[arm-allstar] Notes on under voltage problem

[Doug Crompton]

The Pi3B+ has a more advanced power and monitoring system. If you get a low
voltage message it is probably worth looking into. The key here is under
voltage and while this could be due to an under current power supply it
does not mean that a "zillion" amp 5V power supply could not be under
voltage. You need to check the voltage at the board with a good digital
meter. Another important consideration is that the dynamic change in
current of the board when heavily processing vs. idling can vary greatly.
If the supply cannot handle these extremely fast current changes it could
signal an under voltage condition. The wall wart you used to power your Pi2
or Pi3B may not cut it for the 3B+ especially in turbo mode.

I have had good success so far with wall warts BUT I consider myself lucky.
I run 10+ Pi's with outlet strips full of wall warts. Ultimately this is
probably not the way to go as besides the fact they can cause power
problems they also emit a lot of RF noise. A better way would be to use the
12V to 5V 3A modules and run everything from a good 12V supply fusing the
12V input at each module. Here are a couple of examples. There are many to
choose from on Ebay.

https://www.ebay.com/p/Car-Buck-Converter-Step-down-Power-Supply-Voltage-Regulator-DC-12v-to-5v-3a-15w/19011441481

https://www.ebay.com/itm/SUPERNIGHT-DC-DC-12V-24V-to-5V-3A-15W-Converter-Step-Down-Power-Regulator-Module-/392044239513


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*