Obviously when you are craze to make a fantastic project that will shock your colleague you try to search for electronics projects that are simple and their hardware is easily available. Using 555 timers you can make different sounds by configuring IC in many ways. Here we learn the Police siren circuit. this circuit will widen your knowledge about this ic for future projects.
Hardware Components
The following components are required to make Police Siren Circuit
| S. No | Component | Value | Qty |
|---|---|---|---|
| 1. | Breadboard | – | 1 |
| 2. | Battery | 9v | 1 |
| 3. | Connecting wires | – | 1 |
| 4. | Resistors | 10k,68k,1k | 3,1,1 |
| 5. | Ceramic Capacitor | 10uF,100nF, 1nF | 2,1,1 |
| 6. | IC | NE555 Timer | 2 |
| 7. | Speaker | – | 1 |
555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
Police Siren Circuit
Working Explanation
This circuit has two timer ICs so it generates two sounds low and high simultaneously. Pin 5 of a timer is used as voltage control, we make the first IC as a low-frequency oscillator to control the second IC. The variation in voltage from the output of the primary IC to the voltage control pin of the secondary IC makes the circuit a rising and falling frequency oscillator and the output of the second IC is filtered and passes through the speaker to make Sound
Application
This circuit helps groups or individuals about any accident in indoor and outdoor premises. Generally, the work office makes an emergency exit when the siren is alarmed. We can mount this simple circuit to Application-based circuitry that detects any movements or accidents.
