Personal Alarm by BC327

This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord.
If the bag is snatched abruptly, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts oscillating and the loudspeaker emits a loud alarm sound.
The device can be reverse connected, i.e. the box can be placed in a pocket and the cord connected to the bag.
This device can be very useful in signalling the opening of a door or window: place the box on the frame and the magnet on the movable part in a way that magnet and reed switch are very close when the door or window is closed.
Parts:
R1____________330K 1/4W Resistor
R2____________100R 1/4W Resistor
C1_____________10nF 63V Polyester or Ceramic Capacitor
C2____________100µF 25V Electrolytic Capacitor
Q1____________BC547 45V 100mA NPN Transistor
Q2____________BC327 45V 800mA PNP Transistor
SW1____________Reed Switch and small magnet (See Notes)
SPKR___________8 Ohm Loudspeaker (See Notes)
B1_____________3V Battery (two A or AA cells wired in series etc.)

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