Why do we need a buzzer in a circuit?
Buzzer is an electrical device that is used to get a buzzing or beeping sound when a potential difference is created or voltage is applied.
A buzzer is understood as a device that creates an audible tone under the influence of an applied external voltage. This output may either be in the form of a buzzing or a beeping sound.
Conversely, if you apply a voltage across a piezoelectric element, it will slightly flex. Piezoelectric buzzers rely on this process to create vibrations. The buzzer applies a voltage across the piezoelectric element thousands of times per second which flexes the piezoelectric element to create noise.
It's simple, tone(buzzer, 1000) sends a 1KHz sound signal to pin 9, delay(1000) pause the program for one second and noTone(buzzer) stops the signal sound. The loop() routine will make this run again and again making a short beeping sound.
Buzzer. A buzzer converts electricity into sound when current flows through it. It is drawn as half a circle with two short lines extending down.
The buzzer and an electric bell also uses electrical energy as input and they have slightly different circuit designs to produce different sound effects. But the output energy is released in the form of sound waves.
Buzzer is a kind of voice device that converts audio model into sound signal. It is mainly used to prompt or alarm. According to different design and application, it can produce music sound, flute sound, buzzer, alarm sound, electric bell and other different sounds.
Output devices allow a system to present information back into the 'real' world. Examples can be seen everywhere, from car indicators to doorbell buzzers or information displays.
When current passes through the wires inside the bulb, electrical energy changes into heat energy and light energy. Similarly, when current passes through a buzzer, electrical energy changes into sound energy.
Like you have mentioned resistors are used to limit current flow. Since the buzzer already takes only a very small current, we do not want to resist that current. That's the reason we do not use a resistor with buzzer .