if I can scare up a spec sheet online for the oscillator (crystal) and talk to one of the EE's at work. I'll let you know what I find out.


----------



## heresjohnny

Thanks otaku. I know a bunch of software guys, but no EE's. I think(?) the circuit takes a signal from the crystal and drives the counters, with the various outputs of the counters providing the signals at different frequencies and patterns. I am also not sure about the LM2940, does this circuit need a 1A voltage regulator?

Any info would be great! This is also a good way to build up posts to 30!


----------



## Otaku

I haven't been able to find a spec sheet on that crystal yet, but am still looking. I'll check on the LM2940 as well. What are the two IC's on the board? Ripple timers or counters? I see a lot of diodes on the board; I assume this is to prevent overdriving the LED(s). I was also wondering if this circuit could be used to power incandescent lamps, and what is the max voltage that can be used. I can see many possibilities for lighting effects with this circuit, and I've always been envious of the Disney flicker effects. I talked to Disney engineering once about the circuits used in the pumpkins behind the Haunted Mansion (during the NBC decoration time) and they gave me the name of a company that does stage lighting effects. The price for a single flicker circuit was $35, but you could run a number of 110 volt lights with it.


----------



## heresjohnny

The 4060's are counters. The LM2940 is a 1A low dropout voltage regulator http://www.national.com/pf/LM/LM2940.html, ok I think I know what all of that means. I was wondering if the .5 amp regulators were good enough and easier to find, I think LEDs only draw current in the mA range.

I have seen a circuit or 2 for incandescent flicker, but I didn't save them, sorry. I saw the reference to spookyblue you mentioned at the halloween forum, based on the video there a collection of blinking LEDs may well give me what I'm looking for.


----------



## Otaku

Yes, the Spookyblue flashing LED circuits are a good effect. I made two of them for a pair of smoldering urns. I covered the LEDs with a bit of stretchy web to diffuse the light. They're really cheap to make, too. For the lantern that my Reaper is holding, I used a BLF circuit that I got from Haunt Master Products. It has a good flicker effect and is adjustable, but I think it works best if the light source is diffused. It kind of looks like a scaled-down fluorescent-starter flicker.


----------



## ScareFX

Quite a bit OT here, but did you folks see on RocketBoom what those wacky New Yorkers are doing with their LEDs?

http://www.graffitiresearchlab.com/


----------



## heresjohnny

I wouldn't mind finding some of those lying around, free LEDs! Hey Otaku, did you notice a difference between the blinking LEDs from Spookyblue, and the BLF circuit? Was one better than the other?

I'm going to have to do one more post this morning, that will put me at the half-way mark to $20 prop eligibility.


----------



## heresjohnny

Otaku, have you seen this flicker circuit for incandescent (i think) lights? Thought this might be what you were asking for earlier. http://www.phantasmechanics.com/alf.html


----------



## Otaku

The Spookyblue LED flicker fire circuit uses multiple flashing and steady LEDs and so it is a larger package. The BLF can use a single lamp with varying rate and brightness. It actually uses 3 variable speed flicker circuits, and the brightness changes happen when two or more of them synchronize. I would say that the BLF works better if you need a point-source flicker effect such as a lantern, and the Spookyblue design works best for lighting the larger areas. Both look more realistic if the light source is viewed indirectly, using either reflection or diffusion. Another difference is that the Spookyblue "blob" never appears to be completely "off". With a BLF there can be instances where there is no light, but we're typically talking about microseconds. You may be able to set one of the three BLF circuits to "constant on" and eliminate this. I'll try it with mine and let you know.


----------



## Otaku

Yes, I checked out the circuits on Doug's site. I built a couple of the fluorescent starter circuits and they work nicely for dim, flickering outdoor lighting. I usually use 7.5 watt bulbs with them. The circuit I ended up making was the same as the one shown on the Monster List. It's called "Fluorescent Starter Flicker Thingy" or something similar. I'd like to build a Flicker Pilot sometime, though. I think it would have more of the "Pirates of the Caribbean" look (the lanterns at the boarding area) where the lights dim and brighten, but never really go out.


----------



## heresjohnny

I used fluorescent starters last year, was wondering if you had any experience with the ALF circuit. I'm still waiting for the parts to show up, I ordered blinking LEDs for the spookyblue effect and the schmidt trigger and stuff to build










I am spending way too much time on this, but it will be good to have a comprehensive analysis of all the techniques.


----------



## Otaku

Too much time?? Maybe, but it's so much fun! No, I haven't built an ALF circuit (yet) but will likely make some Flicker Pilots later this year. The F-P sounds like it may need a bit of tweaking but looks easy and cheap to make. If you're interested, I could try to find those circuits that Disney uses in their pumpkins. As I mentioned, they sold for about $35 each, though.


----------



## heresjohnny

I don't know if I want to spend $35 for a flicker circuit, but it would be nice knowing how Disney does things!


----------



## heresjohnny

My parts finally arrived, so this weekend I'm going to try the schmidt trigger circuit and the spookyblue flicker. I finally found the LED tea lights at Walgreens of all places.


----------



## Otaku

I emailed the Disney Guest Services folks. The auto-reply says it may take a few weeks to get the info. We'll see. I agree that $35 is a lot for a single flicker circuit, but it sure was a nice effect.


----------



## heresjohnny

So far have 3 flickers to capture on video, the LED tea light, the spookyblue technique of clustering flashing LEDs, and a real candle (just to see if I can fool anyone:devil: ). The schmitt trigger circuit is giving me a hard time, but the creator responded to my questions and I found out I had a couple of bad capacitor values. The thing I like about the shmitt trigger circuit is that you can supposedly vary the effect from a flicker to shimmer by adjusting the sampling frequency. Looking forward to seeing it in action.


----------



## Otaku

About the LED tea lights - you mentioned that the effect is good, but rather dim. I wonder how easy it would be to install a brighter LED and if it would affect the flicker. The lights are probably sealed/potted and may be hard to open, but for a couple of bucks each I think I'll give it a try. I'll let you know what I find.


----------



## heresjohnny

I have more parts ordered for the campfire flicker circuit, and correct parts for the schmidt trigger circuit. As soon as I get some circuits working I will start posting video clips of the different ones.


----------



## heresjohnny

Quick update. Got the wrong schmidt trigger, and the order for the parts based on the 555 timer got screwed up, so I'm still waiting..... Did find out the thing in shaunathan's circuit is a crystal oscillator, but I can't find a 96k one. I wonder if the way it is hooked up means the frequency matters (EN, or enable is not connected). Anybody know?


----------



## heresjohnny

Got the schmidt trigger circuit working, very nice! The correct 555 is on the way, I am gonna start getting the video pulled together. Another week or so.


----------



## mrklaw

heresjohnny, could you post the part numbers that you used to order the parts for the schmidt trigger circuit? I think I'd like to try building one and don't want to fall in the same traps you did.


----------



## heresjohnny

mrklaw, I should have all of my information posted Friday, including videoclips of the different flickers and parts list/prices. If you need the info before then PM me and I will get it to you tonight.



mrklaw said:


> heresjohnny, could you post the part numbers that you used to order the parts for the schmidt trigger circuit? I think I'd like to try building one and don't want to fall in the same traps you did.


----------



## mrklaw

I can wait. Thanks!


----------



## heresjohnny

OK, I have the schmidt trigger and the twisted ring counter circuit working (thanks Engineer!). It is a good flicker effect, but distinctly different from the schmidt trigger circuit. It will be interesting to see which one is more popular. 

TBH, both circuits are too dim to be used for indirect lighting using normal LEDS. Last night I tried to video the various flickers inside a plastic carved pumpkin I have, and it was to dim to be an effective prop, much less video. I think both circuits could use a single LED as a point source in a lightly diffused container, it would not provide much light but would serve as a point source. Tonight I will try some ultra bright LEDs I got for spot lights as an indirect source. I will also try to capture the flickers as point sources. Since I now have a domain (johnnyspage), I have room to host all of this. Stay tuned!


----------



## Frighteners Entertainment

Nice job on the site!!

Jeff


----------



## DeathTouch

Hey heresJohnny. How did you do smoke/cloud effect when you show like the projects page and etc? The image on the top that says projects that has the cloud behind it.


----------



## heresjohnny

DeathTouch, I am lazy and use FrontPage for the site, and I created a theme for Halloween. FrontPage lets you select a gif for the Banner, over which it place the page title if you include it in the navigation (which will not make sense if you don't use FrontPage). I assume it is using CSS.

The LED Flicker videos are posted. I will get the parts list and price posted later this weekend. My favorite is the schmidt trigger circuit, I like it better than the real candle! Check it out at http://www.johnnyspage.com/LED%20Flicker.htm


----------



## Frighteners Entertainment

DeathTouch said:


> Hey heresJohnny. How did you do smoke/cloud effect when you show like the projects page and etc? The image on the top that says projects that has the cloud behind it.


DT, it's called a rollover image.

If you google it, you may get how it works.

Jeff


----------



## .id.

heresjohnny said:


> Did find out the thing in shaunathan's circuit is a crystal oscillator, but I can't find a 96k one. I wonder if the way it is hooked up means the frequency matters (EN, or enable is not connected). Anybody know?


The other option is to build a RC clock or a normal crystal clock for the first 4060 chip. (Page 3 of http://www.fairchildsemi.com/ds/CD%2FCD4060BC.pdf shows how to do this.)
Hope this helps!


----------



## Koumajutsu

OK, going on year 2, and we have version 2 of our version of this prop in the works. thins time with an etched PCB. We may have 2 left over (PCBs only, not entire lanterns. and likely with all the parts installed) and we may be looking to unload them to recoup some of our costs. Shaunathan or I will post pics and vid as soon as we take some


----------



## Koumajutsu

heresjohnny said:


> Quick update. Got the wrong schmidt trigger, and the order for the parts based on the 555 timer got screwed up, so I'm still waiting..... Did find out the thing in shaunathan's circuit is a crystal oscillator, but I can't find a 96k one. I wonder if the way it is hooked up means the frequency matters (EN, or enable is not connected). Anybody know?


the part we used is marked as a LM2000 series crystal oscillator. I had them handy and i like the stability and ease of use


----------

