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old idea new twist,want to build a programmable music box can't figure out the hinge circuit Answered

I'm converting a chest into a large music box i need to find a way to have a specific song downloaded to a chip or maybe a old cellphone i thought ,then set up to play when the box opens.I'd really like to know the name of the circuit that works on the principles of two objects separating to complete the circuit. Thanks to anyone who tries


I wouldn't bother with a hinge switch if I were you. A light dependant resistor wouldn't wear as it was used and could be used with an op-amp to make your music play when the box is opened and light floods in.

That's a great idea. No fussin' with adjustments.

An mp3 player is going to be a bear to get to work for this. You'll have to leave it on all the time and figure some way to stop it from playing when the box is closed. I guess you could power it with a wall wart, set it to play and leave it on and playing permently then put the switch in line with the speaker. I don't know if it will be damaged by running without a load (the speaker) connected. Try a recordable door bell. Radio shack used to sell a kit that you could record a message or music for about 45 seconds and it would play back continuously until the switch turned it off. Kind of like those musical birthday cards.

If you look at a regular music box it simply has a spring loaded switch that opens when the pressure of the lid is removed. Google lever switch to find the electronic equivalent.

You want a cheap player - mp3 perhaps? Hack the play button to a switch on the box. You'd need an amp' probably and speakers. Speakers: no problem Amp' : search this site Switch-hack: that's your innovation. L

Any reason why you can't use a normally closed push button? With the box closed the button will be pushed, breaking the circuit. Open the box and the button pops back to normal, making the circuit.