Abstract: A half-connector body has lateral ears that fit in small notches in the ends of the side walls of a ballast can, preferably at the top. An end wall, if present, traps the ears longitudinally in the notches; resilience of that wall, and of its attachment to the can bottom, enhance tight longitudinal fit. The half connector (a receptacle) presses against, and partly protrudes through an orifice in, the end wall (if present). Outside the ballast, in a new fixture, a jack slides freely in the receptacle to make wiring-harness connections. The jack has a ratchet-like manually operable hook to secure the jack until manually released. Each contact or lead in either half connector is preferably provided with individual strain relief by permanent deformation (as for example using a die punch, without heating or plastic flow) of the connector wall inward, to displace material irreversibly around the wires.

Abstract: A half-connector body has lateral ears that fit in small notches in the ends of the side walls of a ballast can, preferably at the top. An end wall, if present, traps the ears longitudinally in the notches; resilience of that wall, and of its attachment to the can bottom, enhance tight longitudinal fit. The half connector (a receptacle) presses against, and partly protrudes through an orifice in, the end wall (if present). Outside the ballast, in a new fixture, a jack slides freely in the receptacle to make wiring-harness connections. The jack has a ratchet-like manually operable hook to secure the jack until manually released. Each contact or lead in either half connector is preferably provided with individual strain relief by permanent deformation (as for example using a die punch, without heating or plastic flow) of the connector wall inward, to displace material irreversibly around the wires.

Abstract: A filament switch for a rapid start fluorescent lamp disconnects or reduces through phase modulation the heating current to a plurality of lamp filaments to save power. The switch uses a trigger in series with a voltage sensitive element and an impedance element, the switch being responsive to the difference between a lamp starting voltage and a lamp sustaining voltage for determining when and for how long the filaments are heated.

Abstract: A ballast assembly has a thermal circuit protector with a resistor mounted in close proximity, for protecting multiple coils in a ballast assembly. The thermal circuit protector is included in the assembly, connected in series with a first coil. The resistor is connected in series with a second coil, with the resistor sized to produce sufficient heat during a high current draw condition to actuate a bimetallic switch within the adjacent protector, thereby interrupting power to the ballast assembly and preventing damage without requiring a second thermal circuit protector.

Abstract: A ballast assembly for a fluorescent lighting fixture includes a magnetic core, a primary winding and a secondary winding, both windings mounted on a central leg of the core, with a shunt disposed between the windings to prevent a flux generated by the primary winding from coupling with a flux generated by the secondary winding. The ballast further includes means for securing the shunt comprising a wall placed between the windings, with the wall having one or more structures formed integrally on the wall for engaging the shunt. The wall may comprise a flange of a bobbin, or be free standing. Using formed structures eliminates the need for winding tape around the shunts to provide an air gap between the sunt and the core. This assures long-term stability and reduces the potential for nuisance humming.

Abstract: A retention clip for retaining a thermal protection sensor in contact with a ballast transformer core is disclosed which includes a vertical support engageable with a ballast housing for minimizing lateral movement, and a horizontal support, internal with the vertical support and engageable with the transformer laminations. A retaining bracket, integral with the vertical and horizontal supports, is provided which includes a channel defined by oppositely disposed shoulders and, such that a thermal protecton sensor is easily disposable therein. The retaining bracket is angled relative to the transformer and may be contactable with a removable cover for driving the sensor into contact with the core. The bracket is preferably composed of a resilient material for spring loading upon insertion, urging the thermal protection sensor into initimate contact with the transformer and thereby assuring optimum thermal protection over the transformer's life.

Abstract: A fluorescent ballast assembly has a primary coil wound on a primary coil bobbin and a lag coil wound on a lag coil bobbin, each coil having wire starts, taps and finishes. A strip circuit board including a plurality of pin receiving holes and a plurality of wire insertion holes corresponding to the wire starts, tabs and finishes, is attached substantially perpendicular to and in contact with the bobbins. The strip circuit board has an insulating support with conductive strips attached thereto, preferably manufactured using automated equipment. Substituting a mechanically constructed and assembled strip circuit board for a printed circuit board eliminates the need for chemical plating or etching operations, reducing costs and easing assembly.

Abstract: The high D.C. voltage power supply device for the electrodes of an electrostatic ink mist prevention system in rotary printing machines has a conventional full-wave voltage doubling circuit consisting basically of a transformer, plug-in rectifiers, plug-in capacitors and plug-in bleeder resisters. Additional circuitry mounted on an interchangeable printed circuit board comprising exclusively standard solid state switching elements such as an integrated circuit for producing an output pulse when the line voltage goes through zero voltage, which is utilized for turning the high voltage on and off via an SCR firing circuit in addition to illuminating a pilot light via a triac firing circuit. The D.C. high voltage load current is sensed across a resistor, and a resistor potentiometer is provided for setting the high voltage current turn-off trip point. A timing device is provided for re-energizing the solid state circuitry after a preset time interval.