I'm trying to design a circuit that will power my 12V LEDs. The battery should be 12V and up to 14V when charging. I would like to route it through an LDO voltage regulator when the battery is charging and just pass through the battery directly to the LEDs when it's below 13V (as the LDO won't operate below 13V).
I looked at buck boost converters and couldn't find anything that looked helpful, and I didn't want to waste the power in doing a boost then buck converter. Is this schematic feasible? Below 13V, the JFET just stays on and passes power to the LEDs. 13V or more, the zener diode allows power to the LDO, which then passes 12V or so to the N-Channel JFET gate, turning off the JFET.
EDIT: I see that my poor schematic software is causing a lot of confusion. Fritzring does not have the parts I was trying to render. I am NOT using an LD33, but rather a typical 12V out, 2Amp load LDO voltage regulator. Here's the datasheet for the KA278R12C: http://www.mouser.com/ds/2/308/KA278R12C-1120707.pdf. This is not for a vehicle, but rather some indoor lighting hooked up to a battery.