Passive switch alarm system

Step 3 Trigger switches

You can use all sorts of sensors to trigger this as long as no electricity flows.

Here is a list of triggers I am using or ideas I have:

So far I have only used a NC momentary switch but there is room for expansion. The picture is of the switch its horrible I know, my camera flash is not working so I can't really hold the camera still for 7 seconds. sorry.

Normally closed momentary switch - I press the button in so the switch is OPEN and place it against the wood bar in the window, if the bar is removed the alarm is triggered.

Normally open momentary switch - Place is the window slide so if the window is opened too far it sounds

Laser tripwire trigger - I'm still working on this one but you need a photoresistor and a laser. When saturated with light it must create enough of a voltage drop to "leave the switch open"

Vibration sensor - take the fillimant from a light bulb and hang it vertically in the middle of a conductive ring. sensitivity can be adjusted by the distance of the bottom of the fillimant to the ring or the size of the ring