One of my students in Kenya, Africa needed a suggestion for a project that would be simple and rninexpensive! I suggested a vibration monitor that could be used as an intrusion alarm. To make sure that it would work, I built my own. Since project cases always drive up the price of a project, I thought, "Why not put the project into a battery holder?"rnEagle Plastics makes a three AA battery holder with a switch. I designed a circuit board the size of a AA battery that would hold all the components (total of nine), and used the center battery slot to power and hold the board.
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