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Topic: [SOLVED] by8001 - Standby mode - Speaker consums 300mA (Read 479 times) previous topic - next topic

tahitibob35

Sep 25, 2016, 01:07 pm Last Edit: Sep 27, 2016, 07:39 pm by tahitibob35
Hi
I just received the BY8001 MP3 player.
I connected a speaker (8ohms, 1A).
When I switch the module to the standby mode, the module still consums 300mA.
When I disconnect the speaker, the module consums 3mA.

Do You know if I can add a P2N2222A transistor to power off the speaker ?
Is there any other solution ?

Thanks !
David.

Grumpy_Mike

Sounds like you need a big capacitor in seriese with your speaker to remove any DC component through the speaker.

tahitibob35


Grumpy_Mike

#3
Sep 26, 2016, 07:57 pm Last Edit: Sep 26, 2016, 07:58 pm by Grumpy_Mike
Could You explain this please ?
I though I had done?

If the module draws more current with the speaker attached but no sound being produced then there must be a DC path through the speaker. This is bad because:-
1) Speakers don't like DC through them and it can damage them.
2) You are using current for no reason.

Therefore to stop DC going through the speaker you put a large capacitor in series with the speaker. This blocks any DC but still lets the audio through. This is called AC coupling. I am surprised it was not already included in the amplifier but there is all sorts of crap about these days.

tahitibob35

I like to understand what I do.
Which capacitor value ?
Thanks for explainations !

Grumpy_Mike

#5
Sep 26, 2016, 08:08 pm Last Edit: Sep 26, 2016, 08:08 pm by Grumpy_Mike
Quote
Which capacitor value ?
Anything from 100uF to 10000uF.
The bigger the capacitor the better the low frequency response. Put the +ve end of the capacitor to the amplifier output and the -ve end to the speaker. I assume the other end of the speaker goes to ground.

tahitibob35

Hi
I didn't correctly the documentation.
I connected the speaker between SPK1 and GND.
This is wrong.
Now, the speaker is connected between SPK1 and SPK2 :
50mA when playing
10mA in standby mode

Thanks !

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