Portable speakers for your phone
When you want to strengthen the sound of your device, whether it's a phone, a tablet. Turn the volume on all and the battery discharges the application. But it happens that the volume is not enough. At home, in the presence of sockets used columns. Outside the house, a portable speaker helps to cope with the problem of nutrition, but their prices are quite high. I decided to remake cheap speakers. The price of completion is low, and the result will suit many.Having examined, we see the simplest equipment. Transformer and amplifier board with volume control and power button. About the button there will be a separate conversation next.Unplug the mains transformer and power cord.We put aside, they will no longer be useful to us.Initially, I calculated the power from two 18650 Li-ion batteries. But due to the fact that the speakers were changing the dynamics by one watt (they were half a watt and quiet), had to use Li-polymer flat batteries. They are used, but the total capacity is more than enough.Our batteries will be charged using a charge controller from China. The controller is equipped with a deep discharge protection. On the board are marked B- / B +, they are connected to the rechargeable battery. OUT + / OUT-, the load is connected to them.A charge controller is mounted in the sole. We cut a window under the connector and file a board, the main thing is not to damage the tracks. The board is glued to a double-sided tape, for reliability, you can also fix it with thermal glue.Since the speakers had mains supply directly to the transformer, and from it to the diode bridge, this part is redone.We solder all diodes, 4 pieces.Power from the battery, more precisely from the charge controller board, soldered to the plus and minus the diode bridge. Also, the power supply will be switched by the column switch.We pre-solder our circuit with a canopy on the wires and check for operability.Flat batteries are fixed with a simple brace of copper wire with an insulating tube put on it. To control the process of charging the batteries, in the sole we make a hole opposite the LED display of the charge controller and fill with hot melt adhesive. Excess glue is cut off. We twist the speakers and connect the charger. Charges from any charger from a smartphone, tablet and micro USB output. The display is perfectly visible.