He sat one evening with a book in his hands and a crazy idea came up. Column speakers have become boring. So I decided to collect an unusual column, not like everyone else. It can be taken in nature or used in the garage, in the country.
I found an old book in the barn. I definitely won’t read it, but it’s still going to work.
For homemade work you need a thick hardback book, in soft work with it will be extremely uncomfortable.
Speakers need a small diameter. I took the old ones from some tape recorder. I have 1 watt for 4 ohms. This size is not particularly powerful. I have enough of this power, I will not wind up the full volume.
I will use a 18650 Li-ion battery as the power supply. I have a used cell with a residual capacity of 2440 mAh. If the book is thick, then you can install two batteries. I will do so if I don’t have enough capacity for this item. It is better to use Li-pol, it is just suitable for this homemade product in thickness. I didn’t have it, I used Li-ion.
I will charge the battery with a controller from China. These modules are cheap. There are also controller boards with protection, but I have one, which I have. Please note, the protection board is longer.
Since I have a charge controller without protection (BMS), I’ll use a protection board from the battery of my mobile phone. Fortunately, they are available everywhere.
As an amplifier I will use a ready-made module from China. The module is assembled on a RAM8403 chip. The board provides 2 * 3 watts. I will adjust the volume directly from the playback device. There is no need for a volume control.
I’ll use such a switch. He took it off the PC power supply.
Making a column from a book
We turn to the manufacture of the column. First you need to mark out where the speakers will be installed. After that you can proceed to marking cutouts for all elements. I marked the holes for the speakers elementary. We divide the page in half and draw compasses with circles, cut it out with a knife on paper.
After cutting round holes for the speakers, I proceeded to cut niches for the remaining elements of the column. You need to cut it carefully. You need to clamp the pages together and cut. The main thing is not to forget to recline some of the pages, they will serve as the front panel. Under the switch you need to make a through hole. Also, pass-through is needed for the charge controller.
Solder all together. The circuit is very simple. Battery power is supplied to the amplifier board. Minus directly, plus through the switch. The wires from the charge controller go to the 18650 battery. The protection board is soldered to the battery. The output wires from the amplifier go to the speakers. 3.5 mm jack. soldered to the input of the amplifier. I brought it out under the seam of the book.
When you close the pages, everything looks something like this. We check the work and then proceed to further actions.
Now you need to glue the pages together. Glues with ordinary PVA glue. After smearing the pages, put the book under the press. The glue dries out pretty quickly. If you do not put a press, then the page warps and it becomes not beautiful.
The window with the charge controller had to be finalized. Cut a very large hole. Glued a piece of the page. Also, the connector stuck to a piece of plexiglass. When you connect the charger, the charge process is clearly visible.
Such a portable speaker I got. It plays quite loudly. If there is a thick book, then you can make a column on 4 speakers.
Good luck to everyone in the assembly.