How does the overload behaviour of power supplies work?

All PULS power supplies have outputs that are overload-proof, short-circuit-proof and no-load-proof. No external fuse is required on the output to protect the power supply. Switch-mode power supplies have an electronic system that restricts the output current in the event of an overload. If the maximum current is reached, the power supply automatically switches from voltage regulation mode to current regulation mode.

Current regulation mode has the following variants:

• Fold-back characteristic:
  In this case the current reduces in relation to the extent of the overload. This behaviour is not suitable for starting heavy loads. It is used primarily in linear regulated power supplies.
• Straight or U/I characteristic:
  In this case the current remains relatively constant in the event of an overload.
• Fold-forward characteristic:
  This is considered to be the least problematic overload behaviour, but it does come with the risk of a high short-circuit current.
• Hiccup-mode:
  In the event of an overload or short circuit, the power supply switches off and makes periodic attempts to restart until the fault is rectified. See “Hiccup-mode”.
• HiccupPLUS-mode:
  A combination of Hiccup-mode and the fold-forward characteristic which was developed by PULS and does not overload the wires in the event of a short circuit. See “HiccupPLUS-mode”.