High Power Siren...

 
Parts List.

R1,R3_________1K  1/4W Resistors
R2,R5_________10K  1/4W Resistors
R4___________220R  1/4W Resistor
R6___________220K  1/4W Resistor
R7___________22K  1/4W Resistor
R8___________100K  1/4W Resistor

C1,C2_________22µF  25V Electrolytic Capacitors
C3___________10nF  63V Polyester or Ceramic Capacitor
C4___________47µF  25V Electrolytic Capacitor

Q1,Q2________BC557   Transistors
Q3__________ BC337   Transistor

SW1________   SPST  Toggle or Slide  Switch

P1__________  SPST  Pushbutton  Switch

SPKR________8 Ohm speaker

B1__________ 12V Battery