Texas Instruments Corporation

Texas Instruments (Cork) Limited

Commergy Technologies Limited

Andrew Bernard Keogh

George Young

William James Long

Seamus Martin O'Driscoll

Peter Michael Meaney

Joseph Michael Leisten

Garry Trevor Tomlins

Brian Gaynor

Example embodiments of the systems and methods of CCM primary-side regulation disclosed herein subtract an estimate of the secondary IR drop from each output voltage sample. This allows a fixed sample instant to be set (with regard to the beginning of the off or flyback interval), and removes the need to hunt for or adjust to an optimum sample instant, or one with minimum IR drop error. The estimate of the IR drop may be adjusted on a cycle-by-cycle basis, based on the commanded primary peak current, knowing that the peak secondary current will be directly proportional by the turns ratio of the transformer. For improved accuracy, an adjustment may be made for the decay of secondary current during the delay to the sample instant, if the inductance value is known.

Systems and methods of CCM primary-side regulation

This invention relates to a control circuit for a buck power factor correction (PFC) stage. Buck PFC stages are commonly used in low cost, high efficiency power converters. These buck PFC stages are typically controlled using a very slow control loop with a crossover frequency of the order of 10 to 20 Hz. However, such a slow response is unsuitable for applications requiring overvoltage protection. The present invention overcomes the problems with the known control circuits for buck PFC stages by implementing a two stage control circuit having a fast outer loop control circuit and a slow inner loop control circuit. The fast outer loop control circuit is in operation during low load conditions and the slow inner loop control circuit is only active under load.

Control circuit for a buck power factor correction stage

A PWM modulator as might be used in a power converter, a drive signal will be generated on an output pin of an integrated circuit PWM controller device which is used to drive the output when the modulator is required to be on.

PWM controller with drive signal on current sensing pin

The present invention relates to a transformer assembly () and a process for manufacturing same. The transformer () comprises a primary winding () wound on a PCB () and a secondary winding () mounted adjacent to the primary winding. The primary winding comprises a spiral coil, for example of wire or insulated wire, wound on the PCB. Gate drive windings () are incorporated in the PCB () and there is therefore very close coupling between the primary winding and the gate drive windings. Furthermore, the secondary winding () is a center-tapped secondary having two halves. A flux balance winding () is provided to connect the two halves of the center-tapped secondary winding () and minimize leakage inductance thereby reducing power loss and spiking effects and obviating the need for complex control arrangements.

Transformer assembly

This invention relates to an ACDC converter () comprising a converter input () and a converter output (), a pre-regulation stage () and a DC transformer stage () comprising a transformer input stage () and a transformer output stage (). The transformer input stage comprises a double ended converter and there is further provided a controller () for providing a control signal to the double ended converter. The controller () operates the ACDC converter using burst mode control and by sending control signals comprising pulse sets that are designed to provide substantially zero net magnetising current in the double ended converter. The pre-regulation stage preferably comprises a buck converter which in turn also provides power factor correction to the input of the ACDC converter.

ACDC converter

A heavy duty cycle power converter () has current mode control in which the closed loop control is carried out by a controller () using a desired signal () which is a function of the difference between the desired duty cycle () and the measured duty cycle (). This fluctuates current mode control without voltage feedback.

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Glanmire, Ireland

Andrew Bernard Keogh