Need EE's, LED Dimmer circuit

UnaClocker · 11-10-2002, 04:03 AM

Ok.. I have this really cool idea for LED's, but I need a good way to auto dim them. I found a couple cool dimmer circuits on the web, but they all depend on someone twisting a pot to raise and lower the brightness. I want one that will make an array of LEDs slowly fade off and slowly fade back on, forever.

I'm stumped on how I'm going to do it, I was thinking I'd just build a circuit that simulates a pot for the voltage regulators that would dim and brighten the LEDs, but I haven't had any luck finding such a circuit anywhere. Anyone know how I can pull this off? Oh, and if I can vary the speed of the dimming/brightening, that'd be a huge plus.

Thanks.

MadDogMe · 11-10-2002, 04:55 AM

Heh!, I've got a fuucked dimmer switch for the 240 mains light in my room does the very thing. so it has to be possible...
It's infrared though, has one of those 'touch pads' instead of a switch, that's what's giving the problem I think...

bigben2k · 11-10-2002, 07:47 AM

Una: what you're looking for, is a wave generator that outputs a triangular signal.

dax · 11-10-2002, 08:16 AM

would be pretty easy... i encountered a few schematics for something like that on the net a few months ago... don't know where i found them though... if i'm not mistaken it can be done with a 555 timer IC and some basic components.

UnaClocker · 11-10-2002, 01:03 PM

I found the circuit for dimming it with a 555.. But it needs someone to be manually turning a potentiometer..

I'll do some searching for that triangular wave generator and see what I find.

nexxo · 11-10-2002, 02:49 PM

Unaclocker: there are two circuits that may be of interest to you:

RED Free Circuit Designs has a LED pulser which does what you describe. On that site they also do a variation where two LEDs pulse alternately. Speed on both circuits can be manipulated.

Another interesting one is on
Bit-Tech.Net, and involves an RGB LED smoothly cycling through all the colours of the spectrum. Neat!

UnaClocker · 11-10-2002, 05:52 PM

Quote:

Originally posted by nexxo
Unaclocker: there are two circuits that may be of interest to you:

RED Free Circuit Designs has a LED pulser which does what you describe. On that site they also do a variation where two LEDs pulse alternately. Speed on both circuits can be manipulated.

Bingo! I do believe that will do what I need. Thank you!

11-10-2002, 04:03 AM	#1
UnaClocker Cooling Savant Join Date: Apr 2000 Location: Bremerton, WA Posts: 514	Need EE's, LED Dimmer circuit Ok.. I have this really cool idea for LED's, but I need a good way to auto dim them. I found a couple cool dimmer circuits on the web, but they all depend on someone twisting a pot to raise and lower the brightness. I want one that will make an array of LEDs slowly fade off and slowly fade back on, forever. I'm stumped on how I'm going to do it, I was thinking I'd just build a circuit that simulates a pot for the voltage regulators that would dim and brighten the LEDs, but I haven't had any luck finding such a circuit anywhere. Anyone know how I can pull this off? Oh, and if I can vary the speed of the dimming/brightening, that'd be a huge plus. Thanks. __________________ The UnaClocker Watercooler Extraordinaire! Overclock till it goes BOOM!

11-10-2002, 07:47 AM	#3
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Una: what you're looking for, is a wave generator that outputs a triangular signal. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

11-10-2002, 01:03 PM	#5
UnaClocker Cooling Savant Join Date: Apr 2000 Location: Bremerton, WA Posts: 514	I found the circuit for dimming it with a 555.. But it needs someone to be manually turning a potentiometer.. I'll do some searching for that triangular wave generator and see what I find. __________________ The UnaClocker Watercooler Extraordinaire! Overclock till it goes BOOM!

11-10-2002, 02:49 PM	#6
nexxo Cooling Savant Join Date: Jul 2002 Location: Brimingham, UK Posts: 385	Unaclocker: there are two circuits that may be of interest to you: RED Free Circuit Designs has a LED pulser which does what you describe. On that site they also do a variation where two LEDs pulse alternately. Speed on both circuits can be manipulated. Another interesting one is on Bit-Tech.Net, and involves an RGB LED smoothly cycling through all the colours of the spectrum. Neat! __________________ "There is a thin line between magic and madness"

11-10-2002, 04:55 AM	#2
MadDogMe Thermophile Join Date: Aug 2002 Location: Just shut up ;) ... Posts: 1,068	Heh!, I've got a fuucked dimmer switch for the 240 mains light in my room does the very thing. so it has to be possible... It's infrared though, has one of those 'touch pads' instead of a switch, that's what's giving the problem I think...

11-10-2002, 08:16 AM	#4
dax Cooling Neophyte Join Date: Nov 2001 Location: Ghent, Belgium Posts: 83	would be pretty easy... i encountered a few schematics for something like that on the net a few months ago... don't know where i found them though... if i'm not mistaken it can be done with a 555 timer IC and some basic components.

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