Electronics

[sagnik]

Anyone have knowledge on electronics?

[nyten]

That depends on the field ... what it is about?

[sagnik]

I want to create a circuit board with 50 LEDs, 25 is for left channel and 25 is for right channel. The LEDs will blink on music. Without any complex electronics. I've already made it, but the power is too low. I've used 9 LEDs, 9V Battery, TIP-31 Transistor, 3.5mm Audio Connector (male) & Vero Board. How can I do this?

[nyten]

ok a 2-channel light organ.

I have found a circuit diagram of a 3-channel light organ with one LED per channel which can be modified well.

Do you have the datasheet of the LEDs?

A 9V battery may only last a few hours (depends on the power of the LEDs)

[sagnik]

I think I don't have a datasheet. What do you mean by datasheet of LED?

[nyten]

Electrical characteristics like forward voltage and max current.

[sagnik]

Forward Voltage: 3V

Max Current: 20-25mA

[nyten]

Is the brightness sufficient when a LED is operated at 2.9V or even 2.8 V?

if so:

Are the LED's bright enough when you connect 3 in row with the transistor to 9v? Otherwise the audio signal needs to be amplified.

[sagnik]

No, the LEDs are not bright.

[nyten]

No, the LEDs are not bright.

While operating them at 2.9V, 2.8 V or 3 leds in row with the transistor?

 

In my view, the input signal must be amplified anyway because the base current will be too low. I's suggest to solve it with an operational amplifier.

If one led isn't bright enough at 2.8V, I would replace the transistor by a Mosfet.

 

But there are certainly also other ways than my suggestion.

 

*datasheet: Collector-Emitter Saturation Voltage = 1.2

sry, i didn't read that earlier. (7.8V remaining->) 2 in row with a resistor

Edited February 9, 2016 by nyten

[sagnik]

Can you give me the diagram?

[nyten]

http://www.dieelektronikerseite.de/Pics/Circuits/3%20Kanal%20LED-Lichtorgel%20S01.GIF (http://www.dieelektronikerseite.de/Circuits/3%20Kanal%20LED-Lichtorgel.htm)

(3 frequency spectra)

 

There are many more variants, simply search for "led organ". :)/&--#62;/&--#62;

[sagnik]

Here is my circuit diagram. It has 4 LEDs but, I've used 3 rows of LEDs, each rows have 3 LEDs. In total I've 9 LEDs. Everything is working fine but, the problem is that, the LEDs are not bright enough. And I've a 9v Battery, a TIP-31 Transistor.

[nyten]

I think the music-voltage is too low to provide sufficient base current. http://img.xyro.tk/16041190926.jpg

*you can check it by using a 1,5V battery instead of your music signal. But don't forget the base resistor!!

 

I'd urgently recommend to use a base resistance, this can prevent a high, uncontrolled base-current.

[sagnik]

Ok, if I connect it to a pc, then will it work?