Hi all,
I'm glad to see that I'm not "alone" in this pursuit.
Grumpy_Mike,
The reason I said "imagine" is because the software I'm using doesn't have the components that I'd like to place in the circuit
Rokkit,
Your suggestion although really appropriate for the task at hand, is quite expensive, considering that we'd also need a transformer up to 30V AC, and compared to what I'm planning (assuming it will work). But yes, it is a real, tested and proven solution.
tkbyd (and everyone else),
Very good initiative. Thank you for that.
In the circuit I posted above, I'm removing the diodes from the ground line as suggested by Grumpy_Mike.
Where I say "instead of an LM7812, imagine a battery + charger", what I mean is using an L200C + battery.
Here's a good example I found after some "Googling": Sealed Lead-Acid Battery Charger Circuit
L200C: 2,50 EUR
3 resistors + 2 small capacitors: 1 EUR
I wouldn't know how much these cost in the U.S. Oh wait, but I do: i.e. mouser 3,40 USD
The reason why I was planning on using a 12V battery instead of 6V, was that it would not be a good idea to regulate from 6V to 5V (too little difference for the regulator to handle).
Sure I could apply a voltage divider, but I'm not that confident on supplying fluctuating voltage to the circuit.
Is someone able to confirm/deny my first assumption of all? Will the greater voltage supply "win" over the battery while there's Mains power? In practice not draining from the battery at all?
Either way, how would I block current flow entirely, once the voltage drops below a certain limit?
Because I don't want my circuit to fry or malfunction when that happens. And I certainly don't want to drain the battery dry because, as I'm sure you know, draining the battery below a certain level will ruin it for good.
These are my thoughts for the moment.
Sorry for not having posted a revised circuit by now; I'm lacking the knowledge and/or software for that.