was wondering whether I should get Google "websecuritysystems.com" wireless motion detectors or just the normal types.
I got this much from somwhere:
"• Open-circuit systems – With an open circuit what happens is when somebody opens the door the open-circuit is completed and electricity starts flowing so the alarm is set off.
• Closed-circuit systems – Using this system as long as your door is closed the electric circuit remains closed and whenever somebody opens the door, the circuit becomes discontinuous, and the alarm is triggered."
But I cannot get much meaning out of it.