Abstract: A preferred embodiment of the present invention provides a ballast circuit, comprising three sections: an input power section that receives a line AC signal as an input and provides a DC signal as an output; a pre-regulator section that conditions the DC signal; and a lamp driver section that drives a gas discharge lamp load. The pre-regulator section includes a transformer with an input winding, an output winding, and a current sense winding. The input winding receives the DC signal provided by the input power section. The output winding is connected in a flyback configuration with a flyback blocking diode, a bulk storage capacitor, and an output terminal for the conditioned DC signal. The current sense winding generates a signal proportional to the level of the transformer current. The transformer current is controlled by a flyback switch. A resonant capacitor is connected between the flyback switch input and ground, the resonant capacitor and the transformer forming a resonant circuit.

Abstract: A general purpose logic chip may be replicated for use to construct both the arithmetic unit and the control sections of a computer or other digital data processing or logic circuitry. The chip includes a number of features which when taken together permits its use for a wide variety of data processing functions, including as noted above, the basic arithmetic logic unit and associated functions in addition to micro-operational code control functions. The chip includes a 4-bit arithmetic unit and four registers associated with the arithmetic unit for handling inputs or outputs to and from the arithmetic logic unit. Mode code terminals are provided to implement micro-program control logic circuitry permitting several of the chips to operate on "bytes" or sets of bits of long digital numbers in parallel, without additional circuitry.