Charging diagram question

[Goldstubble]

I'm confused about ShockSlayer's charging diagram:

What is the difference between the 7.2V AC adapter and the charging jack positive?

 

[samjc3]

the charging jack positive takes the power from the charger, whereas 7.2v ac adapter is used as an alternate power source to play the system on wall power. (the charger doesnt have enough juice to play and charge, except on really low power draw systems)

 

[Goldstubble]

Ah, I see. I don't have that alternate power source so what would the diagram for the DPDT switch be if I only need an off/charging mode?