Patent application number | Description | Published |
20080239761 | Forward power converter controllers - This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). | 10-02-2008 |
20080239762 | Forward power converter controllers - This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). | 10-02-2008 |
20080239764 | Forward power converter controllers - This invention relates to control techniques and controllers for resonant discontinuous forward power converters (RDFCs). | 10-02-2008 |
20090040796 | BIPOLAR TRANSISTOR DRIVERS - We describe a switching power converter comprising a bipolar switching device (BJT or IGBT) switching an inductive load, and including a closed-loop control system. The control system comprises a voltage sensing system to sense a voltage on a collector terminal of the switching device and provide a voltage sense signal; a controller; and a drive modulation system coupled to an output of the controller for modulating a drive to the control terminal of said bipolar switching device responsive to a controller control signal; wherein said controller is configured to monitor changes in the sensed voltage during a period when said switching device is switched on and to control said drive modulation system to control the degree of saturation of said bipolar switching device when the device is switched on and hence improve turn-off times. | 02-12-2009 |
20090212754 | NOISE REDUCTION SYSTEMS AND METHODS - We describe a switch mode power supply having a power input, a switch, a transformer, and a power output. The transformer has a primary winding coupled to said power input via said switch, and a secondary winding coupled to said power output. The transformer further comprises an auxiliary winding and a coupling structure capacitatively coupled to said secondary winding of said transformer; wherein said coupling structure does not comprise a shield or screen between said primary and secondary windings. The switch mode power supply further comprises a coupling capacitor connected between said coupling structure and said auxiliary winding to provide a noise suppression voltage from said auxiliary winding to said secondary winding to at least partially cancel a common mode noise voltage on said secondary winding from unshielded coupling from said primary winding. | 08-27-2009 |
20140232187 | AUXILIARY RECHARGE - The present invention generally relates to powering a switching controller of a switch mode power converter (SMPC), and more particularly to a method of providing power to a switching controller of a SMPC, to a charging circuit for supplying charge to a charge store for providing power to a switching controller of a SMPC, and to an SMPC comprising such a circuit. A method of providing power to a switching controller of a switch mode power converter (SMPC), the SMPC having: an inductive component having a winding coupled to receive power from an input to said SMPC; a switching circuit comprising first and second switching transistors, said first transistor coupled in series between said winding and said second transistor; a switching controller to control switching of said second transistor; and a charge store to provide power to said switching controller, the method comprising: flow of current from said winding through said first transistor; and diverting said current through a conduction path to said charge store. | 08-21-2014 |
20140355314 | STORAGE TIME CONTROL - We describe a method of controlling turn off time delay of a switching device of a switch mode power converter (SMPC). The SMPC has an inductive component comprising an input winding coupled to receive power from an input; and a switching device to, when on, conduct input winding current. In embodiments the method comprises applying turn on and turn-off signals to the switching device; applying at least one turn off signal, to initiate turning off of the switching device, and detecting a sensing signal from a further winding of the inductive component, inductively coupled to the input winding, to thereby indicate an end of a turn off time delay or duration. The method controls the turn on signal for a subsequent switching cycle of the SMPC device to regulate the turn off delay time. | 12-04-2014 |
20150016151 | BJT DRIVE SCHEME - The invention generally relates to switch mode power converters (SMPCs). and methods for providing supplementary base drive to a bipolar transistor of an SMPC, and more particularly to a switching control circuit for a SMPC, a said SMPC having an inductive component coupled to receive power from an input to the SMPC, a bipolar transistor coupled to control current flow in the inductive component, an auxiliary power rail, a charge store for supplying power via the auxiliary rail to a switching control circuit for driving the bipolar transistor, and a bootstrap circuit for bleeding current from the input to the bipolar transistor to thereby provide an amplified current to the charge store, the switching control circuit comprising: a base current line for coupling to a base terminal of a said bipolar transistor, an emitter current line for coupling to an emitter terminal of a said bipolar transistor, an auxiliary line for coupling to a said auxiliary power rail, and at least one reference line for coupling to a reference voltage; a base current switch configured to controllably couple a base current source to the base current line; an emitter current switch configured to controllably couple the emitter current line to a said reference line; a bootstrap element for bleeding current from the emitter current line to the auxiliary line, the bootstrap element further operable to block a said current according to a current or voltage bias; a base discharge switch configured to controllably bleed current from the base current line to a said reference line; and a supplementary base drive line for coupling to a series circuit comprising a supplementary base drive resistor and current control element coupled in series, a said series circuit for bleeding current from a said input to a said base terminal, a said current control element for blocking current flow from a said bootstrap circuit to a said supplementary base drive resistor. | 01-15-2015 |