Abstract: A ballast assembly for a fluorescent lighting fixture has 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 the flux generated by the secondary winding. The ballast further includes a shunt retaining clip disposable between the windings, the clip including a essentially U-shaped wall having a pair of upright portions and a crossover portion, a bottom ledge attached to the crossover portion for accepting the shunt. A spring arm extends between the pair of upright wall portions of the U-shaped wall with the spring arm sized to resiliently engage a top surface of the central core leg.

Abstract: A wire bobbin (1) for use with inductive devices is disclosed having a central core (2) about which a wire is windable, with side walls (3) and (4) oppositely disposed about the core for retaining the wire thereon. A coil of wire, wound about the core, has a wire end (20) extending through at least one side wall. The side wall further includes a first channel (7) sized to retain a lead wire (21) therein, with the channel open at both ends. A second channel (13), which is preferably directly adjacent to the first channel, communicates through an open end (9) with the first channel. The lead wire is then inserted into the first channel, with a stripped end (22) extending into the second channel. The stripped end is combined with the magnet wire end, permanently joined, such as by dip soldering, and then bent into position within the second channel.

Abstract: A circuit is provided to speed up switching of a capacitively coupled power transistor driven with a signal provided from a pulse width modulator. The speed-up circuit is provided across a buffer amplifier which is in series circuit between the pulse width modulator and the coupling capacitor. The speed-up circuit includes a time delay circuit which is activated when the output of the amplifier goes low. The delay circuit is coupled to actuate a clamp circuit at a predetermined interval after activation. The clamp circuit is connected to the input of the amplifier and, upon actuation, pulls up the voltage at the input of the amplifier so that it is at a level intermediate the extreme values of the pulse width modulator output signal. In a preferred embodiment the timer is a series RC charging circuit and the clamp is a transistor with its base connected to the junction between the capacitor and the resistor.

Abstract: In a capacitor of the wound metallized dielectric type, a section of resistive material is provided on a film forming the metallized dielectric, and this resistive material extends across the film's entire width (the axial dimension of the capacitor). A metal contact for one of the capacitor plates is sprayed on either end of the capacitor so as to touch one end of the section of resistive material, thereby creating a resistive shunt across the plates formed on the metallized film. The section of resistive material is preferably carbon-loaded paper which is secured over an unmetallized area to the film used to make the capacitor. The paper projects beyond either lateral edge of the film so that spraying metal on the ends of the capacitor causes the ends of the paper to be connected to respective capacitor plates.