3m Innovative Properties Company

Martin J Vos

Raymond Patrick Johnston

Robert L Brott

Paul Edward Humpal

James F Poch

Michael Alan Meis

Glenn E Casner

Karl J L Geisler

Charles N DeVore

Kayla A Hagens

Hamid R Mortazavi

Gregory G Jager

Timothy J Pommer

Michael J Meis

One aspect of the present disclosure directs to a switch circuit including an isolator circuit to allow detection of switch states of a multilevel light switch. Another aspect of the present disclosure directs to a lighting assembly containing light emitting diodes (LEDs) of different colors, where the lighting assembly produces light of different color depending on the switch state of a multilevel light switch.

Switch circuit for LED lighting assembly adaptive to multilevel light switches

An integrator circuit for a current sensor such as a Rogowski coil. The integrator circuit includes an integrator having an input for receiving a signal from a current sensor and having an output providing a voltage signal. A high-pass filter has an input coupled to the output of the integrator and substantially removes the DC content from the voltage signal. A feedback loop has an input coupled to the output of the integrator and to the high-pass filter, and has an output providing the DC content of the voltage signal back to the input of the integrator. The integrator circuit can detect large current steps in the line conductor being monitored and can be used for line fault detection.

Electronic integrator for Rogowski coil sensors

A driver circuit is configured for connection to a power source and includes a plurality of light emitting diodes (LEDs) having at least one performance characteristic that varies according to different performance categories ranging between higher performance and lower performance. The driver circuit also includes a plurality of LED sections each populated with at least one LED of a different one of the different performance categories. Circuitry is coupled to the LED sections and configured to activate and deactivate the LED sections based on LED performance.

Sectioned network lighting device using full distribution of LED bins

A power harvester having a current transformer configured to be inductively coupled to a current conductor and a circuit for delivering power to a load. The transformer core has two sections joined together and separable from one another at interleaved portions, allowing the transformer to be installed around the current conductor. The circuit includes a rectifier coupled to the transformer and a transistor coupled in series between the rectifier and a load. The transistor receives an output current from the rectifier and provides power to the load. A resistor is coupled to the transistor and the load, and the transistor and resistor provide for limiting of the power to the load over a wide range of the conductor line currents.

Inductive power harvester with power limiting capability

A solid state area light and spotlight having a solid state light source such as LEDs, tapered light guides, and external thermal guides. The area light includes a flared light guide, and the spotlight includes a light guide with a closed end. The light guides are coupled to the light source for receiving and distributing light from the light source with the distribution being based in part upon the shape and taper of the light guides. The thermal guide provides for thermal conduction from the light source and dissipating heat through convection and radiation for cooling the light.

Solid state area light and spotlight with light guide and integrated thermal guide

A solid state light having a solid state light source such as LEDs, a light guide having an enclosed interior volume such as a bulb shape without vents, and a thermal guide. The light guide is coupled to the light source for receiving and distributing light from the light source. The thermal guide is at least partially contained within the interior volume with an air gap between a portion of the thermal guide and the light guide. The thermal guide provides for thermal conduction from the light source and dissipating heat through convection and radiation for cooling the light.

Solid state light with enclosed light guide and integrated thermal guide

A method of zero-D dimming backlights for 3D or multi-view displays using right and left image data. The method receives right and left pixel luminance values for the right and left image data, and it remaps the right and left pixel luminance values using a factor based upon an average luminance value or based upon a luminance percentile value or a modified factor that further includes the absolute difference between left and right pixel luminance values. The factor or modified factor are selectively used to remap particular right and left pixel luminance values based upon a disparity consideration. The method results in power savings by dimming the backlight without perceptible or substantial loss in brightness of the display.

Zero-D dimming for 3D displays

Ladder network circuits for controlling operation of a string of light emitting diodes (LEDS). The circuits include a number of sections connected in series. Each section includes one or more LED junctions, a variable resistive element coupled to the LED section, and a switch coupled to the variable resistive element and the LED section for controlling activation of the LED. The sections can include a transistor coupled between the switch and variable resistive element. The series of sections are connected to an AC power source, rectifier, and dimmer circuit. When receiving power from the power source, the sections activate the LEDs in sequence throughout the series of the sections. The dimmer circuit controls activation of a selection of one or more of the sections in order to activate in sequence the LEDs in only the selected sections, providing for both dimming and color control of the LEDs.

Transistor ladder network for driving a light emitting diode series string

An untethered stylus, configured to cooperate with a location sensor, includes a coil resonant circuit configured to develop an arbitrary AC voltage in response to a varying magnetic field produced by the location sensor. The coil resonant circuit includes a first capacitor and an inductive coil. A power converter includes a switch circuit having an output coupled to a second capacitor, an input coupled to the coil resonant circuit, and a threshold voltage. The switch circuit facilitates charging of the second capacitor in response to the arbitrary AC voltage and discontinuance of second capacitor charging in response to a voltage across the first capacitor reaching the threshold voltage so as to prevent diversion of a discharging current when the arbitrary AC voltage exceeds the threshold voltage. A stable DC voltage is provided at the output of the switch circuit. The power converter is preferably devoid of a Zener diode.

Untethered stylus employing low current power converter

A dimmer and an illumination apparatus are connected by a two wire circuit. The dimmer energizes the illumination apparatus and provides control of the illumination apparatus via the two wire circuit. The illumination apparatus receives all of its energization and control from the two wire circuit. Multiple strings of multiple color light emitting devices are switched on in a partitioned order during flank intervals of a switched AC power envelope on the two wire circuit.

Dimmer and illumination apparatus with amplitude ordered illumination of multiple strings of multiple color light emitting devices

An untethered device, configured to inductively couple to a source device, includes a tunable resonant circuit having a resonance frequency and configured to generate a supply voltage for the untethered device in response to a varying magnetic field produced by the source device. The tunable resonant circuit includes an inductive coil comprising a center tap and a capacitive circuit coupled to the inductive coil. The capacitive circuit includes an anti-series arrangement of varactor diodes that behave as a capacitance when placed in reverse bias. A frequency control circuit is coupled to the tunable resonant circuit and includes a control voltage source coupled to the center tap of the inductive coil. The control voltage source produces a control signal to place the varactor diodes in reverse bias and to change the capacitance of the capacitive circuit, thereby effecting a change in the resonance frequency of the tunable resonant circuit.

Frequency control circuit for tuning a resonant circuit of an untethered device

An untethered device is configured to inductively couple to a source device. The source device includes a driver circuit configured to generate a varying magnetic field and comprising a drive coil circuit. A phase detector is coupled to the driver circuit and configured to detect a phase of an input impedance of the driver circuit in response to the source device inductively coupling with the resonant circuit of the untethered device. A controller is coupled to the phase detector and the driver circuit, and is configured to adjust a frequency of a source voltage applied to the driver circuit in response to an output signal of the phase detector. The controller adjusts the source voltage frequency so that the phase of the input impedance as indicated by the output signal of the phase detector is substantially zero.

Self-tuning drive source employing input impedance phase detection

A method includes rectifying AC power and controlling switching of first, second and third currents from and rectified power and a switching sequence that is locked to the AC cycle time by sensing an amplitude of at least one of the AC power and the rectified power. The first, second and third currents are conducted through corresponding first, second and third series of color light emitting devices of different colors. The switching sequence repeats at least twice each AC cycle time.

AC illumination apparatus with amplitude partitioning

An untethered device is configured to inductively couple to a source device, which generates a varying magnetic field having a fixed frequency. The untethered device includes a tunable resonant circuit having a resonance frequency and configured to generate a supply voltage for the untethered device in response to the varying magnetic field. The untethered device further includes a frequency control circuit coupled to the tunable resonant circuit and configured to produce a control signal using signals developed within the tunable resonant circuit. The control signal is useable to adjust the resonance frequency of the tunable resonant circuit to the fixed frequency of the source device.

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Minneapolis, MN, United States of America

Martin J Vos