devyani_13
Posts: 1
Joined: Thu May 31, 2018 11:00 am

external power supply

Thu May 31, 2018 11:07 am

i am using raspberry pi3 b+ now i want to power up my pi through GPIO pin 2 or 4 using LM2576,and it should also work with usb power supply from adapter. i want to know winch supply is currently used by pi,if both supplies are present i want to use only power from the LM2576

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Imperf3kt
Posts: 2389
Joined: Tue Jun 20, 2017 12:16 am
Location: Australia

Re: external power supply

Thu May 31, 2018 2:05 pm

Only ever connect one at a time. The Pi has no way of differentiating the two supplies and using both at the same time will damage one or both of your power supplies.
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drgeoff
Posts: 9346
Joined: Wed Jan 25, 2012 6:39 pm

Re: external power supply

Thu May 31, 2018 2:40 pm

It is good advice to only connect one power source at a time though the risk of damage to one or both is actually quite low.

pksato
Posts: 295
Joined: Fri Aug 03, 2012 5:25 pm
Location: Brazil

Re: external power supply

Fri Jun 01, 2018 5:43 pm

Hi,
Didoes can be used switch between two or more power sources.
Each power source have a diode in series.
The main power need voltage little bit high that others.
Use Schottky diodes (1N5820) with low voltage drop.

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