Personal Attack Alarm Circuit Diagram

[Gover202]

Hi,
I am completing a design project and I need to use a circuit the same as that in a personal attack alarm or rape alarm.

Simply, when the metal pin is removed, the alarm sounds and when the opin is replaced, the alarm stops.

Would anyone be able to supply the circuit diagram for this?

Many thanks guys,

Jack

 

[shrtrnd]

Is it worth the effort?
You can buy one for less than $10 that runs on a 9v battery.

 

[Gover202]

I need to circuit for a university project, so I need to include the circuit diagram in my work to show how the circuit would be made if it had to be. It is more of a theoretical project than a practical one. I have very basic knowledge of electronics.

 

[jackorocko]

This seems trivial or could I be missing something obvious? Connect a battery to a buzzer and make the pin the switch.

 

[gorgon]

Use a standard 2.5 - 3.5 mm audio jack as the pin should be the simplest.

TOK

 

[davenn]

I need to circuit for a university project, so I need to include the circuit diagram in my work to show how the circuit would be made if it had to be. It is more of a theoretical project than a practical one. I have very basic knowledge of electronics.

this is pretty basic for a university level project !! seriously
any university level project I have ever seen requires some substantial research and design to make it worthy of such a level of education

A buzzer, battery and a switch doesnt really qualify


Dave

 

[CocaCola]

Use a standard 2.5 - 3.5 mm audio jack as the pin should be the simplest.

The jack should have a disconnect upon insert/removal (many jacks ground the signal upon removal of the plug, this will be the switch you use), you need the NO state when the plug is inserted...