Koninklijke Philips Corporation N.v.

Cirrus Logic Inc.

Kan Wang

John L Melanson

Eric Jerome King

Michael Allan Kost

Ramin Zanbaghi

Alfredo R Linz

Shatam Agarwal

James P McFarland

A low voltage lamp includes a boost converter stage and a load. The load may include low voltage light producing elements including low voltage light emitting diodes. The boost converter stage receives an electronic transformer output and includes an inductor coupled to a switch and a switch controller that receives one or more controller inputs. Inductor current may be returned to the transformer when the switch is closed and provided to a rectifier coupled to the load when the switch is open. Controller inputs may include a transformer input that receives the transformer output, a sense input indicating switch current, and a load input indicating load voltage. Controller logic may synchronize assertions of a control signal for the switch with edge transitions of the transformer output to maintain peak inductor current within a specified range and to selectively transfer stored energy in the inductor to the load or back to the transformer.

Boost converter stage switch controller

An electronic transformer stabilization circuit includes a detection circuit and a reactive load. The detection circuit may be configured to receive a transformer output or a transformer signal derived from the transformer output. The detection circuit may determine whether the transformer that generated the transformer output is an electronic transformer. The determination may be made based on the presence of absence of high frequency components in the transformer output. Responsive to determining that an electronic transformer generated the transformer output, the stabilization circuit may operate a switch to connect the reactive load across an output of the transformer. The reactive load may include an inductor and may be configured to draw a stabilization current from the transformer. The stabilization current may ensure that the total current drawn from the transformer exceeds an oscillation current required to maintain reliable operation of the electronic transformer.

Stabilization circuit for low-voltage lighting

A variable resistance device may be used in a dimmer compatibility circuit to reduce power dissipation in an integrated circuit of the dimmer compatibility circuit. For example, the integrated circuit may include switches coupled to resistors external to the integrated circuit. The integrated circuit may operate the switches to commutate among the external resistors and select a voltage drop that reduces a voltage at a drain voltage of the switches. The reduced drain voltage reduces power dissipation in the switches and instead dissipates the power in the external resistors.

Variable resistance device for reduced power dissipation in dimmer compatibility circuits

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Austin, TX, United States of America

Kan Wang