Either the switches activate the battery or they activate the trigger circuits (probably both).<p>I should also note that, unless you had extremely detailed pictures of the switches themselves (or part numbers), you could easily use a combination of switches which appears to do one thing but instead does another, so X-Rays and a wiring diagram wouldn&#x27;t necessarily be helpful in discovering the actual path of electricity. You could maybe do something clever with a very sensitive electrometer, but that would take way too long.<p>Arming it doesn&#x27;t seem like the hard part to me. I think the hard part, with all the foil based triggers and spring loaded screws, would be construction and QA and making sure you don&#x27;t kill yourself activating the thing because there&#x27;s some filings completing a circuit you didn&#x27;t know about.