yeah I've been considering a crowbar. It seems a bit brutal. I suppose you get instant feedback that somethings wrong (gadget wont turn on) and it doesn't 'hide' the problem initially, like shunt zeners would.EATyourGUITAR wrote: ↑Tue Feb 09, 2021 5:05 pmIf your 5.6v zeners are shunts then you need to consider there is a TDP and current limit before they pop. Then you would have no protection as a result of going over voltage. Do an internet search for power supply crowbar circuit. But this may not be needed if your 5v DC supply has some over voltage protection or some very predictable failure mode of catch fire and turn off.
The problem I was trying to solve was overvoltage/spikes from the correct adapter. The diodes I've specced have 1W power dissipation, with 2 in parallel which should allow for a volt or so over for extended periods.
Now you're making me think about it, I will put a crowbar in. I am the end-user, so best make it fairly robust