Hi,
I am looking to create an electronic music box. I am using a cheap MP3 player and a simple audio amp circuit to power the speaker. Except I still need to trigger the mp3 player to play when the box is opened. The difficulty is that the MP3 player's switch only needs to be momentarily pushed. If I use a switch that is simply open when the lid is on and closed when the lid is off the MP3 player will just cycle through on and off while the lid is open instead of playing music. Can anyone think of a work around, or special switch that would momentarily push the MP3's power button when I open the top of the box?

Thanks!
Eschatt

 

We do not know the machanical layout is, but in generalities, a pneumatic plunger with air bleed should work; something like timer used in model aircraft free flight timer. Woops- time to go bowling, will come back with sketch.
A 174 game, forgot other two. Mechanically , pneumatic delay switch would be a little too complicated, probably best to hack switch, and bring out two leads.

 

You just need a 555 monostable and a switching transistor to switch the input. The pushbutton on the MP3 player is probably connecting the input to ground when pressed but you will have to check.