F QUER: digitally controlled amplifier

C digitally controlled amplifier

Author: Filippov. And, astana-ori@mail.ru
Posted 23.08.2011.
Powered by KotoRed .

All good health, like to congratulate the cat on his birthday and give him a small and interesting project. For me it is very important because this is my first and most important thing is made complete device (please do not kick).

Once there was an idea to make the amplifier is not very powerful for my S-90 and making a trial version I have come to the conclusion that it is necessary to make it comfortable to use with all kinds of buns and goodies, and then can not do without a controller (that way for a good reason and the passions hobbies) Well, it was decided to start with radiation controllers and options for its use. In the end, we have the fruit of six months of study, trials, errors, defects, counts and good devaysu which pleases me so that I have fulfilled my thoughts and ideas into reality (pleasant pleasure).

Let's begin.

Mega168 microcontroller is the brain of all that is in our devayse, he immediately executes all commands that we order it with a single encoder (nothing else to manage because the idea was as follows.)

Encoder, we can adjust the volume, go into the menu to change settings, turn off the sound, tune the radio, turn off and turn on the Amplifier (poor man I love him to torment).

As well, we have the famous 555 timer which we have entrusted pikat squeaker (variable resistor adjusted tone tweeter).

Display, and that it works as required, it displays the information (when you turn off the amplifier he's a turn off and turn on when you turn on).

Well continue our little excursion.

At the next board we have a lot of all, here we have for example have a lot of Multiple Connectors through them we connect 3 stereo channels (CON1 eg computer, TV, satellite receiver) is designed for the following columns (CON2) the rest are for connection to the control board.

TDA7439 is audioprotsesor which is controlled via a bus I2c (TWI) and changes the set of parameters:

adjust the volume.
selection of the input channel 1 to 4.
adjustment of the output channels, right, left.
High frequencies.
Mids.
Low frequencies.
Previous gain.
Reducing output signal (ATT).

LM358 for that to the controller properly and more accurately looms volume (VU meter, a sort of turned and much more interesting to look at him bathed on a spectrum analyzer), variable resistors set limit, so as not to spoil the controller. It works well on the TDA7439 is output (which can be for example prikoshatit equalizer) to them we are under rushed and now we have a signal from all four channels, and of the operational amplifier outputs to the channels we prikoshatim ADC controller and will read them and on the basis of these data to draw galloping lines.

JP3 connector is designed for radio module which I tore out of the burnt recorder SONY controlled via bus I2c (TWI).

Next we've got quite a bit here on the scheme we have left only the amplifier transistor and stabilizers that moves the cooler to lower the temperature (as it turned out, and to increase the small noise).

As a basis TDA7377 amplifier was taken from the original scheme of the datasheet and opto couples to disable (upravlyaetsya with the controller).

The fan is controlled by the controller (which he increased the rate with increasing volume after it was made a separate menu of its range since the amplifier does not have time to heat up and the buzz was increased. Now stands at a minimum and the temperature does not reach the mid-point).

Well, at the end of 7809 and 7805 Well, I think it makes no sense to explain why I ran across them here. It feeds all the goodness from the Chinese switching power supply to 12v 5A.

Now nemgo gallery ready amplifier for my recipe!