Guys and gals
I am putting a system together and was reviewing the schematics when I suddenly realised I had a reverse bias situation on my hands.
The attached pdf shows the charger control cct. This allows me to switch the battery charger to the 12v battery, if the solar panel doesn't supply enough power, during the winter, for example. The battery charger is auto sense so it selects 6v or 12v O/P as appropriate.
This means that U1 has 6v on the D and either 6v or 12v on the S, but U2 can have 12v on the drain and 6v on the S. BAD!!!
To isolate I am going to insert a Schottky diode into the D of U2.
Question: should I include a pulldown between the D and the Schottky?
Edit: Before any one jumps on my head, I know the Fan Control signals are inverted. I've amended it at my end.
Shed_Solar_System_Mega_Rev1.pdf (8.96 KB)