Sound to Light - Colour Organ

Thread Starter

edwardholmes91

Joined Feb 25, 2013
210
Hello,

In 2008, I designed and built a simple light box for use at party's and discos. It consists of a 9 x 8 array of E10 MES bulb holders and 12V LEDs, wired in 3 series circuits. The three channels are fed from bridge rectifiers, although the LEDs state they can operate of either AC or DC without any problems. To control the three channels, I used an old Christmas lights sequencer. This worked fine for quite some time and then stopped working, so I replaced it with another of the same controllers, but the time has come to give it an upgrade... sound to light.

When I've searched online for sound to light circuits, I've found several options including:
So I have a few questions...
  1. Which do you think would be most suitable? They all have three channels, but are of varying complexity.
  2. As far as I can make out, they all require a wired input and ideally I'd like to use a built in microphone to control it. I did think about using a piezo element, but after a little research, I realised that they are ideally suited as a contact microphone, e.g. for an acoustic guitar pickup.
  3. How would I be able to adapt any of the circuits above to switch mains? I was originally thinking along the lines of a driver and a relay, but decided this wouldn't be suitable because it would likely wear out after little use. Other ideas included using an optocoupler or maybe a solid state relay?
  4. When there is no music, or the level is too low to pick up, the light box is going to be very dull... this led me to the idea of maybe included a simple sequencer comprising of a 555 and 4017 or maybe a 4060. This leads me to the question of whether I should have it automatically switch between sound to light and sequencer, or if I should have a switch and be able to operate it manually?
You ideas, suggestions, input and advice are all very much appreciated.

I look forward to hearing from you.

Kind Regards

Edward Holmes
 
Last edited:

Thread Starter

edwardholmes91

Joined Feb 25, 2013
210
Slight change of plan, I've decided to go down the low voltage route for a couple of reasons:
  1. It will be safer, as there won't be any mains voltages present
  2. It should hopefully be easier to interface at low voltages
As the three channels are currently wired (in series), each channel draws 20mA at 230VDC. By wiring the three channels in parallel, each channel will draw 480mA at 12VDC.

This means I need 1.5A at 12VDC, I've been looking online and I can get a 2A, 12VDC switch mode wall wart for about £10. Also, it has the added benefit that if one of the LEDs fails it doesn't kill one whole channel, as was the case recently.

I'm still looking for a way of interfacing with one of the three circuits I have found, using a microphone and also, how easy it would be to make the controller automatically switch to a sequencer when the audio level is too low to be detected.

I look forward to hearing from anyone.

Kind Regards

Edward Holmes
 

djsfantasi

Joined Apr 11, 2010
9,156
As far as interfacing the microphone to the color organ, I see an amplifier for the microphone. This makes me think of a bullhorn circuit. Click on the link for the results of a Google search. Instead of connecting the output to a speaker, connect it to your color organ.
 

Thread Starter

edwardholmes91

Joined Feb 25, 2013
210
@djsfantasi, thank you for this, I've found the following circuit which looks pretty simple and should do the trick: Power Megaphone Circuit.

I'm struggling to source the HEP230 though, but it does mention any power transistor would be suitable, any recommendations? I've did a search on Rapid Online, would any of those be okay? Ideally, if I don't have to use a heat sink it would be better. I suppose I'm not particularly looking for a really powerful amplifier circuit, just something simple, that will output a signal from the microphone at a similar level to that if I was using a wired connection?

I also found the following: microphone which should be suitable?

Kind Regards

Edward
 
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Bernard

Joined Aug 7, 2008
5,784
I like the first- LED Color Organ. Third better but more complicated than needed. Mic. seems OK.
Adding no sound light show seems doable if a schematic is selected.
 

Thread Starter

edwardholmes91

Joined Feb 25, 2013
210
@Bernard Thanks, that was the circuit that I found first, many years ago and was leaning towards using it, but then found the simpler one. As you say, the final one does look a little more complex than needed.

So here's the plan...

Use Collin Cunningham's[URL] light organ, with [url=http://www.learningaboutelectronics.com/images/Bias-power-to-an-electret-microphone.png]this as an input and then swap out the circuit with IC2 for this negative supply.

All three channels have their own potentiometers, so I have adjustment over the sensitivity of the different filters, which is nice.

I just need to beef up the drivers on the outputs so that they can driver about 500mA or so each, any ideas of what might be a suitable driver?

Kind Regards

Edward[/url]
 

Bernard

Joined Aug 7, 2008
5,784
Here is a preliminarySound Organ 00000.jpg outline to chew on. We tap off the output of IC 1 A & rectify & filter the signal as input to a comparator. ( reverse polarity of comparator inputs ) When a signal is present, output will be low keeping 555 reset, inhibiting random pulse generator. With low or no signal _ where was my brain- my thought was to inhibit random display for a period for short gaps in the music. Assuming that the fill-in program is derived from a 4017 or 4022, the output would be ORd with output stages. A derived darlington output is used as pointed out by Wendy that most power darlingtons have a resistor network on input lowering input Z.
 

Thread Starter

edwardholmes91

Joined Feb 25, 2013
210
@Bernard Hi. thank you for your diagram. I'm affraid I've had to pull the plug on the project. It was starting to get very expensive to source all of the parts that I needed and worked out much cheaper to get a ready built sound to light system which could be used with the unit as is, wired in a series configuration at 230V, 20mA per channel.

Hopefully the start of this project has provided some interest and may prove useful to others in the future.

Over and out.

Kind Regards

Edward
 

marcf

Joined Dec 29, 2014
288
Do you know about this?

https://www.sparkfun.com/datasheets/Components/General/MSGEQ7.pdf


@Bernard Hi. thank you for your diagram. I'm affraid I've had to pull the plug on the project. It was starting to get very expensive to source all of the parts that I needed and worked out much cheaper to get a ready built sound to light system which could be used with the unit as is, wired in a series configuration at 230V, 20mA per channel.

Hopefully the start of this project has provided some interest and may prove useful to others in the future.

Over and out.

Kind Regards
Edward
 
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