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How to Create a Buzzer Circuit

A buzzer circuit can be used to sound an audible alert or alarm. It consists of a switch, an output device (such as a speaker or piezo buzzer), an alternating current signal generation mechanism and a power source. A simple buzzer circuit can be constructed using a few items that can be found at many local electronics supply stores.

Things You'll Need

Electrical wire
Electrical pliers
Electronic solder
Soldering iron
555 timer integrated circuit
1-kiloohm resistor
6.2-kiloohm resistor
51-ohm resistor
0.1 microfarad nonpolarized capacitor
100 microfarad nonpolarized capacitor
8-ohm speaker
Toggle switch
Battery snap connector
9-volt battery

Instructions

- 1
  Cut 11 pieces of wire, each 3 inches long. Strip off 1/2 inch of insulation from the ends of each wire segment.
- 2
  Twist one end of the first wires to the "ground" terminal (Pin 1) on the 555 timer. Melt a small drop of solder to both the wire and to Pin 1, and smooth out the soldered joint with the tip of the soldering iron. Ensure that the soldered joint is shiny and free of lumps.
- 3
  Twist one end of the second wire to the "trigger" terminal (Pin 2) on the 555 timer. Twist one end of the third wire together jointly with the free end of the second wire, and solder the twisted wire pair to the "threshold" terminal (Pin 6) on the 555 timer.
- 4
  Twist one end of the fourth wire to the "discharge" terminal (Pin 7) on the 555 timer and solder this electrical joint.
- 5
  Twist one end of the fifth wire together with the "reset" terminal (Pin 4) and solder this electrical joint. Twist the free end of the fifth wire, one end of the sixth wire and one end of the seventh wire together with the "+VCC" terminal (Pin 8) and solder this electrical joint.
- 6
  Twist one end of the sixth wire together with one of the leads from the 1-kiloohm resistor, and solder this electrical joint. Twist the free lead of the 1-kiloohm resistor together jointly with the loose end of the fourth wire, along with one of the leads from 6.2-kiloohm resistor. Solder this electrical joint.
- 7
  Twist the loose end of the fourth wire together jointly with one of the leads from the 0.1-microfarad capacitor, and with the free lead from the 6.2-kiloohm resistor. Solder this electrical joint.
- 8
  Twist together one end of the eighth wire with the free lead from the 0.1-microfarad capacitor. Solder this electrical joint.
- 9
  Twist one end of the ninth wire to the "output" terminal (Pin 3) on the 555 timer and solder this connection. Twist one of the leads from the 100-microfarad capacitor to the free end of the ninth wire and solder this connection.
- 10
  Solder the free lead from the 100-microfarad capacitor to one of the terminals on the speaker. Solder one end of the 10th wire to the remaining speaker terminal.
- 11
  Solder the loose end of the seventh wire to one of the terminals on the switch. Solder one end of the 11th wire to the remaining switch terminal.
- 12
  Twist together the loose end of the 11th wire to the red wire on the battery snap connector and solder the electrical connection. Twist together the loose ends of the first, eighth, and 10th wires with the black wire from the battery snap connector, and solder the electrical connection. Turn on the switch to actuate the buzzer.

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