Music Controlled Led circuit?

[Siksissk]

Hi,

Im trying to make a simple music controlled blinking circuit. I have found several online already, but they are mostly too complicated.

Im hoping to run somewhere around 20-30 Led's.

If possible something that can be easily sourced from my local electronics store.


Thank you.

 

[Boncuk]

Check out the Elektor (2009/12) issue. There is an RGB-LED-chain project.

The controller can use on-chip programming, RS232 commands and direct analog input off a stereo.

The 30 LEDs won't just blink, but change colour and brightness according to the music you put in.

Boncuk

 

[BrownOut]

There is an identical current thread. Amazing how these questions seem to come in groups. I'll see if I can link it.

 

[Vizier87]

Amazing how these questions seem to come in groups.

My sentiments exactly.

If possible something that can be easily sourced from my local electronics store.

Perhaps you'd get better care buying it online. Farnell.com, Digikey.com, etc. Not that I'm sure if they have what you want, since it's quite specific.

 

[Siksissk]

sorry for the second thread, im not a regular, and couldnt find a up to date thread via the search.

Im currently helping a student at a school with a award hes trying to gain. but I am unfamilar with this side of electronics.

specifically he is trying to obtain a circuit which would turn on and hold a led on untill the a drum beat or a peak in the music, then switch to the next one.

ie.

0 0 0 0 1
0 0 0 1 0
0 0 1 0 0
0 1 0 0 0
1 0 0 0 0
(5 Led's only)
I am trying to keep this circuit simple for him, so I dont want to go into the progamable IC's, but rather to make this into a digital circuit (after making the signal into something usable)

Where im becoming stuck is with the digital circuit, I want to do this in a one-hot style (again for the student) and just to keep things as simple as possible.

Thank You

 

[BrownOut]

I like the concept. An integrated shift register chip such as the 74LS165 clocked by a one-shot that's triggered when the sound level input exceeds a set level comes to mind. Hope you can visualize that, cause I don't have the means to draw a diagram.

EDIT: I should have specified the 74164, and not the 741565. This shift register has the outputs of the individual cells connected to pins, so you can acheive the pattern you want. You'll have to be ingenious enough to preset a bit in the chip and connect a feedback so that the bit is recycled. If you have any experience with digital, that should be pretty simple.

 

[audioguru]

Don't use a lousy old TTL IC. Use a Cmos one instead.

 

[BrownOut]

I linked a cmos 74164. That's the one you want.

 

[audioguru]

What is the part number of a Cmos 74164? I have not seen a list nor an IC for old 74xxx ICs for about 40 years.

 

[BrownOut]

74HC164. The technology isn't critical at all. He just wants to see some pretty lights. The fact that LD logic is old doen't make it non useful.

 

[audioguru]

You don't need a logic IC that has an extremely high max frequency, uses a high supply current and needs a 5V regulated supply.

A simple CD4017 circuit will light an LED for one beat of the music then light a second LED instead for the next beat of the music up to 10, then more CD4017 ICs can be connected if you want. The CD4017 does not need a regulated power supply.

 

[BrownOut]

It really doesn't matter what he uses, just so it works. But the 164 is simple, available, works from 2 - 6 VDC supplies, and only uses 80uA quiescent current. Not a high current supply.

Looking at the CD4017, the advantage is that you don't have to worry about setting the first bit to be rotated, it does that automatically. The power and frequency argements are specious, however.

 

[Boncuk]

I think a circuit using a CD4017 is the simplest solution, concerning bit shift using a shift register.

At 6V VDD the chip can handle frequencies up to 5MHz, more than sufficient for AF-input frequencies.

Here is a circuit recycling after each count to five. The green LED is optional and indicates "READY" when the circuit is powered.

Please note that the LEDs must be low current (2mA forward current). For higher LED current use small signal transistors (e.g. BC547) to drive the LEDs.

R1 may be omitted when the input is used to be connected to an AF-filter output.

Boncuk

 

[audioguru]

The outputs of a CD4017 are typically 17mA into a 3.5V blue or white LED when the supply is 10V and there are no current-limiting resistors. The outpuit transistors will dissipate 110mW for a moment which is fine.

 

[Boncuk]

The outputs of a CD4017 are typically 17mA into a 3.5V blue or white LED when the supply is 10V and there are no current-limiting resistors. The outpuit transistors will dissipate 110mW for a moment which is fine.

I like cool electronics.

 

[audioguru]

I like cool electronics.

110mW is not much heat when you consider that only one output transistor in a CD4017 is on at a time.