I have seen several online circuit diagrams for a DC to AC inverter. Commonly many inverters use a transformer to step up 12V to 120V. I understand that inverting from DC to AC requires additional components, and that the transformer only induces 12V to 120V, so it doesn't make AC out of DC (that is done by the rest of the inverter circuitry).
The question is, given a choice of any possible voltage into an inverter without a transformer, what voltage would result in the inverter producing 120V RMS naturally? Is it 170VDC?
So once again, in an inverter design without a transformer, what DC input voltage would result in 120VAC naturally?
Ultimately, what I am trying to determine is what is the most efficient design for a DC to AC inverter. If by inputting a specific voltage, one can omit the transformer normally found in a DC to AC inverter design, then that reduces the number of components in the design (and naturally increases efficiency since the transformer isn't 100% efficient).
However my question isn't intrinsically about simply being able to remove specific components (such as the transformer) from the design. I am looking for the most efficient design, with or without any specific componentry.
What would the (DC) input voltage for that DC to AC inverter design be?