Audio power amplifier with IC TDA7294 or TDA7293 – #Minimus

# Audio power amplifier with IC TDA7294 or TDA7293 – #Minimus

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Audio power amplifier project based in integrate circuit TDA7294 or TDA7293. Compact printed circuit board and is ideal to be used where a compact amplifier and with adequate power to be used in various applications, such as computer amplifier necessary, games, Mp3 Player, Home Theater, Sound environment, amplified Cash, etc.

### Features power amplifier using integrated circuit TDA7294 or TDA7293

• Classic application using the IC TDA7293/TDA7294
• To assemble with TDA7294 or TDA7293 just by changing the position of a capacitor.
• Great audio quality
• Easy assembly.
• Uses just a few components in the assembly
• Reduced size board 50mm X 36mm
• Power -/+ 18-36 VDC (Symmetrical power supply)
• Maximum power: 80 (7294) -100 (7293) Watts RMS
• Output Impedance: 4 at 16 Ohms.

### Suggestion of printed circuit board for assembly of mini amplifier

The transformer is connected at the power supply should be able to provide power equivalent to 1.4X the amplifier power. This power is on the DC voltage used.

In the chart below we can see what will be the maximum power, by matching Po(W) and Vs(+/-).

Eg: for 25V => 60W and 30V => 83 Watts. This when connected to speakers of 4 Ohms. This THD to 0.5%.
Note that for 4 Ohms the maximum is +/- 30VDC for TDA7294.

Below is the chart to TDA7294 linked into 8 Ohms – The power supply can be up until +-36VDC.

To determine what will be its maximum DC voltage according to the transformer using the following formula: Vf = (1,4 x Vi) – 0,5
Where: Vf = final voltage
Vi = Voltage in the transformer

Ex: For a 24-0-24 transformer have:
Vf= (1,4X24) – 0,5 = 33V

Ex: Transformer for +/-28VDC
28=(1,4xVI) – 0,5 = 1,4Vi=28-0,5 = Vi =27,5/1,4 = 19,64C

With this value at hand just go on the chart and find what will power for this case!
For TDA7293, see the Datasheet
Notice the layout how to assemble the capacitor properly for TDA7294 or TDa7293.

#### List of material to assemble the amplifier Minimus Power Series with TDA7294 / 93

 Part Value Resistors 1/4 W 5% R1, R3, R4 22K – Red, Red, Orange, Gold R2 680 – Blue, Grey, Brown, Gold R5 10K – Brown, Black, Orange, Gold R6 33K – Orange, orange, orange, gold R7 4.7 Ohms – Yellow, Violet, Gold, Gold Capacitors C1, C2, C3, 100nF/100V – Ceramic capacitor or polyester. C4, C7 22µF/50V – Electrolytic capacitor C5, C6 47µF/50V a 220µF/50V – Electrolytic capacitor C9 1µF/100V – Capacitor Polyester C10, C11 10µF/50V – Electrolytic capacitor Semiconductors D1 1N4148 – Semiconductor diode IC1 TDA7293 or TDA7294* -Audio amplifier integrated circuit. Connectors IN Audio input connector PW Power supply connector OUT Audio output connector Miscellaneous Welding, Wires, PCB, box,power supply 18 a 36 Volts DC /2,5 Amperes, etc.