Hi all,
Can somebody please take a look at this circuit (in the link below) and tell me why they dont just use a normally closed reed switch attached directly to a buzzer.
http://freecircuitdiagrams4u.blogspot.com.es/2010/01/simple-door-alarm-circuit.html
I notice that it is common to use normally open switches in door alarms but I dont understand as surely having a circuit break rathern than make when the door is opened is the opposite of what you need!
Thanks in advance
Adam
Can somebody please take a look at this circuit (in the link below) and tell me why they dont just use a normally closed reed switch attached directly to a buzzer.
http://freecircuitdiagrams4u.blogspot.com.es/2010/01/simple-door-alarm-circuit.html
I notice that it is common to use normally open switches in door alarms but I dont understand as surely having a circuit break rathern than make when the door is opened is the opposite of what you need!
Thanks in advance
Adam