At 12:16 PM 5/7/01 +1000, Ian Hynes wrote:
>PICers,
>
>I have this battery power supply that has a 12V gel battery in series
>with a 6V gel battery. The idea was to have a 12V & and 18V rail.
>(Could've been done better but i'm stuck with it for now.) OK, I'm
>sick of clipping the charger terminals onto each battery separately so
>I figured a clever(?) way to switch the batteries in series when
>on-load and in-parallel for charging whilst disconnecting the load
>device.

Why not charge at 18V? (more precisely, 2.25V x 9)
Adjustable regulator, 18VAC transformer, bridge, cap, couple resistors, and
a protection diode across the reg.



>Used a 4PDT switch. Seems to work too, at least the switching
>side of it.

You're lucky it's a "break before make" switch.
The other type exists, and it would have been briefly, spectacularly,
interesting.
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