120VAC. Drop out is usually around 100VAC (maybe lower 90VAC)? 100VAC = ~ 140VDC which is well above the SELV requirement so that wouldn't work. But maybe you can work around the SELV requirement. Heck 120VAC is managed. Anyway, theoretically, you could run your PC and any like devices off of 140VDC. I might be a reliability hit to the bridge since you are only using one branch.
Modern switching power supplies might work with dc in, but anything transformer based, nada, must have AC.