I think there may be devices specified to use alternating current (AC) which can run supplied with direct current (DC) instead.
There are devices which depend on AC in some fundamental way, like a motor creating alternating magnet fields. These do not work on DC.
But other devices use DC internally, but are specified to run on AC. They convert the supply current to DC as the first step.
I would like to run a device that is specified to require alternating current using DC, because DC is easily available. The device seems to use a full bridge rectifier (consisting of four diodes) as the first step of using the supplied power.
I think for a device like this, DC should work. But if so, it is not clear to me which voltage to use, in relation to the specified AC voltage.
Do you think the case above would work? How to decide for which devices it works?