Hi All,

I have an analog amplified mini speaker that I would like to make some modifications to:

The amplified mini speaker as is out of the box:
-There is an internal battery that is charged when connected via micro USB . The speaker cannot operate when the battery is charging
-There is a push button on/off switch
-analog audio in is through a 3.5mm male jack (not through USB port)

What I would like to end up with:
-eliminate the battery and have it powered via hard wire to a DC power source (can be a separate wire, does not need to utilize existing micro USB port)
-eliminate the power switch so that is simply on when power is supplied and off when power is disconnected. I tried disconnecting the existing battery and connecting to a DC power supply and the speaker worked fine BUT it still requires turning on the power switch. And when the power is disconnected it appears the power switch re-sets so turning on the power switch is required every time power is connected.

No changes needed on the audio in and audio out.

Thanks!!

 

What happens if you keep that push button pressed all the time?
If it serves your purpose, you have the answer.

 

The power on switch is what is called a soft switch. It’s an input to a controller on the board. The controller enables an output which turns on a “ power transistor”.
It may be as simple as bypassing the “power transistor”

 

i assume the control input is just a high-z input line that is pulled up with a R and is pulled to ground when u press the button, so it may be possible to just put a capacitor across the button. So when the control chip is powered up the control input will go low for long enough to trigger. Then put a bleed resistor across the cap.

 

What happens if you keep that push button pressed all the time?
If it serves your purpose, you have the answer.

holding the button in constantly appears to have no affect on how it operates ...

 

Keep that button pressed.
Apply power.
Does the unit come ON? And remain ON?

 

Keep that button pressed.
Apply power.
Does the unit come ON? And remain ON?

when keeping the button presses and applying power, the unit does not come on ....