Brutus – Circuit Audio power Ampli�er stereo with tda7294
bridge 2x 170 W
July 29, 2011
TDA7294 Bridge stereo 3D Board
The circuit of the amplifier with TDA7294 was a big hit among our readers, so bring more than this version of the amplifier with TDA 7294
“Brutus,” this is an application bridge to the tda7294 that can provide up to 170 Watts @ 8ohms, 38 VDC.
The TDA7294 integrated circuit developed by SGS Thompson (www.st.com), allows you with little money, have a complete amplifier, it is
designed as an AB class audio amplifier and is ideal for use in home systems Theater and high quality amplifiers for easy assembly. It is
capable of working with 4, 8 and 16 Ohms loads (speakers). It is capable of delivering 100 Watts @ 4 Ohms, VS = + – 29V, 100 Watts @ 8
Ohms, Vs = + – 38V. The total distortion is only 0.1% at PO = 0.1 to 50 Watts and F = 20Hz at 20KHz.
In this version of Bridge or Bridge amplifier, keep in mind the impedance of the speakers! 8 Ohms is the minimum recommended is 16 ohms
using only voltage up to +38Volts.
R = 8 Ohms VS =+25VDC, PO = 150 Watts
R = 16 Ohms Vs = +35VDC, Po = 170 watts
Diagram of Brutus – Schematic circuit ampli�er with TDA 7294 – 170 Watts x2 – click for enlarge
TDA7294 Bridge stereo schematic
The circuit is divided into two main parts the power supply and the power amplifier.
Power supply for Brutus – The power supply is composed of a 18018 to 26026 @ 350VA transformer, The bridge rectifier must be a
GSIB2580 or equivalent, the capacitors can be from 4.700μF/50V Up to 10.000μF/50V. There are also 2 ceramic capacitors and 2 resistors,
the function of these resistors is to discharge the large electrolytic capacitors, when you turn off the circuit.
Power amplifier – The amplifier part is configured to work in stereo bridged stereo, using 4 integrated circuits, resistors R11, R12, R17,
R18 (R) and R13, R14, R20, R21 (L) determine the gain of the amplifier. With these components is set to 30 dB. The mute/Standby circuit
is connected directly to the VCC of the circuit. The input impedance is determined by the resistors R4 and R9.
When assembling the integrated circuits in the heatsink, you must use insulated bushings to avoid electrical contact between the metal body
of the IC and the heatsink.
thermal pad
Suggested PCB mounting Brutus – bridged stereo ampli�er 2 x 170 Watts (300 + watts total) – click
in images for enlarge
TDA7294 Bridge stereo PCB bottom
TDA7294 Bridge stereo PCB layout
TDA7294 Bridge stereo PCB Silk top
About Brutus circuit assembly
The printed circuit board suggested for this assembly is single face, to facilitate mainly the life of the beginners … however if it is simple face
there comes Jumpers! Connect pieces of wire, interconnecting the dots, paying attention to the thickness of the jumpers at the power
connection points.
List of material to mount the ampli�er in bridged Brutus
Parts
Value
Resistors
R1, R2
27k
R3, R8
100k
R4, R9, R11, R13, R15, R16, R17,R19, R20, R22
22K
R5, R6, R7, R10
47k
R12, R14, R18, R21
47k
Capacitors
C1, C2, C17, C18
1µF /250V – Polyester Capacitor
C3, C6, C7, C8, C13, C14, C21, C22
22µF/50V – Electrolytic capacitor
C4, C5, C9, C10
10.000µF/50V – Electrolytic capacitor
C11, C12, C15 C16
100nF /100V – Ceramic Capacitor
C19, C20
220µF /50V – Electrolytic capacitor
Semiconductors
B1
Bridge rectifier VSIb2580, GSIB2580, D25xb60, GBJ2510, or equivalent
D1, D2
1N4148
IC1, IC2, IC3, IC4
TDA7294
Connectors
LIN
Terminal block connector 2 screws – Left Input
LOUT
Terminal block connector 2 screws – Left Output
RIN
Terminal block connector 2 screws – Right input
ROUT
Terminal block connector 2 screws – Right output
AC
Terminal block connector 2 screws – Transformer
Miscellaneous
Transformer
18018 at 26026 VAC /8A
Printed Circuit Board, Welding, Wires, Box, heatsink, etc.
Download the PDF files to mount stereo amplifier Bridge: Silk Screen, PCB, PCB component side, Silk screen, TDA7294 Eagle Library,
TDA7294 Datasheet
Download PDF
Mirror
Buy Diy kits TDA7294 in Aliexpress with free Shipping in the Worldwide.
Toni
http://xtronic.org/
Xtronic.org blog author. Electronics technician for the technical school of Brasilia Brazil. Interested in electronics, circuits and technology in general.