08-16-2017, 10:03 PM
four tone siren
Operation of four siren sound generator circuit using UM3561, IC1 number ready to create a sound all four sound at pin 7, 8 of IC1 to the R1, VR1 to take to control the frequency of oscillator circuit the internal IC. If the VR1 adjust less frequently and will increase, if VR1 adjusts the frequency that would cost a lot less. When the power supply is integrated into the police car sirens sound out.If the switch S1 will press space, press switch S2 sound gun will fire if the sirens sound, press switch S3 ambulance sirens will sound signals are sent out from pin 3 of IC1 then.Expanded with Q1, Q2, with R1 serves to limit current in pin B of Q1.