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The first integrated circuit invented by the engeneer Jack S. Kilby1 (1923-2005) contained only a few transistors. Texas Instruments.

TDA7492p audio amplifier





TDA7492p bluetooth portable speaker

tda7492p bluetooth tutorial

We all like listen to music. In this tutorial we are going to see how to build ourselves a high quality bluetooth portable speaker. All we need is an old 50W speaker, the TDA7492p module and a bluetooth device to play the music. I'll use my android smartphone to play my own music.

This will be a quick, easy and really low cost tutorial. I've got my speaker case from an second hand store. The amplifier module is from eBay. I already has the bluetooth reciver module integrated. All we need are some wires, a 12V battery or higher, some connectors, push buttons and a charging module to charge the battery whithout openning the speaker case.




TDA7492p bluetooth module


tda7492p bluetooth tutorial

The TDA7492p is an audio amplifier. You could buy directly the chip and make your own circuit. But this module has already integrated a bluetooth module, all the used components in the amplifing process, output connectors and control buttons. All we need to to is supply 12V to 36A to it, connect an 8 ohm 50W speaker to each output and connect a bluetooth device to it. Be careful, there are identical models with just 20W or 25W output so keep that in mind while buying. I've bought mine from ebay with just 9 dollars, here is the link.

In the layout above you can see that the board has 5 control buttons. You could also use those to change the track or control the volume. There is a DIP 2 switches button. Combining the up/down position of each switch we could obtain 4 different filters for the output. In the layout above you can see each combination and the applied gain in each case.




Schematic


tda7492p bluetooth tutorial

I will use two 7.4 Li-po batteries connected in serie to obtain around 15 volts. Il drill the speaker case and add ane external connectro. To this connector I'll connect a DC step up module. In this way I'll apply a 12V input and I will be able to charge the 15V batteries. Using the potentiometer I'll set the module output voltage to 15V. To turn on and off the module I have used a toggle switch. Connect the TDA module output to the speaker and the circuit is ready.




Building the case

I will use an old 50W speaker. Open the front of the speaker and get out the speakers. Mine has 3, low, med and high. For the med it is recomanded to use a 10uF capacitor at the input. I'll make some holes in the speaker case and fit the audio amplifier module inside. I will also make some holes for the 5 buttons. Solder all the wires, the two batteries inside and the output of the amplifier to the speakers. Close the speaker front part. Add the toggle swith on the exterior of the speaker case to turn it on and off. The 12V plug will also be pn the exterior, in this way wa can charge the batteries without opening it.




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