Cree Gmbh

Ideal Industries Lighting LLC

Ashish Ekbote

Michael James Harris

Robert D Underwood

Noe Gonzalez

Kurt S Wilcox

John K Roberts

Bernd P Keller

Ihor A Lys

James Ibbetson

Daniel J Pope

John R Rowlette, Jr

Qingcong Hu

Mike Walters

Nalini Gupta

Jr John R Rowlette

A solid state light fixture includes a light emitting diode (LED) load and a driver circuit that is configured to supply a drive current to the LED load. The driver circuit may include a current supply module that is configured to reduce a drive current level during dimming of the solid state light fixture, where the current supply module is configured to operate in both a continuous conduction mode at a first dimming level and a discontinuous conduction mode at a second dimming level that is lower than the first dimming level.

Solid state light fixtures having variable current dimming and related driver circuits and methods

A method of operating a switching power converter includes operating the switching power converter in a boundary conduction mode when a switching frequency of a switch in the switching power converter is below a switching frequency threshold such than an on time of the switch is adjusted based on a desired output power of the switching power converter, and operating the switching power converter in a discontinuous conduction mode when the switching frequency of the switch is above the switching frequency threshold such that one or more of the on time of the switch and a switching period of the switch are adjusted based on the desired output power of the switching power converter and the on time of the switch is clamped at a minimum switch on time.

Power converter circuitry with improved control scheme

An LED-based lighting fixture sets or adjusts a parameter of a drive signal that is used to drive its LEDs to be more compatible with the camera system; the camera system sets or adjusts an image capture parameter to be more compatible with the LED-based lighting fixture, or a combination thereof. The drive signal may be a PWM signal with a variable PWM frequency and/or duty cycle, a variable DC signal, or any combination thereof. The parameter of the drive signal that may be set or adjusted includes, but is not limited to, a PWM period, PWM frequency, PWM duty cycle, amplitude of the active and inactive portions of the PWM signal, and the like. The image capture parameter that may be adjusted includes, but is not limited to, frame rate, frame period, integration time, gain, shutter type (i.e. rolling shutter, global shutter, etc.), and the like.

Solid state lighting fixtures and image capture systems

An apparatus includes a switched-mode converter circuit having an output configured to be coupled to at least one light-emitting device. The apparatus further includes a control circuit configured to generate a measure of a voltage magnitude of a time-varying voltage applied to an input of the switched-mode converter circuit and a measure of a dimming level to be applied to the at least one light-emitting device. The control circuit is configured to control a switch of the switched-mode converter circuit responsive to the generated measures. The control circuit may be implemented using functional units of a microcontroller.

Switched-mode converter control for lighting applications

A switched mode power supply may include circuitry configured to output a bias signal that turns off and on switching circuitry of the switched mode power supply. The circuitry may wait for a first time period determined by the bias signal, and output the bias signal to turn off the switching circuitry when the time period expires. In addition or alternatively, the circuitry may begin waiting for a second time period when the bias signal turns off the switching circuitry. The circuitry may turn on the switching circuitry either when energy in inductive storage circuitry is depleted or when the second time period expires.

Off-time control for switched mode power supplies

On-time control for switched mode power supplies

A LED lamp includes a plurality of red LEDs and a plurality of blue LEDs, a phosphor covering at least the plurality of blue LEDs, where the lamp has an LPW of at least 200 in a steady state operation.

High efficiency LED lamp

A SEPIC driver circuit with low input current ripple is disclosed. Embodiments of the present invention provide a driver circuit that accommodates universal input, has a wide output voltage range and good efficiency. An LED lighting system using such as circuit is also disclosed. In at least some embodiments, the circuit is configured as a single-ended primary inductor converter circuit using a magnetic element, and a floating capacitor is connected between the input winding and the output winding of the magnetic element. In some embodiments, an inductor is also included at the DC input to the circuit. An output rectifier such as a diode can also be connected to the output winding of the magnetic element, and an output capacitor can be connected across the output of the circuit. An FET, a bipolar transistor, or a plurality of FETs can be used as the switching device.

SEPIC driver circuit with low input current ripple

A lighting apparatus includes an input power terminal, a light source element coupled to the input power terminal, and a current bleeder module that is connected to the input power terminal and is configured to draw a current from the input power terminal responsive to a phase cut input power signal received at the input power terminal during a first portion of a period of the phase cut input power signal and is configured as an open circuit so as not to draw current from the input power terminal during a second portion of the period of the phase cut input power signal.

Lighting apparatus including a current bleeder module for sinking current during dimming of the lighting apparatus and methods of operating the same

A converter circuit includes an input filter including an input capacitor configured to filter electromagnetic interference from an input voltage. The converter circuit includes an output capacitor, a first inductor coupled to the input capacitor, a switch coupled to the first inductor and configured to control a level of current flowing in the first inductor, a coupling capacitor connected to the first inductor, and an output rectifier coupled between the coupling capacitor and the output capacitor. A damping circuit that is configured to damp a resonant frequency of the converter circuit is coupled in parallel with the coupling capacitor.

Damping resonance in a converter including a coupling capacitor

The present disclosure relates to a lighting module wherein a DC-DC converter and an LED module are provided as an integral part of the lighting module, and an AC-DC module is provided separately from the lighting module. The AC-DC module is effectively a remote power supply that can be easily replaced without having to replace, reconfigure, or otherwise modify the lighting module. With this configuration, the DC-DC module may be tuned for the particular LED module of the lighting module, and in the case of a failure of the AC-DC module, the AC-DC module can be replaced without having to replace or retune the DC-DC module.

Growing community of inventors

Carpinteria, CA, United States of America

Ashish Ekbote