Abstract: A transformer based power conditioner to provide high purity electrical power. Capacitor based low impedance filters may be connected in the transformer secondary for noise filtering. Surge suppressors may be connected from the start to the finish of the primary windings regardless of tap selection, to limit peak voltages due to transient electrical surges that reach the load. Filter performance can be improved as required by the end user, by cascading the filter circuits on the output lines.

Abstract: A surge suppressor circuit with imminent failure detection and self-maintenance capability. The circuit includes at least two surge suppressor elements. The first suppressor element is initially actively connected to the circuit being protected and, as this suppressor element approaches failure, or after failure, the circuit switches out the used suppressor element and automatically activates a subsequent or backup suppressor element. At least one subsequent suppressor element is initially in a backup mode and is not conductively connected to the circuit being protected until the first suppressor element nears failure, begins to fail, or fails. Additional backup stages can be added as needed. Circuitry for detection or display of the status of the assembly can be included to give one or more feedback signals to personnel or to other equipment. Such feedback could be in the form of an analog signal or a digital signal.