S

Safety Circuit     Any circuit (either the primary or the secondary) that is relied upon to reduce risks of electrical shock or fire (an interlock circuit, for example).

Safety Ground     A conductive path to earth that is designed to protect persons from electrical shock by shunting away any dangerous currents that might occur due to malfunction or accident.

Secondary     The output section of an isolated power supply which is isolated from the AC mains and specially designed for safety of personnel who might be working with power on the system.

Secondary Circuits     Secondary circuits are those circuits supplied from transformer output windings that are electrically separated from the input windings.

Sequencing     The technique of establishing a desired order of activating the outputs of a multiple output power supply.

Short Circuit Protection     In the event that the output is shorted, this circuit will protect the power supply by limiting the amount of current flowing through the short circuit.

Standby Current     The input current drawn by a power supply when shut down by a control input (remote inhibit) or under no load.

Surge     An abnormally high voltage lasting for a short period of time.

Switching Frequency     The rate at which the DC voltage is switched in a DC/DC converter or switching power supply.