Buck Boost Converter circuit +12 V input voltage (10v. .25 there may be between)-13v as a favor from the (inverting) power 250mA optionally output voltage D2 zener diode changing can be increased or reduced (5v … 20v) circuit operating... Electronics Projects, Buck-Boost converter circuit 555 "555 timer circuits, dc dc converter circuit, power electronic projects, " Date 2014/06/21