1-wire PSU

I've had flakey 5V power in my greenhouse for some time now.  I've tried various wall-warts of differing ampage but no go.   Finally I pulled power directly from the computer PSU this helped but it was still slightly below 5V  (4.86V).

So i built a 12V to 5V 3A convertor using LM7805 regulators in parallel.  Circuit diagram below.
Big thank you to Colin @ g1gsw with the help designing this.

Now, it is much better with 5.28V in the greenhouse (measured by a ds2438 Smart Battery Monitor).


Circuit diagram:

The finished convertor (not much is it?):

The circuit says 1R resistors but i found some 6W 0.86R ones in my box :)  Also i've not needed to add any heatsinks to the regs.