Audio amplifiers are electronic devices designed to boost low-level audio signals, such as those from a microphone, to produce high-amplitude signals that can be played through speakers.
This DIY mini amplifier circuit is an ideal introductory project, perfect for those new to electronics. It offers an opportunity to practice soldering skills and impress friends who may not be well-versed in electronics.
Here is a simple and humble 2 Watts mini audio amplifier circuit suitable for small pocket radios and other portable audio gadgets. The circuit is based on Phillips Semiconductors IC TDA 7052. The amplifier can be run even from a 3V Mercury button cell. This makes it ideal for battery operated gadgets.
The TDA7052 integrated circuit (IC) is a monaural (mono) output amplifier packaged in an 8-lead Dual In-Line Package (DIP). It is primarily designed for use in portable audio devices powered by batteries. The key features of the TDA7052 include the following: it does not require external components, it produces no audible clicks when turned on or off, it offers excellent overall stability, it has very low power consumption (only 4mA of quiescent current), low Total Harmonic Distortion (THD), it doesn’t need heat sinks, and it is resistant to short circuits.
The TDA7052 has a fixed internal gain of 40 dB. To compensate for reduced output power when operating with a low voltage supply, the TDA7052 employs the Bridge-Tied-Load principle (BTL). This allows it to deliver an output of approximately 1 to 2 watts RMS (with THD at 10%) into an 8-ohm load when powered by a 6-volt power supply.
In the circuit, a potentiometer can be used to adjust the volume. Capacitors C1 and C2 serve the purpose of filtering the supply voltage when a battery eliminator is used as the power source. However, when using batteries, C1 and C2 are not necessary.
Mini Audio Amplifier Circuit Diagram with Parts List
- Audio input – 1 nos
- Potentiometer – 1 nos
- Capacitor 220uF – 1 nos
- Capacitor 100nF – 1 nos
- IC TDA 7052 – 1 nos
- Power source – 6 V
- Output speaker – 1 nos
- Assemble the circuit on a good quality PCB or common board.
- If you are a little expert, you can assemble the circuit in a match box including the speaker.