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putting a resistor in series with a speaker to increase the impedence

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JS:
NTC is what's used to limit inrush, no need for resistor and bypassing as this devices do all for you

JS

Zero999:

--- Quote from: JS on July 25, 2018, 04:39:04 pm ---NTC is what's used to limit inrush, no need for resistor and bypassing as this devices do all for you

JS

--- End quote ---
I'm doubtful an NTC resistor will work in this application. If this were for a motor or incandescent lamp, I'd agree, but I'm not sure it'll work here.

An audio amplifier will draw huge peak currents, along with a very low quiescent current, so I don't think the resistor will heat up enough to reduce its value low enough, to power the circuit. I think the value of the NTC resistor will stay high, after power on, causing the supply voltage to collapse, resulting in lots of distortion, as soon as the beat drops.

Seekonk:
If it is just a thump that worries you, Add that resistor in series with the speaker and just add a 470uF capacitor in parallel with that.  Soles the low resistance DC startup without changing audio much.

Zero999:

--- Quote from: Seekonk on July 25, 2018, 04:51:32 pm ---If it is just a thump that worries you, Add that resistor in series with the speaker and just add a 470uF capacitor in parallel with that.  Soles the low resistance DC startup without changing audio much.

--- End quote ---
How would that help?

The capacitor would just bypass the resistor at AC, causing the thump to happen anyway. The resistor won't do anything!

Adhith:

--- Quote from: Hero999 on July 25, 2018, 04:26:12 pm ---Why not just use a 555 timer?


--- End quote ---
Thank you very much Sir for your reply. I'm trying to solve this issue with a 555 timer which you have suggested in my other thread( 555 timer circuit for 5 seconds).


--- Quote from: Hero999 on July 25, 2018, 04:26:12 pm ---In this case, I think this has nothing to do with the speakers. You'll probably find the board still draws a huge inrush current, even with the speakers disconnected. Refer to the circuit on page 5 of the data sheet. It has a 1000µF capacitor (C32, next to J2) across the power rail, which is probably causing the problem.


--- End quote ---
I had connected an ammeter across the amplifier board to see the current draw. As I mentioned before the current draw was about 1.8A at the start up and then reducing considerably. But when I disconnected one speaker the current draw is only about 1A and the BMS is driving the amp smoothly without any trouble. So I guess there is some rush of current to the speaker during start up or I'm totally wrong??
Another thing about the amp board is that, it plays a music at the startup of the amp and the BMS is shutting down just before that music is played. So does this means that the startup music is drawing all this current??

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