As you can see that the project build is very simple and the number of components needed to make this are very minimal and can very easily be available at your local electronics store or laying around in you workbench!
the 8002 amplifier is an 8 pin IC available in SMD package and so making the circuit on a veroboard is a bit of a challenge. i decided to make the circuit layout and then generated the necessary gerber files so that the circuit can be fabricated easily.
Here I have attached the schematic diagram and my PCB layout in case you want to use the same.
Here is the datasheet of the IC for easy reference:
After designing the circuit , exporting the Gerber files and generating the necessary files for the CNC machine, it was finally time to fabricate the PCB using the isolation routing technique.
I was lucky to have a CNC machine which made my work very easy and I got the PCB real quick. You can always make your own PCB and make them by etching process of order them from a professional manufacturing house or even order them online nowadays.
I made 2 identical circuit boards in case I messed up the soldering process because soldering SMD components is always a challenge and we need to make sure the any unwanted shorts or improper soldering is avoided.
I have added the clips of the CNC milling in action in the tutorial video below. Make sure to check it out for more details!
The first step is to solder the IC in place making sure to avoid solder joints between adjacent pins or any other traces.We can then move on to soldering the rest of the through hole components in place making sure of the values.
After all the soldering job has been done, it is important to make sure that our circuit is error free. To do so we can use a multimeter in continuity mode and test out all the valid tracks and make sure of proper connectivity. Any shorts must be rectified by removing excess solder at the points and cleaning them thoroughly in order to remove impurities and residual flux.
As per the datasheet, the impedance of the speaker should be 3 ohms, 4 ohms or 8 ohms, using which we can get the power output as 3 Watts, 2.65 Watts and 1.8 Watts respectively. I had a few of them laying around and tested them with the amp and all of them work just fine.
In order to connect this module to power,audio source and speaker, I made these custom wires, one side of which was attached to female headers which fit into the header pins of the module. With this our setup is now complete and ready to be tested :)
This is my complete project. It is quite small and powerful at the same time. In comparison, it is almost the same form factor as an Indian 2 rupee coin. You can also power this circuit using a 3.7 V lithium ion battery as the IC supports a good range of operating voltage. Make sure not to exceed the max voltage recommended by the datasheet.
I hope you like this build!
Feel free to share your comments,feedback and doubts and do not forget to watch the video in the begining, and while you are there, consider subscribing to my channel as well.
Until next time :)