[FearingtonHouse]

I've got a skull mounted on each of two large columns that flank my cemetery gate. I want to put red LEDs in their eyes and would like them to fade slowly (very slowly) on and off - maybe even with a few seconds between completely off and starting to fade back on. And, it would be great if they would do this in unison. So, I've been searching for something (cheap) to do this. At $7, this is the closest thing that I could find. I would string this between the columns and just tape over all of the unneeded LEDs & use only the 4 that I need. Any thoughts on this? Is there a better way to do this that doesn't cost more than maybe $20 to run both sides?

http://www.amazon.com/NexScene-String-Wedding-Christmas-Holiday/dp/B00JC2BGGE/

 

[CreepyCreations]

Is this sort of what you were going for?

 

[Rabbit101]

I've used the Bill Bowden circuit many times and it works great, in my Monster In A Box I have 4 sets of ping pong balls that glow at different times and look as if critters are moving around in the box.
Heres the schematic

Fading Eyes LED project

You can do a Bill Bowden search and find he has many schematics and ideas to chose from

 

[annamarykahn]

thx for the info r101!

i googled and came up with this link to bill's site => http://www.bowdenshobbycircuits.info/

amk

 

[FearingtonHouse]

thanks, folks. So is there a lazy man's way that does not involve a soldering iron, muriatic acid or a volt/ohm meter.

 

[dirtTroll]

Yup:
http://www.cowlacious.com/categories/Lights/Universal-Fading-Eyes-Deluxe/

That is, when they have them in stock....

 

[FearingtonHouse]

Yup:
http://www.cowlacious.com/categories/Lights/Universal-Fading-Eyes-Deluxe/

That is, when they have them in stock....

Yes, thanks for this. I had contacted them and they said they'll have more by the middle of this month. That said, is there a way to make one of these work for 4 LEDs?...so the two sets of eyes fade in unison? Hmmm...do they make these units themselves? Should I ask if they can do one for 4 LEDs?

 

[Col. Fryght]

Yup:
http://www.cowlacious.com/categories/Lights/Universal-Fading-Eyes-Deluxe/

That is, when they have them in stock....

Never knew about this site. How is the customer experience?

 

[dirtTroll]

Yes, they make the boards themselves. You can talk with them and see what they can do. Customer service is ok... I had trouble contacting them last week and trouble with an order (more on information about the order) but I found out they had been in the process of a move... so... give them a bit of slack there. I have their cave eyes I have been using for years now... work great and no complaints

 

[FearingtonHouse]

I sent them an email asking about doing this for 4 LEDs. Will update as I hear more information...

 

[CreepyCreations]

It should be a simple matter of adding two more LEDs in series and dropping the resistor value, assuming the supply voltage is enough to run them all.

 

[FearingtonHouse]

Thanks, CreepyCreations. My Cowlacious LED fader arrived today (yay!!) and I was playing around and I think it only worked when both LEDs were plugged in. Is it possible that they wired the two LEDs in series on the board already? The resistor is built into the board and I don't really want to modify it, but that may not be a problem for my application, since I'm looking for a mild effect...with dim to moderate LED light output. According to an online LED resistor calculator ( http://led.linear1.org/led.wiz ), two red LEDs (@9vdc) would require a 270 Ohm resistor, but 4 LEDs only need 56 Ohms...so I've clearly got more resistance than I need. Since I don't need killer light output, wouldn't this be ok or could this damage the board in some way? (I sent them an email asking about this, but never heard back.) Thanks for any advice!

 

[mickkell]

Yes, they make the boards themselves. You can talk with them and see what they can do. Customer service is ok... I had trouble contacting them last week and trouble with an order (more on information about the order) but I found out they had been in the process of a move... so... give them a bit of slack there. I have their cave eyes I have been using for years now... work great and no complaints

Not sure about that,they told me they had 1000 boards (fading eyes)coming in from China.And extra fuel costs jumped the price way up,IMO.

 

[CreepyCreations]

Fearington... those resistor values sound right for both 2 and 4 LEDs. It sounds like they wired the LEDs in series on the board. Especially with the given resistor value, that's the only way they likely COULD have been wired. If you are trying to use more than the 2 LEDs, you will probably have to replace the resistor with a lower value. If you leave the 270 ohm resistor in place, you will only be providing roughly one quarter of the current needed, so the LEDs will not be very bright at all. Quite dim, in fact, I think.

 

[FearingtonHouse]

You were so right, CreepyCreations! When I inserted an additional LED into the circuit in series, the LEDs were barely putting out any light.

And, there is a fairly important (IMO) caveat with these things. When you dial in the duration of the cycle and the amount of time that the LEDs stay on versus off...just when you've got it all perfect...if you toggle power, these cycle times change. Then, you have to play with it again to reconfigure. Although there are instructions with it (and I'm a computer guy), I've still had a difficult time figuring out exactly how to get these to cycle the way that I want. They seem to be more conducive to short cycles with quick on/off. And, just leave the power connected. Forever!

 

[budduke]

Yes, thanks for this. I had contacted them and they said they'll have more by the middle of this month. That said, is there a way to make one of these work for 4 LEDs?...so the two sets of eyes fade in unison? Hmmm...do they make these units themselves? Should I ask if they can do one for 4 LEDs?

I bought them a few years back. It looks like the same thing. I had 4 bucky skeletons with the fading led eyes that I put in them and what I did was cut the 9volt connector off and ran wire between all of them in parallel and then attached the end to a 9 volt power adapter and when I first plugged it in, ALL the skeletons are in unison when fading on/off. It is a very cool effect that I was not expecting and has been running for 4 years now. I used ziplock bags to put the boards in and taped where the wires come out real good and it has gone though allot of bad weather in my area every year just fine. Not sure if the effect was accidental and I got lucky but I love it.