Another Buck converter. For start simulation close the up interruptor, start simulation and open inetrruptor. Voltimeter are in the load resistor resistor. Zener in transistor's base set voltage reference. When voltage go down reference, op-amp act as trigger. The zener in the output only is for acelerate simulation when interruptor is open and it is not un the real circuito I madre. Problema: vout is less in real world and a short-circuit has broken op-amp
