Turn Buzzer into a Siren - Help Me

Discussion in 'General Electronics Chat' started by collegekid00, Apr 6, 2009.

  1. collegekid00

    Thread Starter New Member

    Apr 6, 2009
    I'm trying to take a buzzer and make it a whooping siren. Thus, I thought I would use a capacitor, but it isn't working out good. The buzzer is just buzzing at a constant pitch.

    Here's the circuit I have going:

    3.3 volts in series with a 1000 ohm resistor in series with a 47 micro farad capacitor. The buzzer is also in series in front of the resistor.


    I tried adding a 555 timer and had a period of one second but it doesn't provide a varied pitch, just on and off now.

    Specs on Siren:
    2800 Hz
    1.5 to 5 VDC
    .3 to 4 mA

    At 3.3V, I calculated the current to around 3.3 mA so I should be good.
  2. beenthere

    Retired Moderator

    Apr 20, 2004