Abstract: A load management system for monitoring the output from a power supply and managing the load on said power supply, said load management system comprising a hysteresis circuit for signaling a load element to stop drawing current when an output voltage at said output falls below a first threshold and for signaling said load element to resume drawing current when said output voltage rises above a second threshold, said hysteresis circuit comprising a first state sensing circuit having an input coupled to said output and for signaling whether said output voltage is greater than or less than said first voltage threshold, a second state sensing circuit having an input coupled to said output and for signaling whether said output voltage is greater than or less than a second voltage threshold, and a state transition circuit having a first input coupled to the output of said first state sensing circuit and a second input coupled to the output of said second state sensing circuit, said state transition circuit having a

Abstract: A power input protection circuit for an electrical device including a pass device having a full-conduction state, an off state, and a current regulation state, a control device coupled to the pass device for signaling the pass device to operate in one of the full-conduction, off or current regulation states, a high-voltage sensing circuit coupled to the control device for signaling the presence of an over-voltage condition to the control device, a high-current sensing circuit coupled to the control device for signaling the presence of an over-current condition to the control device, and an energy storage circuit coupled to the regulator and for supplying energy to the regulator when the pass device is in the off state is disclosed.

Abstract: An energy storage system is provided that includes input terminals for receiving input energy from a remote power source and an energy storage device coupled to the input terminals. The energy storage device is operative to store at least of portion of the input energy and to supply stored energy to the input terminals. A pump device is also coupled to the input terminal and to the storage device. The pump device is operative to cause the energy storage device to store at least a portion of the input energy when the input energy level is above a first threshold level, and to cause the energy storage device to supply energy to the input terminals when the input energy level is below a second threshold level. The energy storage system is optionally provided with a current limiter for added protection against short circuits. In one embodiment, the current limiter is bi-direction; it protects against short circuits originating at both the power source and within the energy storage system.

Abstract: A four quadrant power conversion topology comprising a multi-winding inductor, four switches, and four diodes is disclosed. The four quadrant power conversion is utilized in a number of power conversion devices such as a power efficient non-linear power amplifier that comprises the 4Q power conversion topology of the present invention and a switch-control-signal generator coupled to the 4Q power conversion topology. The switch-control-signal generator generates switch activation signals for driving the four switches of the 4Q power conversion topology.

Abstract: A line feed circuit employing a low-inductance transformer, and providing a major portion of the terminating impedance as line feed resistors connected between a telephone line and the transformer primary. A low impedance output amplifier drives a low resistance transformer secondary, thus reducing the need for large transformer inductances. By connecting the line feed resistors between the transformer and the telephone line, high voltage surges are absorbed by the resistors, and thus little is dissipated in the transformer. The transformer can be made physically small, because of the reduced inductance, reduced winding insulation, and reduced power requirements. The resistance forward type of line feed circuit lends itself well to simple implementation with flux cancellation and impedance synthesis circuits.

Abstract: A circuit for increasing the apparent inductance presented by a transformer to a differential signal. The circuit may be used in a battery feed interface circuit for providing battery power to a subscriber's telephone or in a current sink interface circuit for providing a low impedance DC loop closure toward a telephone line feed circuit while maintaining a high impedance for differential AC signals. In either usage the inductance multiplier circuit always multiplies the primary inductance of the transformer by a factor which is one plus a positive number. The transformer has three windings. The multiplication is accomplished by a current source which provides to the third winding a current which flows therein in a manner so as to oppose the current flowing in that winding due to the voltage induced in that winding when the first and second windings are excited by the differential AC signal.

Abstract: A high-frequency negative resistance circuit for use in a voltage controlled crystal oscillator has a pair of input terminals thereby defining an input current and input voltage. The high-frequency negative resistance circuit includes a sensing circuit for sensing the input current, a biasing voltage source and a load impedance connected to the voltage source. The high-frequency negative resistance circuit further comprises a current mirror circuit connected to the sensing circuit and to the load impedance for producing a current in the load impedance. The current in the load impedance is approximately equal to the input current. The current mirror circuit also controls the sensing circuit to cause the input voltage to decrease as the input current increases. Decreasing input voltage with increasing input current defines the negative resistance. When this negative resistance circuit is configured with a crystal and a voltage controlled capacitance, an oscillator capable of high-frequency operation results.