Hi all.

Looking for a circuit that will let me cycle through 3 LED's, or the three colors of one RGB LED very quickly, one at a time.

Something like this first circuit, but faster and for 3 LED's instead of 2.

I'd like something that doesn't use an IC, ideally. I'm afraid that the chips will be too big to fit into the space in which I want to use them. (Inside a broomstick =^p) A simple circuit also seems easier to power.


Thanks for any tips!

~Jordan

 

I fit a similar LED dimmer (and the LED to boot) inside a pencil eraser tube, is that small enough?

Sorry could not find a direct link to the app note itself. This is a microcontroller based solution

 

Being non-microcontroller based was just because I've only used Arduino and the chips are pretty big.

Something that small would certainly work, but I am in over my head in some of this: I don't know what an "App" is, was expecting to see some kind of circuit diagram and don't know how I feel about "software solutions," which I keep reading about. I'm pretty sure the logic for what I want is very simple, I'm more concerned about how to build the dang thing.

Thanks for the post.


Can anyone answer OP's question?

 

I found this one http://www.bowdenshobbycircuits.info/page5.htm (second paragraph, but didn't check how well (or if) it works.

 

This is exactly what I was looking for. Not sure if it works either =^P

Going to learn how to read these circuit diagrams, and give it a shot.

Thanks!

Oh, before I forget: Is this something I could run off a couple of AA batteries?

 

You're going to need at least 5V for the blue LED, transistor junction and resistor drop (≈3.8V + ≈0.7V + ?). I'm no fan of 9V batteries but this would be a good place for one. In my simulation of Bowden's circuit (link below) I used 68µF capacitors and a 9V supply. It transitioned between colors at about 0.8Hz. The dropping resistors for the LEDs need to be around 390Ω (different for each LED).

http://www.falstad.com/circuit/#%24+1+0.0020+1.9265835257097934+50+9.0+50%0At+176+304+208+304+0+1+-0.9201162463964097+0.64071862965733+100.0%0At+320+288+352+288+0+1+0.5967000410686499+0.6617228138622422+100.0%0At+464+272+496+272+0+1+-7.260631430784951+-0.6916160865024285+100.0%0Ad+176+352+176+304+1+0.805904783%0Ad+320+336+320+288+1+0.805904783%0Ad+464+320+464+272+1+0.805904783%0Ar+464+272+400+272+0+100.0%0Ar+320+288+256+288+0+100.0%0Ar+176+304+112+304+0+100.0%0Ac+208+288+256+288+0+6.8E-5+0.7520883115326962%0Ac+352+272+400+272+0+6.8E-5+1.7901441996337%0Ac+496+256+544+256+0+6.8E-5+5.914927643389523%0Aw+208+320+208+352+0%0Aw+352+304+352+352+0%0Aw+320+336+320+352+0%0Aw+464+320+464+352+0%0Aw+496+288+496+352+0%0Aw+176+352+208+352+0%0Aw+208+352+320+352+0%0Aw+320+352+352+352+0%0Aw+352+352+464+352+0%0Aw+464+352+496+352+0%0Ag+352+352+352+368+0%0Aw+112+304+112+400+0%0Aw+112+400+544+400+0%0Aw+544+400+544+256+0%0Ar+496+256+496+192+0+330.0%0Ar+352+272+352+192+0+330.0%0Ar+208+288+208+192+0+390.0%0A162+208+144+208+192+1+1.9+1.0+0.0+0.0%0A162+352+144+352+192+1+3.3+0.0+1.0+0.0%0A162+496+144+496+192+1+3.3+0.0+0.0+1.0%0Ax+225+63+479+66+0+12+Kingbright+WP154A4SUREQBFZGW+RGB+LED%0Aw+208+144+352+144+0%0Aw+352+144+496+144+0%0AR+352+144+352+112+0+0+40.0+9.0+0.0+0.0+0.5%0Ax+255+40+437+44+0+16+1+of+3+Discrete+Sequencer%0A

 

LEDs, 555s, Flashers, and Light Chasers

Chapter 11 - Making Patterns

 

A tiny pic chip is not big & can adjust speed with sw.

 

May be you can use a single IC (which contains counter+decoder) set counter to count 0 1 2 0 1 2 0 1 2 ( other IC may be for clock). other wise you need multiple caps, R, transistors. may be single or two ICs will give more compact sol.

I like PIC sol also it is also available as flat quad package v v compact but u need PCB for using it.