Circuit Project Electronic

This be Simple Siren Circuit that build easily. Because of use the transistor 2 pcs only just. Can use 8 ohm size loudspeakers. Which , I uses old loudspeaker , at the sound doesn’t Amen! come to usable with this comfortable circuit. The usability just you presses switch (close) S1 [...]

This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail.
The heart of the circuit is the two transistor flasher with frequency modulation applied to the base of the first transistor. When the pushbutton is depressed, the frequency of oscillation climbs to a peak and when the button is [...]

Parts:
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 45V 100mA PNP Transistors
Q3____________BC337 45V 800mA NPN Transistor
SW1___________SPST Toggle or Slide Main Switch (See Notes)
P1____________SPST Pushbutton [...]