Sorry,
Background... system needs to switch to batteries when the AC fails. I have the battery charger (AL624), I have the transformer (which is a 16vac 20va) & the batteries.
I do not have a switch, at radio shack I found a 12 vac switch (but i do not remember which one).
the system will need to be tested monthly, (i was thinking of adding a toggle switch to do this, but that is after the system is working)
I know nothing of resistors, so I would not know what size o how many to get.
I know just enough to know to screw things up, or follow someone else explanation. I was hoping for help; however, I fear I maybe beyond help.