The LA4440 microcircuit is a very attractive element for electronics because it has a simple switching circuit, low supply voltage and low cost of purchase. It can be used in stereo mode or bridged both channels to increase output power.
Now you will see how easy it is to make your own stereo system using such chips. The built-in player will be used as the sound source. It is good because it has an MP3 player with card readers and a USB socket, FM and bluetooth receiver.
Will need
- MP3 player with bluetooth -
- Microcircuit 2 pieces LA4440 -
- Resistor 680 Ohm - 2 pieces.
- Resistor 100 kOhm - 2 pieces.
- Capacitor 100 uF / 25 V - 6 pieces.
- Capacitor 47 uF / 25 V - 4 pieces.
- Potentiometer 50 kOhm - 2 pieces.
Making a stereo system with bluetooth
In the example, two microcircuits will be used, connected in mono bridge mode. Each to their own channel. The connection diagram, as well as the board, can be found in the datasheet.
We take a plastic base. Fasten the player with screws.
A piece of aluminum profile with pre-drilled holes for microcircuits is used as a radiator.
Be sure to lubricate the landing site with heat-conducting paste.
We screw the parts. We connect pins 3, 6, 8, 14 of each microcircuit. This will be the negative power bus.
Next, we connect the 11th pin of the microcircuits, this will be a plus.
We hang 100 uF capacitors, 3 on each microcircuit: on pins 5 and 6, 9 and 10, 13 and 12.
Next, between pins 1 and 7 there are two 47 µF capacitors in back-to-back series.
Solder the resistors. 680 Ohms to pin 3 and the middle of the capacitors. 100 kOhm to pin 2 - this will be the input.
We solder the pads to connect the speakers and power.
The sound will go to the input of the microcircuits through variable resistors.
Which will take the signal from the player.
Connect the player's power.
It will also be powered by a common voltage of 12 V.
All that remains is to supply power from a 12 V power source. Connect to the player via Bluetooth via a smartphone and enjoy the music.
Watch the video
There are even simpler microcircuits to connect - https://enn.washerhouse.com/3898-ochen-prostoy-moschnyy-usilitel-na-mikrosheme.html All you need is literally 2 capacitors. So be sure to check it out.
