The absolute max allowed supply voltages for the

A full-wave power supply uses a center-tapped transformer and a bridge rectifier. For plus and minus 18VDC when the mains is 10% high and the amplifier has no load then the loaded DC with a normal mains voltage is about 16.2VDC.

A transformer that has a 24V center-tapped winding produces a rectified and filtered plus and minus 16VDC. it will be about plus and minus 18VDC with no load and will be plus and minus 19.8V with the mains voltage 10% high and no load.

It's about distortion here?

 

When you said "main term" maybe you were talking about the mains AC voltage.
I discussed that it might be 10% high and you don't want it to be more than the recommended max supply voltage of plus and minus 18V (a total of 36V). When the AC mains voltage is normal and the amp is loaded then the supply to the TDA2030A amp is about plus and minus 16.2V.

The graphs on the datasheet show the amount of distortion at various supply voltages and output powers.

 

I had placed the components on the test board and I have problems.

My TDA2030A is overheating extremly quiqly. In one minute it is verry warm and I must stop the supply voltage on the circuit and at the output loudspeaker it's hearing just a buzzing without any sound.

I don't have a filtering capacitor at the redressing diodes circuit and I had placed an 100k resistor for R5 instead 4.7k.

Any helping opinion?

Thanks.

 

You forgot to say how much is your supply voltage.
You also forgot to say if you used the recommended pcb design in the datasheet.

Which "filtering capacitor" did you not install? Maybe it is the important one that prevents oscillation.

R5 at 100k simply allows an extended high frequency response.

 

I had placed the components on the test board and I have problems.

My TDA2030A is overheating extremly quiqly. In one minute it is verry warm and I must stop the supply voltage on the circuit and at the output loudspeaker it's hearing just a buzzing without any sound.

I don't have a filtering capacitor at the redressing diodes circuit and I had placed an 100k resistor for R5 instead 4.7k.

Any helping opinion?

Thanks.

Your expression "redressing diodes" sounds ominously similar to the French expression for a power supply rectifier.

A substantial reservoir capacitor is obligatory after the power rectifier, as otherwise the DC supply will not be at all smooth, and you will indeed get a loud hum in the speaker.

 

My supply voltage it's made from an 12 0 12 V transformer at 1A and a bridge rectifier.

I have used the schemathic from the TDA2030's datasheet, named single supply amplifier, I think that it's all right.

I haven't install the filtering capacitor for the rectifier bridge.

I have a 2200uF capacitor, I used it for filtering at the rectifier bridge and the result was the same.

But why the TDA is burning so quiqly making the circuit unusable?

 

Operating the power supply with no smoothing may have damaged the IC. You may of course have other problems, such as faulty components, or wrong connections. Unfortunately, by now the IC may be damaged and you may need to get a new one.

First though you need to be as sure as possible that there are no other problems. You should post the power supply circuit you are using: there has been mention of a dual voltage supply, but your main schematic shows a single supply version. You need to be clear about what you are using.

Finally, have you fitted the IC with a suitable heat sink? This is necessary for a power amplifier of this kind. See spec. sheet for details. http://www.st.com/stonline/books/pdf/docs/1458.pdf

 

You changed all the resistor and capacitor designation numbers on your schematic and pcb so you are confusing everybody.

I looked at the R5 high frequency filter on the datasheet but your R5 is the feedback resistor to ground. It must not be increased from 4.7k to 100k because then the amplifier will have a gain of 0dB. The datasheet says that the gain must be higher than 24dB which is is 16 times. So of course it will oscillate at a high frequency.

Your pcb design uses skinny little conductors but the design in the datasheet has very wide conductors that have very low series inductance and very low resistance.

 

You changed all the resistor and capacitor designation numbers on your schematic and pcb so you are confusing everybody.

Let's look back and let's remind some things.

This schematic is taken from datasheet:



After this schematic I made it this edited version in my editing program:


And after this edited schematic I have made thisPCB layout schematic:




So I don't know where you say where I have changed the designation names for resistors and capacitors since in the datasheet I don't have them with notation. ( first drawing is taken from datasheetand it is the single supply amplifier example).

I have attachet the datashe for tda2030A

I looked at the R5 high frequency filter on the datasheet but your R5 is the feedback resistor to ground. It must not be increased from 4.7k to 100k because then the amplifier will have a gain of 0dB. The datasheet says that the gain must be higher than 24dB which is is 16 times. So of course it will oscillate at a high frequency.

If I am not to lasy, tell me please how you are calculating the amplifier gain depending by this resistance.
Because the closer value for the 4.7K resistor that I have now is 2.7k. I have a chance if I put this resistor?

Your pcb design uses skinny little conductors but the design in the datasheet has very wide conductors that have very low series inductance and very low resistance.

Isn't it that the larger the conductor it is, the inductance and resistance are higher?

 

Let's look back and let's remind some things.

This schematic is taken from datasheet: *****

So I don't know where you say where I have changed the designation names for resistors and capacitors since in the datasheet I don't have them with notation. ( first drawing is taken from datasheetand it is the single supply amplifier example).

In the first couple of pages of this thread we talked about a TDA2030A amplifier using a plus and minus 16V supply so its output power is 12W into 8 ohms.
But now you have a single 16V supply so the output power is only about 2.3W.

If I am not to lazy, tell me please how you are calculating the amplifier gain depending by this resistance.

The gain of a non-inverting opamp and this power amp is (R2/R1) plus 1. With the 100k and 4.7k on the datasheet then the gain is (100/4.7) + 1= 22.3. You changed the 4.7k to 100k so your gain was 1 which was too low.

Because the closer value for the 4.7K resistor that I have now is 2.7k. I have a chance if I put this resistor?

2.7k will boost the gain and cut high frequencies and cut low frequencies.
Use the standard value of 4.7k.

Isn't it that the larger the conductor it is, the inductance and resistance are higher?

Of course not.

 

In the first couple of pages of this thread we talked about a TDA2030A amplifier using a plus and minus 16V supply so its output power is 12W into 8 ohms.
But now you have a single 16V supply so the output power is only about 2.3W.

I have a question about the output power.
The output power is the power between the speaker treminals, right?

And by the formula: P=U*U/R for +/-16V= 32VDC and 8ohms the formula is 32*32/8=128W, why this formula is not applicabe here?

How do you got to the result of 2.3W at 16V single supply and 4ohm resistance?

Can I go further with my project, and I so, what are the most important guidelines.

If is posible I want to make less components changes because I find them verry difficult.

 

I have a question about the output power.
The output power is the power between the speaker treminals, right?

No.
The output power is the RMS output voltage squared and divided by the speaker impedance.
The p-p output is not the supply voltage, it is less due to losses. So with a 32V supply, the p-p output into 8 ohms is about 27.6V p-p which is 9.8V RMS which produces 12W.

And by the formula: P=U*U/R for +/-16V= 32VDC and 8ohms the formula is 32*32/8=128W, why this formula is not applicable here?

That makes peak-to-peak instantaneous Whats, not continuous Watts.
With a 32V supply, the peak-to-peak voltage is not 32V, it is about 27.6V. Then the RMS voltage is only 9.8v, not 32V.
Some cheap amplifier and speaker manufacturers rate with Whats instead of real Watts because they think average Joe Blow is stupid.

How do you got to the result of 2.3W at 16V single supply and 4ohm resistance?

The datasheet does not show output power on the graphs when the supply is less than 24v so I made an experienced guess.

Wih an 8 ohm load and a 16Vsupply, the p-p output voltage is about 12.1v then the RMS voltage is 4.28v then the power is 2.3W. the power into 4 ohms is higher because the current is higher but it is not double because the losses are increased a little. It is about 4W into 4 ohms.

 

A transformer that has a 24V center-tapped winding produces a rectified and filtered plus and minus 16VDC. it will be about plus and minus 18VDC with no load and will be plus and minus 19.8V with the mains voltage 10% high and no load.

Please post a link or explain to me how can be calculated the rectified and filtered voltage, because I don't get why for a 24V center taped transformer the produced voltage is plus minus 16VDC.

And further, how do you get the plus and minus 18VDC with no load?

 

Each half of the 24V center-tapped winding has 12V RMS. It has a peak voltage that is 1.414 times higher at +16.97V.
The rectifiers conduct a very high current for a short duration each half-cycle so they have a voltage drop of 1V and charge the filter capacitor to +15.97V.

The transformer has resistance that drops the voltage when there is a load. The voltage is rated at full load. Then when there is no load there is no voltage drop so the voltage is higher at +18V or more.

 

So, I have understood right?

 

So, I have understood right?

Your attachment doesn't work maybe because it is a BMP file instead of a PNG file.

 

I can see your circuit, but it will not give two supplies related to ground in its present form. The circuit shows a bridge (Graetz) rectifier feeding a single reservoir capacitor. This effectively gives a single supply of about 32V.

To obtain two supplies each side of ground, you require two reservoir capacitors, one connected from the bridge positive output to the transformer tapping, and the other connected from the transformer tapping to the to the bridge negative output.

Edit: I have just noticed that you have also labelled the output polarity from the rectifier the wrong way around.

This is serious - if you connect the capacitor and the IC like that they will be ruined, and the capacitor might even burst.

 

The power supply should look something like this:

Then use a circuit like the one show in Fig. 14 on Page 7 of the PDF. A suitable copper pattern is shown in Fig. 15 on Page 7. Be sure to use a sufficient heat sink. The TDA2030 package itself can only dissipate about 500mw before going into thermal shutdown.

If this is too much, I would suggest starting with an LM380 and a 9v battery supply.

 

@ BillO
Close, but no cigar. The +16V reservoir capacitor is backwards. Could you possibly re-post with this corrected - bear in mind that the OP seems to be at sea with this and is likely to have a capacitor accident.

 

I have posted a .PNG, I hope It is visible now.

The schematic is quote for:

Each half of the 24V center-tapped winding has 12V RMS. It has a peak voltage that is 1.414 times higher at +16.97V.
The rectifiers conduct a very high current for a short duration each half-cycle so they have a voltage drop of 1V and charge the filter capacitor to +15.97V.

The transformer has resistance that drops the voltage when there is a load. The voltage is rated at full load. Then when there is no load there is no voltage drop so the voltage is higher at +18V or more.

I'm interested by the calculating ideea not by conections.