L3 Cincinnati Electronics Corporation

L3harris Technologies, Inc.

Justin Graves

A method of controlling a switching power supply comprises: generating a pulse train; applying the pulse train to a switching transistor of the switching power supply to cause switching of the switching transistor on and off to convert an input voltage applied to the switching transistor to an output voltage, which rises while switching the switching transistor on and off and falls while not switching the switching transistor on and off; and performing hysteretic voltage control of the output voltage by first controlling dropping pulses of the pulse train so that the output voltage remains between hysteretic voltage thresholds including an overvoltage threshold and an undervoltage threshold that is less than the overvoltage threshold.

Hysteretic power supply control method

A circuit to rectify an alternating current (AC) signal produced by an output coil of a transformer responsive to an input current in an input coil of the transformer comprises: an output node and a return node coupled to an output load; a first rectifier, coupled to a first terminal of the output coil and the return node, to rectify the AC signal to supply a current to the output node when the input current is ON; a second rectifier, coupled to a second terminal of the output coil and the return node, to rectify the AC signal to supply a current to the output node when the input current is OFF; and a voltage clamp to clamp a first voltage transient and a second voltage transient of the AC signal that occur at the first terminal and the second terminal when the input current is switched OFF and ON.

Switching power supply rectifier with voltage clamps to clamp voltage transients on output coil of transformer

Embodiments described herein are directed to inrush current limiters having a transformer. In one embodiment, an inrush current limiter includes a transformer including a primary winding, a secondary winding and a saturable magnetic core shared therebetween, a resistor connected in parallel with the secondary winding, wherein an impedance of the resistor is reflected across the transformer when a voltage is applied across the primary winding and the saturable magnetic core is not saturated, and a diode connected between the primary winding and ground.

Magnetically saturable components and circuits

A regulated power supply includes a capacitively isolated feedback circuit and a pulse width modulator (PWM) operable to produce a plurality of pulses at an output and receive a sampled voltage at a feedback input thereof. The capacitively isolated feedback circuit includes a capacitively isolated gate drive circuit directly coupled to the PWM output and configured to produce a plurality of isolated pulses from the plurality of pulses received from the PWM output. The capacitively isolated feedback circuit also includes a forward converter feedback circuit, which includes a switching transistor directly coupled to the capacitively isolated gate drive circuit for receiving the plurality of isolated pulses at a gate of the switching transistor and a feedback transformer directly coupled to the PWM for providing the sampled voltage at the feedback input. The plurality of isolated pulses causes the feedback transformer to sample a load voltage as the sampled voltage.

Capacitively isolated feedback circuits and regulated power supplies incorporating the same

Embodiments described herein are directed to power switching circuits having a saturable inductor. In one embodiment, a power switching circuit includes a power switch assembly operable to be connected to a power source. The power switch assembly includes a plurality of parallel power switches connected to and receiving current from the power source and a saturable inductor electrically coupled in series with the plurality of parallel power switches.

Power switching circuits having a saturable inductor

Embodiments described herein are directed to an energy-harvesting circuit configured to harvest energy from a power converter circuit within a switch mode power supply and generate a positive, a negative or a bipolar power supply rail to power load circuitry. The energy-harvesting circuit includes a transformer, a coupling capacitor, a diode and a capacitor. The transformer has a primary winding, a secondary winding and a magnetic core shared therebetween. The primary winding is electrically connected between a drain and a source of a transistor switch connected to the power converter circuit. The coupling capacitor is electrically connected between the drain and the primary winding and configured to provide a reset mechanism for the magnetic core. The anode of the diode is electrically connected to the secondary winding. The capacitor is electrically connected in series with the cathode of the diode and in parallel with the load circuitry.

Energy-harvesting power supplies

Magnetically isolated feedback circuits and regulated power supplies are disclosed. In some embodiments, a magnetically isolated feedback circuit includes an isolated gate drive circuit and a forward converter circuit. The isolated gate drive circuit is operable to receive a plurality of pulses, wherein the isolated gate drive circuit produces a plurality of isolated bi-polar pulses from the plurality of pulses. The forward converter circuit is electrically coupled to the isolated gate drive circuit and is operable to be electrically coupled to a load. The plurality of isolated bi-polar pulses causes the forward converter circuit to sample a voltage at the load as a sampled voltage. The forward converter circuit is operable to provide the sampled voltage to a feedback input of a pulse width modulator.

Growing community of inventors

Middletown, OH, United States of America

Justin Graves