I'm not familiar with the current requirements of the VFD, but the 555 solution is only ideal if the load never varies. The MC34063 is a regulator and will provide a stable output as load as the load is within its specs.
I'm not familiar with the current requirements of the VFD, but the 555 solution is only ideal if the load never varies. The MC34063 is a regulator and will provide a stable output as load as the load is within its specs.