Bluetooth Amplifier interference from 5v LEDs

Discussion in 'The Projects Forum' started by ToneG, May 5, 2016.

  1. ToneG

    Thread Starter New Member

    May 5, 2016
    3
    0
    Hi
    I have built a Bluetooth powered speaker using Bluetooth usb module and small amp.
    With 5 colour changing LEDs running off the same power supply of the above I get a changing wine noise almost as the LEDs change. With the LEDs switched off, that noise is gone.

    Any recommendations on how to solve ?

    Many Thanks
    Tone
     
  2. Marcus2012

    Member

    Feb 22, 2015
    349
    26
    What power supply are you using? and what is its rated current draw? Sounds like you are drawing too much current when the LEDs switch on which is superimposing noise over your audio signal. If you're powering this from a PC USB socket chances are you only have 100ma available which is probably what the 5 LEDs need on their own.
     
    Last edited: May 5, 2016
  3. ToneG

    Thread Starter New Member

    May 5, 2016
    3
    0
    Powering either from a usb battery pack on 2.1ah output. Also does the same on USB adapter plunged into the wall.

    I'm going to see if I can recreate this on a breadboard over the weekend.
    Was hoping to solve noise with just components but maybe try a higher input voltage say 12v then split it and step it down to 5v for the Bluetooth and amp but leave at 12v for LEDs via resistor ?

    I had read about mains LED light fittings causing interference but presumed this would not be the same.
     
  4. ToneG

    Thread Starter New Member

    May 5, 2016
    3
    0
    Thought LEDs were interfering with the Bluetooth module but even with the Bluetooth unpowered disconnected interfering via the Pam8403 amp. Tried separate power but think it's the closeness of LEDs to amp.
     
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