Basically siren on a police patrol car and an ambulance use electronic circuit connected to the DC current. When the switch is pressed, the siren sounds immediately come out. For those of you who own a car, or any motor you can also create a similar horn. Placement was also very practical. And if you want the flashing lights can add your own. In a series of above do not use flashing lights as the sirens sound. Part List : R1 = 47K R2 = 200R C1 = 0,02uF C2 = 50uF 16V C3 = 0,005uF T1 = 2SB178 PNP transistor S1 = Push button switch G1 = 6-12V battery TR1 , IT transformer is reversed. used a two-legged. TR2 , OT output transformer OT240 How to use it is to put the above series into a box. Adjust the size to be more practical. Then insert the cable of a car or motorcycle battery voltage as described above that is 6-12 V battery into the plug. In accordance with their respective poles. Three feet of IT transformer wrapped so as not to stick to the body of the car or motorcycle. Cover wi...