geoffr
Posts: 89
Joined: Wed Aug 22, 2012 11:25 am
Location: Melbourne, VIC

Pi Zero power consumption after shutdown

Fri Jun 03, 2016 12:50 pm

I was wondering if anyone has measured the current through a Pi Zero after it has shut down (i.e. power applied but system shut down).

I am busy looking at building an on-off switch to control the power supply to the Pi. If I can't get its current draw below that of a Pi after shutdown, then I need to rethink whether I bother cutting the power to the Pi on shutdown or rather just pulse the reset jumper to get it to boot again.

btidey
Posts: 1636
Joined: Sun Feb 17, 2013 6:51 pm

Re: Pi Zero power consumption after shutdown

Fri Jun 03, 2016 7:34 pm

Tested on a first gen Zero (no camera connector) but I don't think that makes any difference if no camera is connected.

Start up Zero with micro hub with LAN interface plugged in (powered from Zero). Settles down to 180mA (idle)

Shutdown Zero hub still plugged in goes down to 45mA

Hub is drawing approximately 20mA so I think the Zero is drawing about 25mA in shutdown.

One should be able to make a power switch that draws a very low amount when off.

geoffr
Posts: 89
Joined: Wed Aug 22, 2012 11:25 am
Location: Melbourne, VIC

Re: Pi Zero power consumption after shutdown

Fri Jun 03, 2016 9:16 pm

btidey wrote:Tested on a first gen Zero (no camera connector) but I don't think that makes any difference if no camera is connected.

Start up Zero with micro hub with LAN interface plugged in (powered from Zero). Settles down to 180mA (idle)

Shutdown Zero hub still plugged in goes down to 45mA

Hub is drawing approximately 20mA so I think the Zero is drawing about 25mA in shutdown.

One should be able to make a power switch that draws a very low amount when off.
Thanks. That saves me the effort of measuring that bit! I still need to do a bit of work on reducing the current flow through the input switch, as it should be possible to get it down to a really negligible level. It looks like my current design is stabilising somewhere just above 0.1mA. But I still have some problems I need to resolve.

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