Introduction
Every public addressing events use a microphone and speaker, as it is an important part of any public event. In many events, speakers are used to just play music from any music player or mobile phone. So, if you are a learner of electronics or have an involvement in electronic devices and circuits, then you must have thought that how the internal circuitry of this may work. Basically, these kinds of systems have amplifiers in them which amplify the audio signals coming from any device or human vocals. In simpler words amplifiers increase the low-power input electronic audio signals at the output. To understand amplifiers, in this tutorial, we are going to make “IC555 as an Amplifier”
Hardware Required
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | NE555 Timer | 1 |
| 2. | Loudspeaker | 8Ω | 1 |
| 3. | Condenser Mic | – | 1 |
| 4. | Transistor | BC547 | 1 |
| 5. | Capacitor | 0.1uF, 1uF, 1nF, 10uF | 1,1,1,1 |
| 6. | Resistor | 47KΩ, 680KΩ, 100KΩ, 1KΩ, 10KΩ | 1,1,1,1,1 |
| 7. | 2-Pin Connector | – | 2 |
Circuit Diagram
Working Explanation
In this IC555 as an Amplifier, the condenser mic is biased with the power supply with the help of a 47K resistor and output are collected from the mic. Since this range of output voltage from the mic is in millivolts, therefore, you amplify the voltage. You can say that we need a pre-amplification there. Thus, for this purpose, the BC547 NPN transistor is there which operates as a preamplifier. We connected the output from the transistor with the control terminal pin 5. Now; IC555 provides changed PWM output depending on input coming from the mic. We connect the loudspeaker at the output pin 3. The capacitor is driving the speaker.
Application and Uses
- In audio boosters.
- Portable music players or amplifiers.
- FM radio amplifiers, etc.
