Simple Subwoofer Amplifier Circuit using IC TDA7294

The TDA7294 can be used in a subwoofer amplifier circuit to increase the low frequency bass signals that get to a subwoofer speaker.

An integrated circuit made expressly to function as an audio amplifier is the TDA7294.

The TDA7294 is a monolithic integrated circuit, or one chip that comes in a multiwatt 15 package.

It is appropriate for powered loudspeakers home stereo systems, and even expensive TVs since it is especially made to operate as a class AB audio amplifier in high fidelity Hi-Fi applications.

Circuit Working:

Parts List:

To maximize the performance of this amplifier circuit, use a 150 watt subwoofer speaker with an 8 ohm resistance.
If you can only find capacitors rated for 30V, use those instead of ones rated for at least 50V.

Higher voltage ratings offer more dependability and improved performance.

The advanced features pins are Vm and Vstby.

Leave them disconnected if you are not in need of them.

To prevent unexpected behavior just make sure that these pins are not experiencing any voltage.

Provide the audio signal from your music source to the TDA7294s non inverting input pin.

To create a simple volume control, place a 10,000 ohm variable resistor between the non inverting input pin and the audio input.

This circuit is simple to construct for prototyping on a standard solderless breadboard.

Attach a twin 30V power supply to supply the circuit with the required voltage after it has been built.

Formulas:

When designing a subwoofer amplifier circuit with the IC TDA7294 factors like thermal management, speaker impedance, power supply voltage and gain settings must be taken into account.

The following are the essential elements and formulas needed to create such a circuit:

Calculating Gain:

The circuits feedback resistors may be used to change the amplifier circuits gain.

The gain dB (Gain) is found using:

G_dB​ = 20log₁₀​(R_f / R_i​n​​)

where,

• Rf is the resistor used for feedback, and Rin is the resistor used for input.

Calculating Output Power:

The following formula may be used to determine the maximum output power Pout that may be supplied to the speaker:

P_out​ = V_peak^2​​ / 2R

where,

• The speaker impedance 8Ω is represented by R, while Vpeak represents the peak voltage swing across the speaker.

You may successfully create a subwoofer amplifier circuit with the TDA7294 IC by adhering to these instructions and computations.

Modify component values according to your subwoofer applications particular needs and performance objectives.

How to Build:

To build a Simple Subwoofer Amplifier Circuit, below mentioned are the steps for connections:

• Gather the necessary components as shown in above diagram.
• Connect pin 1 of IC1 to ground.
• Connect pin 2 of IC1 to ground through capacitor C2 and resistor R2.
• Connect pin 3 of IC1 to audio input through capacitor C1,connect from pin 3 to ground resistor R1.
• Connect pin 4 of IC1 between ground and resistor R1.
• Connect pin 6 of IC1 to one end of 8ohm speaker and other end of speaker to ground, connect positive side of capacitor C5 to pin 6 and negative side to 8 ohm speaker.
• Connect pin 7 and pin 13 of IC1 to positive supply of 30V.
• Connect pin 8 of IC1 to ground through capacitor C9.
• Connect pin 9 of IC1 to ON/OFF switch through resistor R4.
• Connect pin 10 of IC1 to ON/OFF switch through resistor R5.
• Connect pin 14 to pin 2 of IC1 through resistor R3.
• Connect pin 15 of IC1 to -30V DC.
• Connect capacitor C4 positive end to pin 9 and negative side to ground, connect capacitor C3 positive end to pin 10 of IC1 and negative end to ground.
• Connect capacitor C8 negative end to pin 15 of IC1 and positive end to ground.
• Connect capacitor C6 and capacitor C7 from positive end to ground.
• Connect resistor R6 and capacitor C10 from pin 6 to ground.

Safety Nates:

• When the circuit is switched on, take care not to come into contact with any live components since the power source has the potential to provide high voltage.
• To avoid short circuits and possible fires, make sure that all connections are adequately insulated.
• When the TDA7294 operates, heat is produced, to avoid overheating and damage, always use a heat sink that is appropriately sized and connected to the IC.
• For the particular circuit design you are working on, choose a power supply with the right current ratings.

Conclusion:

You may add strong bass to your music system by building a TDA7294 subwoofer amplifier circuit, but make safety your first priority.

Employ the appropriate parts control the heat using a heat sink and operate in a well ventilated space.

Consider beginning with a smaller project first if you are new to working with electronics.

References:

Datasheet IC TDA7294