Hour Meter & Mains Signal

[Docara]

Hello Everyone,

Just a couple of questions for a narrowboat based project with shore hook-up and on-board battery banks.

1. I need to implement an 'Hour Meter' when an engine is running. What method on the uC side could I best use to accomplish this especially as EEPROMs have a finite read write capability?

2. I would like a non contact and (ideally) a non transformer based mains (UK) power signal and without breaking the incoming feed wire, which is self powered but gives a signal to a uC.


For 1. I'm thinking a small battery back for some RAM could be the way forward which only writes to EEPROM when the mains power supply fails and the on-board battery gets switched off due to discharge - thoughts. My initial thoughts was to use either a GSM module / Rugby Clock signal for the time base or would an on-board interrupt timer be sufficient - your thoughts

For 2. I've been trying to find some data on a CT transformers or winding on a ferrite core but can't find anything - especially a circuit with component values - any pointers

Thanks
Matt

[Steve001]

Hi Matt

I would use a RTC maxim do quite a range there is a V7 component also
https://www.flowcode.co.uk/wikiv7/index. ... _(Storage)

for a battery back up solution have you seen this ?

viewtopic.php?f=7&t=17713

what do you need to know about current transformers ?

Steve

:edit

some good info here

https://en.wikipedia.org/wiki/Current_transformer