Amplifier + car battery charger in one

Step 1: Step 1. Component List

Hello everyone, this is my first instructional and I hope you will like it. Original idea was to create amplifier that could be used in mine cottage at the Danube river, where there is not electricity and I'am moistly using power generator or car battery as a power source.

This charger is most simple charger without any current limiter and it should be used only on the old acid Pb batteries with capacity > 92 Amh, because you should not charge the battery with higher current than 1/10 of it nominal capacity ( e.g. 50 Amh battery should not be charged with current more than <=5A )

By disassembling some old car cd-player I found two TDA2005 which are perfect for this project, as a inspiration I have use this tutorial for creating PCB for amplifier

Thx : http://electronics-diy.com :)

It would be annoying if I repeated this tutorial, it is good tutorial and very well explained. PCB was made by etching method

Component list :

1. Transformer 230 V / 12 V - 10 A (for amplifier will be sufficient 5A )

2. Amplifier TDA2005

3. Diode bridge >10A ( I used 50A :) )

4. Capacitor > 50V min. 8000uF (or two 4000uF)

5. Knob

6. Gillette gift box :) (or something similar)

7. switch

8. Voltmeter

9. connectors (cinch, banana connector....)

10. Some wood for the box

11. Mesh for the top

12. small electronic parts (relays, IC 7803, IC msp430g, optocoupler, few resistors )

Step 2: Step 2. Schematic

Schematic is quite simple, primary winding of transformer are connected to 230VAC and secondary windings are connected on rectifier diode bridge (GREC) and capacitor. Basically I needed fast charging of battery and transformer is 10A so I have used 2 x 4000uF capacitors (50V). When you used capacitor for AC / DC conversion it is recomended to use capacitor of 1000uF per 1A.

Also I wanted to switch between at least two AUX inputs so I decide to make small pcb that will consist of two relais. I didnt want to complicate the front of the amplifier, and the pot that I have used ( it is from that same old car player) had push button on it, so I made a small program in TI energia (it could be used also on arduino) and used this push button for switching between two chanels.

Panel Voltmeter is connected directly on the 12 VDC (it is actually > 14VDC after AC/DC conversation) and I have added small switch so that it is powered on, only when it is needed

Step 3: Box

Design of the box was limited to the gift box that I have find lying around in my house. It is not very solid box so I had to make some wooden frame. Front panel is made from walnut board and painted with lacquer.

<p>Thanks for sharing :)</p>