Koninklijke Philips Corporation N.V.

Semiconductor Components Industries, LLC

Silanna Asia Pte Ltd

Ningliang Mi

Srinivasa M Baddela

William Lawrence Keith

Robert Alexander Erhardt

Ajay Tripathi

Raman Nair Harish Gopala Pillai

Jerzy Janczak

Rama Venkat

Anand Upadhyay

Robert J Erhardt

A transformer includes first and second primary windings serially electrically connected in a primary-side series combination. The transformer further includes a secondary winding disposed between the first primary winding and the second primary winding. The transformer further includes first and second shielding windings serially electrically connected in a shielding series combination. The first shielding winding is disposed between the first primary winding and the secondary winding, and the second shielding winding is disposed between the second primary winding and the secondary winding.

Transformer with interleaved shielding windings

In an embodiment, an LED control circuit may include a first circuit configured to form a reference signal having a waveform of a rectified ac signal. The LED control circuit may also include a first regulator circuit configured to regulate a first LED current from a first LED during a first portion of the reference signal to have a waveshape that follow the reference signal waveform but not receive the first current during a second portion of the reference signal. The LED control circuit may also include a second regulator circuit configured to regulate a second current from the first LED and from a second LED during the second portion of the reference signal to have a waveshape that follows the reference signal waveform.

LED control circuit and method therefor

A light emitting diode (LED) direct AC drive (DACD) circuit includes LED groups that are connected in series. An LED DACD controller includes current regulators that regulate the LED current of the LED groups. The LED DACD controller measures an on-time of an LED group, and regulates the LED current of the LED groups based on the measured on-time of the LED group.

LED direct AC drive circuit

An electronic ballast with dimming circuit including an electronic ballast dimming circuit receiving an analog dimming signal, the electronic ballast dimming circuit including an input dimming circuit () operable to receive the analog dimming signal () at an analog dimming signal input (); and an output dimming circuit () operably connected to the input dimming circuit (), the output dimming circuit () being operable to receive a fixed frequency signal () having a variable duty cycle and to generate an analog dimming control signal () in response to the analog dimming signal (). Output voltage at the analog dimming signal input () is a function of the variable duty cycle of the fixed frequency signal () when the analog dimming signal () is not present at the analog dimming signal input ().

Electronic ballast with dimming circuit

A method and system of flicker suppression for an LED. The method includes providing a power supplyfor supplying current to the LED. The power supplyincludes a flicker suppressorand is responsive to a dim command signal. The method further includes receiving the dim command signal at the power supply, switching the current on and limiting the current to maintain LED light output below 110 percent of the LED light output corresponding to the dim command signal.

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Arlington Heights, IL, United States of America

Ningliang Mi