When current drawn exceeds the rating of the PSU, the protection circuit will be triggered to protect the unit against overload or over-current.
Protections of overload or over-current can be divided into several forms:
FOLDBACK CURRENT LIMITING
Output current decreases about 20% of rated current, shown as curve (a) in the figure below.
CONSTANT CURRENT LIMITING
Output current remains at a constant level and within the specified range while the output voltage drops to a lower level, shown as curve (b) in the figure below.
Output power remains constant. As output load increases, output voltage decreases in proportion, shown as curve (c) in the figure below.
HICCUP CURRENT LIMITING
Output voltage and current keep pulsing ON and OFF repeatedly when protection is activated. The unit automatically recovers when faulty condition is removed.
Output voltage and current are cut off when output load reaches protection range.
Auto Recovery: PSU recovers automatically after faulty condition is removed.
Re-power on: PSU restarts by manual AC re-power on after faulty condition is removed.
Note：Please do not operate PSU in over-current or short-circuit condition for a long period of time to prevent a shorten lifespan or damaging the PSU. Protection mode of some of the products combines with different types of the forms mentioned, such as constant current limiting and shutdown.