Battery powered alarm which only draws power when in use to extend battery life.
Triggered by the latching switch which represents a micro switch on a door or similar. If the momentary switch (normally open) isn't pressed in time the alarm (bulb) activates and stays open until the momentary switched (normally closed) is pressed.
Momentary switches could be a single dpst or or seperate as shown.
In reality the op amp will be powered after the latching switch so won't output high when the switch is open (not currently an option in EC).
