Abstract: Apparatus for detecting series arcs and output load faults in high frequency luminous tube power supplies and ballasts including wideband ringing and detector circuits for collecting the intense high frequency, pre-plasma noise energy associated with the initial avalanche phase of high frequency arc formation and a transient suppressor for delaying the triggering of power supply shut-down for up to the duration of the arc avalanche phase. Plural detectors for increased sensitivity and reliability over a variety of arc locations may be employed. Dual purpose detector input probes serve as over-voltage corona generators.

Abstract: A high frequency power supply for distributed luminous tube signage including a master power unit and one or more slave units. The master unit includes a digital oscillator, controller, and electronic switches to induce a switched high frequency waveform across the primary of an output transformer. This waveform is preferably of a non-symmetrical variety to minimize neon bubble formation and mercury gas migration. The output transformer includes one or more low voltage ancillary power outputs for interconnection through appropriate twisted pairs or other transmission medium to the slave units. A high voltage secondary for direct luminous tube connection may also be provided. Various slave unit topologies are contemplated including remote or moving luminous tube segments; electronic controllers and sequencers, and motors.