Fault-current limiter for high power electrical transmission...

Fault-powered power supply

Faulted circuit indicator apparatus with transmission line...

Faulted phase selector for single pole tripping and...

Field ground fault detector and field ground fault relay for...

Field overvoltage protecting apparatus for synchronous machine

Filter capacitor charging circuit

Filter input protection

Filter using zno arresters as small capacitors in normal...

Five pin protector module for telephone circuits

Flameproof apparatus using non-grounded energy-limiting barrier

Flasher circuit with outage indication

Floating negative automatic grounding switch

Flow responsive time delay pump motor control logic

Food heating safety device

Four-pole to three-pole bussing for a network protector

Frequency relay for use in the protection of electric power...

Frequency selective transient voltage protector

Fuel burner ignition system

Fuel burner safety control circuit