12V to +/- 12V

[Nickk2057]

what i want to do is make a circuit to run a amplifier circuit like a TDA2050. but i see that it uses a + and - volt rail with center common. how do i achieve this?

Thanks.
Nick

[linux-works]

for low current use, dc/dc converters would be the way.

most audio guys hate those, though.

otoh, the tripath or class-d you have in mind is already digital and extra dc/dc noise isn't going to hurt

best way is to go with a center tapped trafo.  ct goes to gnd and the 2 ends go to a bridge rect, which gives you the plus and minus rails.

you could also use 2 single ended FLOATING psu's and make a center tap; either at the ac level or at dc.

finally, you could use a diode trick to convert a single winding trafo output into dual rail dc output, but it adds twice the amount of hum (half wave config, iirc) and under current draw, the hum gets even worse.

[Dave]

Inverting switch mode power supply. Just set the frequency well above 20kHz and make sure that it never goes into pulse skipping mode.

[danadak]

You can run that part single supply, primary drawback is need for large
cap to DC isolate speaker from part. Datasheet shows this.

Just a thought.


Regards, Dana.

[Zero999]

What are your power output requirements?

If it's under a couple of watts you can use run the TDA2050 off a single 12V power supply.

Otherwise why not simply buy an IC designed for single 12V operation such as the TDA2005, LM4950, LM1896 etc?

http://www.ti.com/lit/ds/symlink/lm4950.pdf
http://www.kitsrus.com/pdf/tda2005.pdf
http://www.ti.com/lit/ds/symlink/lm1896.pdf

[uncle_bob]

Hi

The simple answer is : buy a +/- 12V supply and use that. They are out there and it's the simple solution.

A bit more complex: Spend $5 on a center tapped transformer (I just bought some at that price) and build a +/- 13 to 20V supply.

Either way, it will be cheaper than trying to fiddle with DC-DC converters and then quiet things down.

Bob

[Nickk2057]

well really a DC-DC converter is the only way to go with me cause i am making a suitcase boombox with aiwa speakers in it.

[jitter]

Might I suggest you look into something like this?

It's rated to output +/- 20..32 V, in the lowest setting comfortably within spec for the TDA2050.
Don't worry about the 350 W being overkill, they are most likely "Chinese Watts"  .

Edit:
You gotta love the Chinese for adding some important details:

Description:
- Main filter capacitor adopts imported chemical uf / 50 v * 2, 3300 in voltage up to 65 v, the other capacitor adopt Taiwan famous brand

Yeah right, Taiwan famous brand... 
What's that then, CrapXon?