The table below summarises the plug types, voltage and frequency of electrical current in both Bulgaria and Korea, North.
|Plug Types||C, F||C|
|Frequency of electrical current||50Hz||50Hz|
In Bulgaria there's more than one plug type in use.
What type of plug does your appliance have?
No adaptor needed
Korea, North uses Socket Type C, which is the same as the plug type of your appliances from Bulgaria. You will not need an adaptor.
You will need this adaptor:
Socket Type F
(Bulgaria) to Plug Type C
The voltages found in Bulgaria (230V) and Korea, North (220V) are not exactly the same, but the difference is tolerable, so you should not need a transformer.
The frequency found in Bulgaria and Korea, North is exactly the same (50Hz). Timing devices and appliances that use motors will function as expected under this frequency.