helpneeded in powe suppluy design

hi guys,
I have made an amplifier using tda 2050 ....can any one pls help me in designing power supply for the amplifier fpr the split supply version to get an output of 30watt at 4ohm load .....
here is the link for the datasheet where the circuit for split supply design is given....**broken link removed**

pls give me the ratings of transformer in in terms of amperes.....i was guessing a 25volt centre taped 2ampere transformer would be enough....

Look at the datasheet.

The peak current is 5A but you might be able to get away with less if you don't crank up the volume too much as the output filter capacitor will take the strain.

The maximum supply voltage is +/-25V.

What do you mean by a 25V centre tapped transformer?

Are you talking about 25V-0-25V which is really a centre tapped 50V transformer?

If so the output voltage will be too high, 35V, which would ruin the IC. You've forgotten that the DC output voltage is the square root of two times the rated output.

I would suggest a 15V-0-15V transformer which would give 20.5V.

Make the filter capacitors as large as you can, no smaller than 10,000:mu:F.

but what is meant by split supply design

thanks for ur time hero but can u pls tell me what is meant by split supply ...does that mean that I have to provide +15 and -15 to the ic...f you can pls help me with the schematic

Hi Nightcatz,
A split supply has positive and negative supplies. The TDA2050 needs about +19V and -19V for 30W output at clipping into 4 ohms.

Use a 30V center-tapped transformer, also called 15V-0V-15V. it should be rated at 1.5A to 2A for a mono 30W amplifier.The center-tap goes to the amplifier's ground. Use a rectifier bridge module and two filter 4700uF capacitors.

But the peak current is 5A, I would recommend much 2A, I would go for 3A minumum.

The 30W amplifier draws 60W from the supplies if the output is music, a sine-wave or a very badly clipped square-wave.
The filter capacitors supply the peak current and the transformer supplies the average current.

The amplifier won't be operated at 30W continuously, it produces music which has a low average level. So a 1.5A transformer will be fine unless it is tested at full output for a while then a 2A transformer should be used.