Modding Rainbow LED

It could be modified to work on 5V (just) but if by 5V headers you mean the mobo headers then no they just can not supply the power. It is designed to run directly from a molex from the PSU.

 

It just draws too many amps for headers to handle? How about using the HDD LED header to power the clock? My idea was, just so you know where all this is coming from, is rather then have the Night Rider bar graph to indicate HDD activity, have the speed of the color change indicate activity, with no activity being either steady or off.

 

Could you use this mod with the lighted fan strobe?

 

I was expecting this one ... In a word no. Not without extensive modding anyway.
TBH the RGB leds are not really bright enough for that application. They would work ok in low light but in normal lighting they would appear dim.

 

I did a similar mod sometime last year, but slightly differently. I had 3 separate 555's, each clocking 3 separate sine wave sources, which were buffered and powered each colour of the LED. It meant that the colour changes appeared much more random than this mod, but it was huge!

 

I tested quite a few different techniques including seperate waveform generators and phase shifters, but in the end I needed to keep the project simple and cheap to make it buildable by more peeps. (and you guys just think I throw this stuff together ).

 

Hi,
basically I was looking for an LED gadet for lighting my yet to be built acrylic mousepad. Your circuit looks nice but has the disadvantage of driving only one full color LED. Ok, I don't have a 2N3904 datasheet but the transisitor looks sturdy enough of driving more than one LED. I guess this one can drive up to ~100mA. That would be sufficient current for driving three LEDs instead of one.
Ok let's add another green LED +Resistor parallel to R1 and LED green. A problem is changing R6 because it is part of RC timing and base resistor to Q1. I have to decrease R6 in order to get higher current for the green LEDS. This means I have to increase C3 to have the same time constant as before. Hmm, I think this is nothing to be calculated, this is somthing that has to be soldered out...

The CD 4029 as IC2 has also some 'modding' potential. I think about adding dipswitches (mouse piano's) an the preset inputs J1 to J4. I have to find out how to connect the control inputs CI and PE. What is this all about? Let the circuit run free as before or stop it when the LEDs lit the color combination you like most for a constant light. In my opinion a important feature for a mousepad light device!

Now I'll search Google for a CD 4029 datasheet. I'll post again when I have more information and (hopefully) soldered out the problems. Thanks for the great site and for the forums with tons of ideas.

Greetings!

 

Uliger - welcome to the boards. Enjoy your stay.

You raise some interesting ideas. I had considered making the circuit cope with more leds but in the interests of economy and reducing complexity I decided against it.

When designing circuits for publication, I need to consider who will most likely want to build it so I try to keep the circuit as simple as possible. Obviously this means for going some features which probably only a small minority of people would use anyway.

The circuits are intended as a spring board for ideas and should be considered "building blocks".

I, and others, I am sure would be interested to see what mods you do to the circuit. Be sure to post your work.

 

I really know nowt about electronics as im only a GCSE student, but I do know the way of the 555 and transistors and stuff. Question is... my experience has never crossed a 4029N but I assume it is a counter and I do know the way of the 4017B counter could i use this IC instead of yours if I fiddle with the tracks, cos I can get hold of these easily trough school.

 

Nice work Macroman .

A few q's though.

Where did you get hold of that connector for the power? The socket and the plug, and is it the same as the one that conects to the motherboard for the LEDs etc? I don't want to run it off that, just need the connectors .

Do you make the PCBs yourself, or do you use somone elses equipment? If you do it yourself, can you recommend a good etch tank, or do you just make them in a tray?

Thanks

 

I've made one of those circuits they look great

but i have got one question, do you know any programs which can autorote the copper tracks, once u've designed the circuit on a program?

thanks

 

Eagle used and linked to in the article will do just that

 

Technical question...

Hiya,
first of all: great modding-idea; I really have to try this one out.
Just a little question: Would it be possible to replace the 555 and 4029 assembly with a simple 4060? It seems to have potential (see http://www.starshipmodeler.com/tech/cj_blink.htm ), but I'm quite new to this so I didn't want to try before checking with an expert...
Any comments?

 

Welcome to the boards, PontifexPrimus.

Looks workable to me.

In looking for the datasheet, there seems to be a 7060 without the internal oscillator, and also a 74HC7060 with it (http://www.philipslogic.com/products/hc/pdf/74hc4060.pdf).

I'd be careful to make sure you get the right one, but otherwise it looks like a great substitution to me.

(and solves a problem or two I've been wrestling with as well)

 

The 4060 is a useful chip. Unfortunately, just using a ripple counter to drive the RGB led will result at some point in all outputs being in the off state, causing no light from the led. This will break the continuous colour change. Of course if you want that effect then the 4060 does simplify the circuit.

 

Thanks for the fast response!

I think I'll try out both ways on my trusty breadboard and decide then...
Glad that it works at least in theory

Or I'll just cave in and hook it up to a uC, Atmel Tiny comes to mind - even though that's probably overkill

Thx again...

 

GigglesOfDoom, im assuming you could use the output from the HDD header to power the input on the circuit, maybe via a relay or similiar...

 

Not sure if this belongs in this thread or the night rider one

I have seen certain versions of the nightrider effect on sale from mod sites. And those leds fade in a smooth way like the rainbow thing with the capacitors. I think this looks really groovy cos its way smoother than your nightrider. Just wondering if you could use the capacitor-transistor thing on the nightrider to get a propper scan. Sorry if that is a bad description but I forgot the website with the pics

 

Ninja_182 - The trailing effect can be done with the transistor/ capacitor drive but is slightly more complicated due to the way the 3914 chip works. It was left off the final designs to maximise circuit simplicity so as to be buildable by most people, plus this is only eye candy and I considered most people wouldn't bother.

 

Excellent work, macroman. What type of LED are you using?

I am using a Nichia RGB LED that I would love to use your circuit to fade. However, the Nichia uses a common anode and grounds the red, green and blue respectivly. What would need to be done to retrofit your circuit to meet these requirements?

Thanks for any help.
Tom