Method for preserving charges on a cap at the output of a regulator

Abstract

The present invention includes a circuit to maintain a constant voltage on a storage element such as a capacitor at the output of a regulator during an emergency power condition. It includes a detector to detect the emergency condition and to generate a fault signal in response to the emergency condition, a one-shot time delay circuit to delay the enabling of a regulator in response to the fault signal, and a second delay unit to delay the enabling of the load of a regulator to accommodate the non-zero recovery time of a regulator. These two time delay units are able to bypass the noisy switching on the fault signal so that the maintained voltage on the storage capacitor will not droop and can be reliably used for such purposes as head retract and spindle brake under a noisy power emergency situation.

Dependencies are inferred from the claim text.