tda 2003 general audio amplifier circuit

[shlomo1234]

Hi all,

In general, why we use high capacitor in the output (say 1000uF)
where in the input smaller one like 1-2.2uF. In both way we want to block the DC right?

Thank you

 

[BobK]

Hi, and welcome to E.P.

The size of the capacitor depends on the impedance of the circuit. A resistor and capacitor make a high pass filter. For audio, we want it to pass everything above about 20 Hz.

In the input, you might have a 10K input impedance, and the capacitor that would result in a 20 Hz corner frequency is 0.8uF. For an output with an 8Ω speaker, the capacitor is about 1000uF.

I calculated these using this on line calculator:

http://www.muzique.com/schem/filter.htm

Bob

 

[shlomo1234]

Thank you very much Bob !!

Also, the link helps a lot to understand (what i'v leared long time ago)

Thanks