Ripple control of an led driving circuit
AssigneeSignify Holding B.V.
InventorsGANG WANG, LIANG SHI, JIE FU
Life of this patent
Estimating the term…
Abstract
A mechanism for selectively suppressing or allowing ripple into an output DC power for driving an LED lighting arrangement. Occupancy information is obtained and used to control the enabling and disabling of a smoothing circuit that attenuates ripple in the output DC power.
Claims15
A LED driving circuit for driving an LED lighting arrangement, the LED driving circuit comprising:
- a power supply configured to:
- receive, at an input interface, an AC input voltage, with a ripple at an AC frequency;
- convert said AC input voltage into an output DC power;
- and
- output, at an output interface, the output DC power;
- a smoothing circuit configured to smooth the output DC power and remove at least part of the ripple at the AC frequency from the output DC power, and
- a controller to selectively enable or disable the smoothing circuit,
- wherein:
- the LED driving circuit further comprises a control interface configured to receive a control command carrying occupancy information indicating an occupation of a space by an object;
- and
- the controller is configured to selectively enable or disable the smoothing circuit responsive to the occupancy information.
The LED driving circuit of claim 1-96 wherein the controller is configured to prevent power loss in and/or extend the lifetime of the smoothing circuit when the controller disables the smoothing circuit.
The LED driving circuit of claim wherein the smoothing circuit comprises a power factor correction converter of the power supply and/or a secondary switched-mode power supply connected in series with the output interface of the power supply, and the controller is configured to bypass the smoothing circuit in order to disable the smoothing circuit.
The LED driving circuit of wherein the smoothing circuit comprises a linear switch connected in series with the output interface of the power supply and the controller is configured to make the linear switch enter a fully conductive mode in order to disable the smoothing circuit.
The LED driving circuit of cla wherein the smoothing circuit comprises at least one capacitor-switch pair connected in parallel with the output interface of the power supply, each capacitor-switch pair comprising an output capacitor and a switch connected in series, and the controller is configured to open the switch so as to disconnect the output capacitor from the output interface of the power supply in order to disable the smoothing circuit.
A method of producing an output DC power for driving an LED lighting arrangement, the method comprising:
- receiving, at an input interface, an AC input voltage, with a ripple at an AC frequency;
- converting said AC input voltage into an output DC power;
- outputting, at an output interface, the output DC power;
- receiving a control command carrying occupancy information indicating an occupation of a space by an object;
- and
- selectively enabling and disabling a smoothing circuit responsive to the occupancy information, wherein, when enabled, the smoothing circuit is configured to smooth the output DC power and remove at least part of the ripple at the AC frequency from the output DC power.
Dependencies are inferred from the claim text.