[heresjohnny]

I got a lot of real good feedback on the LED flicker poll, and I have applied that feedback to develop a new flicker that I think most will like. Please check it out at http://johnnyspage.com/LED%20Flicker.htm, click the jack o lantern titled 'mystery flicker' and let me know what you think.

Thanx!

 

[Otaku]

I like the Mystery Flicker. It's similar to the LED tea light, but significantly brighter. It also seems to have a dim-to-bright cycle. I gotta go get some of the tea lights and see if I can change the LEDs. Looks good, heresjohnny!

 

[Zombie-F]

Me likey! Very good.

 

[Dr Morbius]

Now..would those work in a lantern hack?

 

[heresjohnny]

I think it will work very nicely in a lantern. I have several small ones from Big Lots waiting for the time...

The mystery flicker is the schmitt trigger circuit (flicker 1 by snovtill) with a 15k resistor replacing the 390k resistor. Per the author of the circuit, I replaced the 390k with a potentiometer and adjusted it until I liked the effect, with the result being 15k. I like this circuit because it is easy to build for a circuit, and the components cost less than $2.00 (I am so cheap!). I plan on laying out a circuit board for this and making some in quantity, will post when I'm done.

 

[gmacted]

Very Nice!!!!! I would have never guessed it was an LED.

 

[mrklaw]

When I looked for 4585 schmidt triggers on the jameco website, I got the following list:

Passive Components:Capacitors:Tantalum  	 	1  	View List
Passive Components:Capacitors:Ceramic, Disc 	 	1 	View List
Passive Components:Frequency Control:Crystals 	 	1 	View List
Interconnects:D-Sub Connectors:Hoods 	 	 	1 	View List
ICs & Semiconductors:Logic, CMOS:74AHC Series 	 	2 	View List
Test, Tools & Supplies:Tools:Hand Tools, Strippers 	2 	View List
Wire & Cable:Management Products:Clips & Clamps 	1 	View List
ICs & Semiconductors:Logic, CMOS:74HCT Series 	 	1 	View List
Interconnects:Terminals:Solderless 	 	 	8 	View List
Electromechanical:Hardware:Tape & Mastics 	 	1 	View List
ICs & Semiconductors:Logic, CMOS:74HC Series 	 	2 	View List
ICs & Semiconductors:Logic, TTL:74ALS Series 	 	2 	View List

Is one of these the right component? None of the ones I looked at said 4585 or schmidt trigger when I clicked on them.

 

[heresjohnny]

Damn, there is an error in my part list, sorry bout that. The number is 4584, and the jameco part number is 13768, try that. I will fix the page as soon as I get home tonight, thanks for catching that!

 

[gmacted]

here'sjohnny,

I just had an idea for your flicker circuit. This could be used in "Zombie-Fs" unearthed coffin. You would just have to replace the red LEDs with green ones. I may need to add a few more LEDs however to get the right brightness. How much current can the schmidt triggers sink?

gmacted

 

[Otaku]

heresjohnny,
I picked up one of the LED tea lights at Walgreen's and yes, it is hackable. I did this one the hard way, by taking the whole thing apart to get to the LED. Lots of de-soldering. The easiest way to replace the LED is to cut away some of the molded silicone from the base of the LED, cut the exposed leads, and solder the new LED directly to the leads. Verify the polarity so you only have to do it once. I plan to also wire in a 2AA battery holder to extend the battery life.

 

[Otaku]

Update on the tea lights - the LED can be easily replaced with a brighter one. but it drains those little batteries fast. The circuit will handle a 4.5-5VDC input, so I wired a 3AA pack to the terminals and the LED is now VERY bright. If you use a narrow beam LED just bend the leads to the side and stick on a small diffuser.

 

[heresjohnny]

otaku, thanks for the info. I will have to try this hack myself and add the results to my LED flicker page. Do you still get a nice flicker with the brighter LED?

 

[Otaku]

Yes, the flicker rate and voltage variability seem to be unaffected by the higher input voltage.

 

[heresjohnny]

I was messing around this weekend with a cheap way to build one of these circuits. I tried using card stock, marking the holes for the 2 ICs, inserting the ICs, then the jumper wires and other components, and soldering the whole thing together. Worked like a charm! I wouldn't want to use this technique for anything critical, or high current, but for a 20 mA LED flicker circuit it should be okay. This is the snovotill circuit, nice small package, runs off a 9 volt battery.

Could put this in a small jack o lantern and get this effect

http://johnnyspage.com/video/mysteryFlick.wmv

 

[NecroBones]

Looks great! I may need to start building some. Cheap is always good. Of course, laziness often sets in and I build nothing. Heh.

Perhaps I missed it, but did you have a circuit diagram for it?

 

[heresjohnny]

NecroBones I have a page devoted to flicker circuits here http://johnnyspage.com/LED%20Flicker.htm
including the circuit built in the picture (snovotill's firelight flicker, with an 18k resistor instead of a 390k).

 

[Dr Morbius]

I'm gonna have to build some of those. Nice work HJ!!

 

[NecroBones]

Yeah, I was looking there and only saw the parts list. I didn't realize there was a link above the jack-o-lanterns for the diagram.

 

[Otaku]

Hey, HJ, let me know how those big LEDs work in a flicker circuit. I may want to get some for the tea lights.

 

[heresjohnny]

Hey, HJ, let me know how those big LEDs work in a flicker circuit. I may want to get some for the tea lights.

Well I finally got around to trying the 10mm 60,000mcd LEDs in the flicker circtuit and they work great! By far the brightest LED flicker I have seen yet. Here is the video http://www.johnnyspage.com/video/flicker10.wmv, details at http://www.johnnyspage.com/LED%20Flicker.htm. The difference can really be noticed if you compare the 2 snovtil circuits, the one with the 60,000mcd shows the edges around the mouth, nose and eyes very clearly compared to the others.