TDA7294 + Power Transistors AMP (TDA7293 to come also)

Jump to Latest
#643
Here's the old version of 4" and 1' version of 5" (will have new design to hide screws under ring), 4" will also have oval port
 

Attachments

  • IMG_20180402_024720.jpg
    IMG_20180402_024720.jpg
    358.1 KB · Views: 961
#648
I am still pressed for time to even finish the Ali 7294 boards I bought (every time I leave them lying around for half a year I have to redo all my checking to see what errors the PCB has or what changes would work to get better low-end output...)

But I would love to see a schematic for the bridged TDA7294 setup!
I think I would manage to figure it out myself, but I prefer to make 'learning' mistakes with cheap stuff, not with obsolete 20 year old chips...
 
#650
See datasheet.

BRIDGE APPLICATION
Another application suggestion is the BRIDGE configuration, where two TDA7294 are used, as shown by the schematic diagram of figure 25. In this application, the value of the load must not be lower than 8 Ohm for dissipation and current capability reasons. A suitable field of application includes HI-FI/TV subwoofers realizations. The main advantages offered by this solution are:
- High power performances with limited supply voltage level.
- Considerably high output power even with high load values (i.e. 16 Ohm). The characteristics shown by figures 27 and 28, measured with loads respectively 8 Ohm and 16 Ohm. With Rl= 8 Ohm, Vs = ±25V the maximum output power obtainable is 150 W, while with Rl=16 Ohm, Vs = ±35V the maximum Pout is 170 W.

Circuit dynamic power amplifier with TDA7294 - bridge 180W or stereo 80W - Xtronic
 
Last edited:
#651
Did anyone do analyses or, even better, measurements with these setups? One might be afraid that the drop-in of the additional power devices might cause distortions.
Btw, you know that there are applications with additional power darlingtons BDX53 and BDX54 in either the TDA7293 and TDA7294 datasheets? I don't know if these are class G or H, though.
Best regards!
 
#653
Last edited:
#655
GB2405275A : The secondary amplifier includes inductances (L1, L2) for extending a switching off period of the secondary amplifier to smooth any switching discontinuity.

https://uk.farnell.com/murata/bl02r...17.511871610.1550072650-1056206696.1550072650

The BL02 series from Murata are radial leaded EMIFIL ferrite beads inductor to produce a high frequency loss for suppression of noise. These inductor type EMI suppression filters are designed to operate from several MHz to several GHz. They are widely used as general purpose noise suppression components to cope with relatively minor noise issues. EMIFIL Inductor type filters behave as inductors with small inductance at low frequencies, while they produce a resistance dominated impedance at high frequencies. When serially inserted into a noise transmission path, the resistance component absorbs and prevents the transmission of noise.


BL01/02/03 series are ferrite beads with lead wires to
produce a high frequency loss for suppression of
noise. Simple construction and easy-to-use, effective
for low impedance circuits such as power supplies and
grounds. Effective also for preventing overshoot and
undershoot of digital signal in clocks or the like,
and suppressing the higher harmonic wave. Suitable for
prevention of abnormal oscillation at high frequency
amplifying circuit.
 
Last edited:
#658
spameris said:
Hello,

can you help me please with bug in my circtuit, im trying to build something very similar as this amp in this topic. But all what i get is fully open Q3 in this circuit, and dc in speaker.

Shared album - Andris Drulle - Google Photos

Have a nice day.
Click to expand...

did you get it to work?, cause you got no feedback in that circuit you posted, check the original i posted here
 
You must log in or register to reply here.
Top Bottom