I think this is a rather simple question.

I want to make an audio amplifier using a pair of TDA2003, but in stereo. I plan to use a 1A AC transformer that i built in school as the power supply, its output gives either 11+11v or 15+15v.

I looked for info on the web but found nothing on this subject. Any help will be appreciated.

This is the TDA2003 mono schematic.

Attached Images

circuito.gif (3.7 KB, 21 views)

 

Hi Riff Raff, and welcome to the forum!

I probably won't be the guy to give you your final answer but don't despair: there are many folks on this board who could do this kind of thing between breaths. I'm sure you'll get an answer.

That said, I didn't actually see a question anywhere in your post.

Are you looking for information on how to build the thing in stereo? AFAIK the answer is to build the mono version twice.

Are you looking for hints on the power supply design? Construction? Or what exactly is it you want to know?


Good luck,

Torben

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Curiosity was framed. Ignorance killed the cat.

 

Hi Riff Raff,

welcome to the forum, too.

You might choose either 2X11V or 2X15V for the supply transformer. Using 2X15V the rectified and smoothened DC must not exceed 18V. (1A is a bit low, but might suffice for room volume settings - repetitive peak current is 3.5A)

Please refer to the ST TDA2003 datasheet. Your schematic omits an extra 100µF electrolytic capacitor for supply bypass. This is extremely important to avoid oscillations of the amplifier and resultant overheating.

Also planning the circuit layout please follow the exact trace routing as given in the data sheet (page 6/10) to avoid any complications concerning oscillations.

And, of course (as already pointed out by Torben) for a stereo amplifier you must have two identical boards.

Special care must be taken of the output electronic capacitor (pin4 to speaker). It must be able to stand peaks up to 40V. Even supplied with 12V the peaks will exceed 25V in any case.

Driving the TDA2003 at it's maximum performance you should plan for a good heat sink (e.g. SK104) and good ventilation as well.

Regards

Boncuk

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Proper Planning Prevents Piss Poor Performance

 

Yeah, basically, i wanted to know how to do that.

The rectified 15v suppy does exceed 18v, so i think i should use the 11v output.

So, how do i connect the supply?

the first TDA2003 should be connected between the "most positive terminal" (don't know how to say that in english) and the ground, and the second to the most negative and the ground ?

In other words, something like this?

Attached Images

circuito.jpg (173.5 KB, 16 views)

 

Your TDA2003 on the bottom will blow up because its supply is connected with backwards polarity.
Your supply is plus and minus 11V but the TDA2003 schematic uses only a positive supply, not a negative supply. If your supply is plus and minus 5.5V then it cannot be used.

With only 11V for its AC supply, its DC is 13.5V at full output and output power at clipping into an 8 ohm speaker is only 2W. With a 4 ohm speaker its output power at clipping is only 3.5W.

If you have two 4 ohm speakers then the max continuous power supply power is 3.5W x 4= 14W. The max continuous power supply current is 14W/13.5V= 1.04A.

The datasheet has a pcb design that should be used.

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Uncle $crooge

 

Hi Riff Raff,

This simple power supply will meet your requirements. It is a full wave rectifier with the ground connected to the center tap of the transformer.
Instead of using 1N4002 you might refer to 1N4001.

Connect C3 and C5 directly to the IC pins, and also once again, refer to the data sheet PCB layout.

Boncuk

Attached Images

PWRSUPP.jpg (20.9 KB, 10 views)

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Proper Planning Prevents Piss Poor Performance

 

Hi Hans,

Shouldn't there be a junction where the net from pin 3 on IC1-LCH crosses the lowermost net?


Regards,

Torben

__________________
Curiosity was framed. Ignorance killed the cat.

 

Hi Torben,

very quick look!

Of course, there must a junction. Just happened in a rush. Nobody is perfect.

(Not even German combat pilots )

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Proper Planning Prevents Piss Poor Performance

 

Correction

Attached Images

PWRSUPP.jpg (21.8 KB, 7 views)

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Proper Planning Prevents Piss Poor Performance

 

As they say: "To err is human. To really foul things up requires a computer."


Torben

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Curiosity was framed. Ignorance killed the cat.

 

Hans,
Please save your schematic as a very clear GIF or PNG file type, instead of a very fuzzy JPG file type.

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Uncle $crooge

 

Thanks for the hint audioguru. I just suppose a *.gif is of poorer quality than a *.jpg.

I'v no software to cut off unnecessary stuff made with the screenshot captor, except for *.bmp and *.jpg

Using micrografx picture publisher (version 6.0). If you have a good suggestion I will do according to your desire.

Greets

Hans

P.S. When did you have your vision checked last?

__________________
Proper Planning Prevents Piss Poor Performance

 

Hi Hans,

GIFs were OK years ago, before PNG. They have support for only 256 colours in their index tables, though, so photos often look grainy. JPGs are good for most photos or other images with lots of shading and colour gradients. PNGs are probably the best for schematics and diagrams. For schematics, GIFs would have sharper images than JPGs.

There are some free image editing software packages around. I mostly use the GIMP (GNU Image Manipulation Program). There is a version for Windows here. It might be overkill for just cropping screenshots, though. It can read and write almost any image file format you can think of.


Torben

__________________
Curiosity was framed. Ignorance killed the cat.

 

Hi Torben,

just downloaded GIMP. It was amazingly quick today. Comared to my old wireless modem the new thing I purchased about a week ago is really fun:
14.1MB downloaded within 4:41 minutes.

The new thing plugs into a USB port and isn't much bigger than a memory stick. It's also wireless and first the company wouldn't sell the stick to me. I'm living 15km away from the receiver/transmitter station and they argued the max range is just 4km. I proved the opposite having a team of 10 company guys and girls around here. It's almost like high speed surfing I was used to in Germany.

I just hate to post entire screen shots since the real object will be smaller than desired. Nobody is interested in the taks bar withing a schematic.

Regards

Hans

__________________
Proper Planning Prevents Piss Poor Performance

 

I have an image on my screen then press the PRINT SCRN button which saves it.
Then I paste it into my viewer program ADCSee or Microsoft Paint then save it as a very clear PNG file type.

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Uncle $crooge