Sound Reactice LEDs

[nulleth]

Hello,
Im embarking on my first electronics project in 10 years, and im keeping it fairly simple for myself.
Heres the general plan:

Sound Activated LEDs Powered By 12Volt PC PSU.
I know there are some Cold Cathode(with inverters) versions out there, but I wanted to go for LEDs to keep noise and heat down.

Heres my plan:
Sound Kit:
**broken link removed**
https://www.electro-tech-online.com/custompdfs/2009/12/manual_mk103_rev1.pdf

LEDs:
**broken link removed**

Now, the Sound Kit has everything I need and can be powered by the 12v's from my PSU.
It also includes 4 basic LEDs on the pcb.

Apparantly the sound-kit is reactive, depending on sound levels different LED's or intensity lights up, im afraid I can't tell which...does anyone know?

Also, im looking to change the LEDs to something brighter or more fun:
**broken link removed**
That light strip looks great, maybe it would be possible to have the intensity of the lights react to sound levels?
Alternatively, something like this:
Lamptron 5 Spread Lazer LED Psycho Slow

Anyway, any hints, tips, or answers would be most welcomed!
Thank you!!

 

[kchriste]

Apparantly the sound-kit is reactive, depending on sound levels different LED's or intensity lights up, im afraid I can't tell which...does anyone know?

All the LEDs will flicker exactly the same, in time with the sound level fluctuation.

Also, im looking to change the LEDs to something brighter or more fun:
**broken link removed**

You might have to add another transistor to boost the current depending on how many light strips you want to run.

 

[nulleth]

Thank you for the help!
You mention they will flicker in time, will their intensity change or is it just On/off ?
If I just connected the system to a 12v connector, instead of using the 9v battery and then use the Blue LED Strip seen in my links instead of the LEDs...will that work just fine?

 

[kchriste]

You mention they will flicker in time, will their intensity change or is it just On/off ?

They basically just turn ON during the audio peaks. How much they turn on depends on the audio level and the setting of RV1. They will appear to change intensity a bit due to volume level because they will be ON for longer periods of time as the volume goes up.
You may want to look for something called a "colour organ" if you want a more exciting display. Usually they are main voltage projects, though I've seen some that use LEDs. I don't think Maplins makes a kit though.

If I just connected the system to a 12v connector, instead of using the 9v battery and then use the Blue LED Strip seen in my links instead of the LEDs...will that work just fine?

Basically yes. It is hard to say if the strip already has a built in current limiting resistor/diode. The website implies that it does and that it'll run off a regular 12V supply. If so, you could replace R9 with a jumper and connect the LED strip where the original LEDs were. The PCB will support 1-2 5cm LED strips. If you want to run more, you'll need to add another transistor for more current.

 

[nulleth]

Thanks very much for your help.
Would you know how I can work out what transitor would be required?
Im slowly getting back into all this, still a little daunting, but you have been a great help.

 

[kchriste]

Would you know how I can work out what transitor would be required?

That would depend on how many LED strips you want to use. If not too many (10 or less) you could simply sub a darlington, such as a BC516 (Pin out may be different), for T4. That would give you enough current gain and current capability to drive 10 LED strips at 20ma each.

 

[nulleth]

Hi,
I just tried recreating the original schematic in Tina 7.
However, I can't see, to get the LEDs to light up.
I don't have a "mic", so I just added a switch and then tried simply missing it out alltogether, but nothing makes the LEDs light.

Could someone please take a look for me?
Oh btw, the potentiometer is set to 40%, tried higher and lower settings, still nothing.

**broken link removed**

 

[kchriste]

I'm not familiar with Tina7, but it looks like you need to supply an AC source to where the mic was. I think it is the 4th one over from the left with the ~ symbol. Try sourcing between 0.1-10mVac @ 1Khz and see what happens.

 

[nulleth]

The fourth one along was DC, and didnt do anything
I put a volt meter and amp meter in its place:
12v and 1.19mA showed up.

Can't think what else to do.

 

[kchriste]

The fourth one along was DC, and didnt do anything

Find an AC one in the menu. That is what you need. Maybe the same icon just needs a frequency specified to make it AC. Someone else here may be familiar with Tina and will chime in soon.

I put a volt meter and amp meter in its place:
12v and 1.19mA showed up.

That sounds right. That is the mic bias voltage/current supplied via R1. The voltage would be much lower than 12v if a real mic was in the circuit.

 

[mneary]

There needs to be a dot (connection) at the junction of C2, R5, R7, and base of T2.

 

[nulleth]

Hi,
Thanks for your help, made a few changes.
I've found that the the current system still doesn't work...heres a new diagram:
**broken link removed**

If I increase the batter to 24v, it turns on...so im presuming its a transistor or resistor issue.
Does anyone else have any other ideas?
Would really appreciate it!

 

[audioguru]

The 220k volume control seems to be set too low.