Doorbells are quite widespread nowadays in every home. Different sorts of door bells are available in the market, and based on their functionality, they generate different types of sound. Simple electronic components can be used to create one’s own doorbell. This article describes a simple circuit that uses a 555 timer to make a “ding dong” sound Generator.
- Ding Dong Bell Sound Generator Circuit Principle:
- Ding Dong Bell Sound Generator Circuit Diagram:
- Ding Dong Bell Sound Circuit Design:
- How Ding Dong Sound Circuit works?
- Ding Dong Sound Project Output Video:
- Ding Dong Bell Sound Generator Circuit Applications:
- Ding Dong Bell Circuit Limitations:
Ding Dong Bell Sound Generator Circuit Principle:
The basic components of this circuit are two 555 timer ICs. The first timer IC is in astable mode, and the second timer modulates the frequency of the first. The output pin of the first IC is connected to the 5th pin of the second IC in this way. The 1Hz frequency of the first timer IC is used.
The 555 timer IC’s astable mode is a free-running mode. The RC circuit can be tuned to operate the 555 timer IC at the desired frequency. There is no need for external triggering in astable mode. There is no stable state in this.
Ding Dong Bell Sound Generator Circuit Diagram:
- Two 555 timer ICs – U1 and U2.
- Two Variable resistors – RV1 and RV2
- 4 Capacitors – C1, C2, C3 and C4.
- 2 Resistors – R1and R2
Ding Dong Bell Sound Generator Circuit Design:
The circuit is made up of two 555 timer ICs that are connected as shown in the diagram. The first timer IC is wired in astable mode to generate a 1Hz pulse. The 4th and 8th pins are shorted and linked to a 2.2K resistor, the other end of which is attached to the timer IC’s pin. The variable resistor is attached to the sixth and seventh pins. The sixth and second pins are shorted and connected to a 9v ground through a 47uf capacitor. Through a 0.01uf capacitor, the fifth pin is connected to the ground. The IC’s first pin is connected to the ground.
The first IC’s output pin is connected to the second IC’s control pin, which is the fifth pin. The second IC is also switched back to astable mode. The fourth and eighth pins are shorted and linked to a 2.2 k ohm resistor with the other end attached to the IC’s seventh pin. Between the IC’s sixth and seventh pins, a 100K variable resistor is attached. The sixth and second pins are shorted and connected to ground via a 0.1uf capacitor. The first pin is wired directly to the 9v ground. The IC’s output pin is connected to the speaker via a 1uF capacitor.
How Ding Dong Sound Generator Circuit works?
- To begin, turn on the circuit.
- The sound of “Ding Dong” may be heard coming from the speaker.
- The circuit operates in the astable mode when the power is turned on.
- The capacitor begins to charge as the voltage is applied to the timer via the resistors R1 and R2.
- The sixth pin detects it when it reaches 2/3 of VCC, and the seventh pin is connected to the ground.
- As a result, the capacitor begins to discharge through the RV1 resistor.
- When a voltage of 1/3 VCC is measured, it begins charging again, and this process continues to create a 1Hz pulse.
- The control pin of the second timer is used to apply this.
- As a result, the second timer’s frequency is modulated and applied to the speaker through a capacitor.
- The time delay with which the waveform should be formed is determined by the external RC circuit.
- As a result, the sound of “ding dong” can be heard.
Ding Dong Sound Generator Project Output Video:
Ding Dong Bell Sound Generator Circuit Applications:
- The circuit can be used as a door bell by connecting the supply to a switch.
- With some modifications it can be used to produce different sounds.
Ding Dong Bell Circuit Limitations:
- As the applied voltage is 9V, it cannot produce more sound.