diy 2.1 pc speaker

Audioguru

Joined Dec 20, 2007
11,251
The TDA7240A is an amplifier for car radios so it uses a single polarity supply.
The opamps in the crossover circuit can also use a single polarity supply if their inputs are biased at half the supply voltage.
 

Thread Starter

juggler73

Joined Apr 10, 2010
47
"The opamps in the crossover circuit can also use a single polarity supply if their inputs are biased at half the supply voltage"

i dont know how to do that :confused:
 

Audioguru

Joined Dec 20, 2007
11,251
An opamp with a dual-polarity supply has its inputs biased at 0V which is half the total supply voltage.
If you have a +12V supply then if you bias the opamp inputs at half the supply voltage (+6V) with two identical resistors and capacitor-couple the input, output and feedback grounding then any opamp will work.

In my sketch I show a non-inverting and inverting opamp with a dual-polarity supply and a single positive supply:
 

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Thread Starter

juggler73

Joined Apr 10, 2010
47
how do they relate to the opamp circuit i already have

The only thing with in and non verting is the output buffers

im so confused
 

R!f@@

Joined Apr 2, 2009
9,647
I think OP is now more confused then before on what he was about to do.
Hehehehe
 

Thread Starter

juggler73

Joined Apr 10, 2010
47
Thank you AudioGuru

im going to hopefully get this all into Proteus ISIS then ARES
 

Thread Starter

juggler73

Joined Apr 10, 2010
47
im having a bit of a problem with getting the schematic laid out.

i couldnt do it with proteus so i changed to Eagle, ive done the tl072,tl071 bit.
but i having a problem with the amplifiers because i cant find a library files for the TDA7240 and the TDA2030. does anyone have lbr files for these components.
ive tried there website but cant seem to find them.

any help would be great
 

Audioguru

Joined Dec 20, 2007
11,251
Schematics and pcb designs are in the datasheets for ther TDA7240A and TDA2030A amplifiers.
 

Thread Starter

juggler73

Joined Apr 10, 2010
47
i would like to make my own pcb from the schematics ive got which are not from any schematics from there datasheets.
 
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