I built a LM2576 via this tutorial http://www.ti.com/lit/ds/snvs107c/snvs107c.pdf. I used LM2576-5.0 because I need at output 5V and here is 3A max, but at output I placed USB connector I used 2 pins ground and 5V and cable USB -> microUSB (Raspberry Pi 5V/900mA approximately) all is going correctly without trouble. LM2576s schematic have at input 12V battery, but I need power a Arduino too (I can power arduino with 12V or 5V/500ma), but here is my question. 1.Can I power Arduino from battery before LM2576s schematic? something like this http://prntscr.com/1zkx4x, or 2. I used to power Arduino from output from LM2576s and here will use no 1 USB connector but 2 USB connectors something like this http://www.sos.sk/?str=371&artnum=40942&name=assmann-usb-bu2a-a-usb-a-2p...In both cases is it any types of influencing current?...or which solution is better? At 2 USB connectors I only need 4 pins 2GND 2 +5V, but can I combine?..Thanks

 

#1=yes you could

#2= You should power the arduino via its power input jack.. Not via the USB jack. Leave the USB jack open for programming,serial connection,etc.. if needed.

Please try to add some spaces to your posts next time. Its all jumbled together and frankly a bit difficult to read.

 

Yes sorry you are right, but when I will power Arduino via power input jack I need more than 5V, but I have 12V battery so its a first choice, but Arduino get hottest because stabilizer. But when I will power from USB connector it will be fine and directly 5V and, when I need programming I unplugged Arduino from battery and put to PC. But 5V is jointly for Raspberry Pi and Arduino but different mA is that okay?..via 2-stairs USB connector