Switch on/off MP3 player by using transistor

Other Hardware General Electronics
21

Yes.
Could replace the logic level p-channel mosfet for a PNP transistor if you don't have one.
At a cost of some switch voltdrop.
Q1 collector circuit needs to be changed for that.
Leo..

22

Thanks.
How much voltage drop will I have?
I will order those references. Any advice about better ones?
Thanks again.

23

Minimal if you use the right fet. The FDN340P seems to be suitable.
Don't expect to find a small logic level P-channel fet in a through-hole package.

Remember I warned you for the signal lines.
Leo..

24

Ok

I'm ordering 2n3904 and FDN340P.
R1=660 ohm
R2=1 kohm

Will the MP3 module be activated on uC High or Low signal?

Thanks again.