Switch your entire installation On and Off with a simple push button.
A small circuit creates a latching switch that handles 25 - 100A !
(Includes explanation of PNP MOSFETs)
Really great write up! Thank you!
Very nice info @Juergen_Bruegl . Thank you for putting this together!
Very nice, I have plans for this…
Can I ask, what’s the quiescent current? Adafruit list 0.5 uA for theirs, is it of that order?
Yep, just like that - BUT you have to add the quiescent current of the ‘idle’ power supply: Eddy Current losses - sorry, that’s usually in the mA range, depending how >green< your 5V brick is 
Simple advice: pull the plug over night
Warning: only click on that link if you are really into that stuff 
been there - didn’t really like it, but had to
http://www.nptel.ac.in/courses/108105053/pdf/L-22(TB)(ET)%20((EE)NPTEL).pdf
a bit simpler but still… http://www.electrical4u.com/hysteresis-eddy-current-iron-or-core-losses-and-copper-loss-in-transformer/
p.s. your Mitochondrion gets ++++++++!
Cheers.
I am mostly interested in battery powered stuff, where I want to be able to leave it for weeks without the battery going flat. MicroAmps of drain is similar to the batterys’ self-discharge, so that’s all I need.
just updated the Wiki with better schematics and breadboard designs
Fantastic! Super useful.
@Mark_Kriegsman @Jez_Weston have you thought of the ‘easter-egg’?
Attach an Arduino digital pin to the switch:
You can get on your neighbour’s nerves and when the code calls EVERY_N_HOURS it switches all off while you are already sound asleep.
Or when the Arduino reads the Lithium voltage < 3.5V it prevents a (dangerous) deep discharge.