Abstract: A system for driving a load is disclosed comprising a programmable power supply for metering power directly to the load and a regulating element connected to the load and parallel with the programmable power supply for shunting excess power from the programmable power supply in response to a control signal in order to waveshape the power signal to the load. Sensing means are provided for sensing the power demands of the load and generating a control signal which is received by the programmable power supply. In response to the control signal, the programmable power supply meters more or less power to the load so that the power delivered directly to the load by the power supply approximately follows the power demand of the load as determined by the control signal.

Abstract: In an AC-to-DC converter, a switched inductor, in the form of a ringing-choke or flyback DC-to-DC power converter, is interposed between the AC line input rectifier and the DC storage capacitor. In accordance with the relationship Inductance/Time equals Voltage/Current the inductance and on-time of the switched inductor are held constant so that the instantaneous input voltage and current maintain a directly proportional relationship, thereby imparting a resistive characteristic to the input impedance--i.e., the input reactance vector is held to near zero rotation. Hence, the input power factor is held close to unity. Means are included for varying the values of the inductor and/or time in response to changing load requirements.

Abstract: A method and apparatus for detecting the end of charge of a battery includes the steps of periodically changing, for a predetermined time period, the magnitude of charging current to a battery or bank of batteries, during each such predeterimined period, measuring the voltage drop across the battery or batteries until a predetermined level is reached, and producing an "end of charge signal" in response to the predetermined level of voltage drop being attained.

Abstract: A power supply includes a plurality of transformers with individual primary windings, having one end connected in common, respectively, the transformers sharing a secondary winding; a switching network for (1) applying alternate polarity DC voltages to the commonly connected ends of the primary windings over each half-cycle of a clock signal, and relative to these commonly connected ends of the primary windings, (2) applying the same or opposite polarity DC voltages individually to the other ends of the primary windings, over each half-cycle of the clock signal, and in different combinations dependent upon the amplitude or level of a command signal at any given switching time, for producing a pulsed AC waveform in the secondary winding that is amplitude modulated by the command signal.

Abstract: A battery charging system including a plurality of transformers each having a primary winding, a secondary winding, and a tertiary windings, the primary windings being connected in series forming a "shared primary", a first switching network for connecting a DC voltage across the shared primary winding, in alternating polarity over successive half-cycles of a clock signal, for causing voltage pulses to be induced into the secondary and tertiary windings of the transformers, a second switching network responsive to the magnitude of primary current for shorting the same or different combinations of the tertiary windings, thereby shorting the associated transformers, over each half-cycle of a clock signal, for controlling the magnitude of charging current to the batteries, and a plurality of rectifiers for rectifying the AC voltages developed in each secondary winding, respectively, for providing charging current to the battery.

Abstract: A power supply for providing an output voltage amplitude modulated by a command signal, includes a rectifier for rectifying the command signal, a comparator network for comparing the instantaneous rectified level of the command signal with a plurality of predetermined reference voltages, for producing a plurality of phasing signals, respectively, for operating a switching network to (1) alternately and successively connect positive and negative polarity DC voltages to the one ends of a primary windings of a plurality of transformers, and to (2) connect either the positive or the negative DC voltage to the other ends of the primary windings in different combinations, over each half-cycle of a clock signal, for producing in a common secondary winding for the transformers the amplitude modulated output voltage. Another rectifier may be provided for rectifying the AC output voltage, for producing a DC output voltage amplitude modulated by the command signal.

Abstract: A method of producing an indicia transferring surface including affixing an inert material in the shape of indicia to a base sheet containing a curing inhibitor coating. A curable compound is placed on the surface of the base sheet in contact with the indicia shaped inert material and is allowed to cure. After a curing period, the curable compound is separated from the base sheet. The curable compound includes a cured portion and an uncured portion. The uncured portion is removed, leaving raised areas of the cured compound that were in contact with the indicia shaped inert material. The raised areas may then be used to transfer the impression of the indicia to another surface.

Abstract: A linear DC power supply provides high efficiency with substantially lower total capacitance than prior art linear DC power supplies. The power supply includes first and second input terminals, first and second output terminals, a center tap transformer, first and second capacitors, first and second charging circuits, and first and second discharging circuits. The center tap transformer has a primary connected to the first and second input terminals and has a secondary with first and second phase terminals and a center tap terminal which is connected to the second output terminal. The first charging circuit is connected to the secondary and the first capacitor to fully charge the first capacitor during a first portion of each cycle. Similarly, the second charging circuit is connected to the secondary for fully charging the second capacitor during a second portion of each cycle.

Abstract: A temperature control system controls operation of two heaters, such as the solution heater and dryer heater of a photographic processor. First and second temperature detectors sense temperature and provide first and second detector signals, which are compared with first and second reference ramp signals by first and second comparators. The comparators produce first and second inhibit signals, which prevent power from being supplied to the first and second heaters, respectively. A priority circuit prevents power from being supplied to the second heater if the first heater is receiving power.

Abstract: An optical character recognition device including means to define a scanning area which includes portions of a printed character to be scanned by a television camera, said camera scanning discrete points of said area arranged in spaced vertical paths, and including means to measure the optical density of the character portion encountered at each point and to assign a binary-coded numerical value to each point and to store each of said numerical values in a matrix-like fashion corresponding to the respective point's position in said scanning area.