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Problem with usb mp3 kid player project

Nafeel

Feb 14, 2018
3
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Feb 14, 2018
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Hi, i am very new for here

I recently build a mp3 & FM radio player by using
  • Usb mp3 Kit
  • PAM8403 5V amplifier
  • 2 3W 4ohms speakers
  • 230 Ac to 5 dc transformer power supply
My power supply is 230v to 6v step down transformer with diode bridge circuit

However, when I connect these together with power supply , something is wrong. On connecting power, the speakers produce loud clicks and players also blink

After i gave power separately
For player from transformer circuit
For amplifier from a 3v dc battery

Then it was fine
I can't catch above problem
Please help me
 

Tha fios agaibh

Aug 11, 2014
2,253
Joined
Aug 11, 2014
Messages
2,253
Sounds like power supply is too small.
Check that the power supply can deliver the current required to drive your load.
 

Audioguru

Sep 24, 2016
3,656
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Sep 24, 2016
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3,656
The absolute maximum power supply voltage for the PAM8403 is 6.0V. Your 230V to 6VAC transformer output might be 7V or 8V AC when not at its full load then the peak is 8V x 1.414= 11.3V and the rectifier bridge reduces it to 9.5V which might destroy the PAM8403 amplifier.
 

Nafeel

Feb 14, 2018
3
Joined
Feb 14, 2018
Messages
3
The absolute maximum power supply voltage for the PAM8403 is 6.0V. Your 230V to 6VAC transformer output might be 7V or 8V AC when not at its full load then the peak is 8V x 1.414= 11.3V and the rectifier bridge reduces it to 9.5V which might destroy the PAM8403 amplifier.

No
I setup & send it through a transistor ic 7805 and some resistor and check the voltage between the amplifier circuit using
multimeter and it shows 3v

Again same problem occurs
 

Audioguru

Sep 24, 2016
3,656
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Sep 24, 2016
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3,656
The 7805 with proper input and output capacitors is fine. Where and why did you add "some resistor"?
 

Nafeel

Feb 14, 2018
3
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Feb 14, 2018
Messages
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The 7805 with proper input and output capacitors is fine. Where and why did you add "some resistor"?
To reduce the voltage
Because pam8403 amplifier circuit get 3v only otherwise the speakers produce loud click
 

Audioguru

Sep 24, 2016
3,656
Joined
Sep 24, 2016
Messages
3,656
To reduce the voltage
Because pam8403 amplifier circuit get 3v only otherwise the speakers produce loud click
A resistor does not simply reduce the voltage. The resistor reduces the current that the amplifier needs then the reduced current reduces the voltage.

Please post a schematic of how you connected everything together. Maybe your PAM amplifier is missing input coupling capacitors or resistors.
 
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