Phase angle measurement of a dimming circuit for a switching power supply
AssigneePower Integrations, Inc.
InventorsYury Gaknoki, Mingming Mao, Tiziano Pastore
Life of this patent
Estimating the term…
Abstract
An example switched mode power supply includes a timer, a threshold adjust circuitry, a comparator, and a control circuitry. The timer times a duration between crossings of a phase-dimmed signal across a first threshold. The threshold adjust circuitry adjusts a second threshold representative of a desired output of the switched mode power supply, where the second threshold is adjusted responsive to the timed duration between crossings. The comparator compares a feedback signal with the second threshold and generates a comparison result. The control circuitry controls switching of a power switch responsive to the comparison result to regulate the output of the switched mode power supply.
Claims13
A switched mode power supply, comprising:
- a timer to time a duration between crossings of a phase-dimmed signal across a first threshold;
- a threshold adjust circuitry to adjust a second threshold representative of a desired output of the switched mode power supply, wherein the second threshold is adjusted responsive to the timed duration between crossings;
- a comparator to compare a feedback signal representative of an output of the switched mode power supply with the second threshold and to generate a comparison result;
- and
- control circuitry to control switching of a power switch of the switched mode power supply responsive to the comparison result to regulate the output of the switched mode power supply.
A switched mode power supply, comprising:
- a detector to detect a time between transitions within a cycle of a dimmer output signal, wherein the transitions include transitioning between a dimmed portion of the dimmer output signal and a non-dimmed portion of the dimmer output signal;
- a threshold adjust circuitry to adjust a threshold representative of the desired output responsive to the detected time between transitions;
- a comparator to compare a feedback signal representative of an output of the switched mode power supply with the threshold and to generate a comparison result;
- and
- control circuitry to control the switching of a power switch responsive to the comparison result to regulate the output of the switched mode power supply.
A device comprising:
- a dimmer circuit coupled to remove a portion of a cycle of an ac input voltage and to output a dimmer output voltage in response thereto;
- a switched mode power supply coupled to receive the dimmer output voltage and to supply a load with an output current that has a value that adjusts in response to a duration of the portion of the cycle of the ac input voltage that is removed by the dimmer circuit, the switched mode power supply including:
- a timer coupled to generate a signal representative of the duration of the portion of the cycle of the ac input voltage that is removed by the dimmer circuit;
- a threshold adjust circuitry to adjust a threshold representative of the desired output in response to the signal representative of the duration of the portion of the cycle of the ac input voltage that is removed by the dimmer circuit;
- a comparator to compare a feedback signal representative of an output of the switched mode power supply with the threshold and to generate a comparison result;
- and
- a drive signal generator coupled to control switching of a switch to regulate the output current in response to the comparison result.
Dependencies are inferred from the claim text.