US 10,455,674 B2 · Methods and systems for controlling an electrical load

Abstract

An electronic dimming ballast or light emitting diode (LED) driver for driving a gas discharge lamp or LED lamp may be operable to control the lamp to avoid flickering and flashing of the lamp during low temperature or low mercury conditions. Such a ballast or driver may include a control circuit that is operable to adjust the intensity of the lamp. Adjusting the intensity of the lamp may include decreasing the intensity of the lamp. The control circuit may be operable to stop adjustment of the intensity of the lamp if a magnitude of the lamp voltage across the lamp is greater than an upper threshold, and subsequently begin to adjust the intensity of the lamp when the lamp voltage across the lamp is less than a lower threshold. Subsequently beginning to adjust the intensity of the lamp may include subsequently decreasing the intensity of the lamp.

Claims20

Dependent claims

A method for controlling a magnitude of a load current delivered to an electrical load, the method comprising:

receiving a command to adjust to the magnitude of the load current a target magnitude of the load current;
adjusting the magnitude of the load current toward the target magnitude in response to receiving the command;
determining that a magnitude of a load voltage across the electrical load is equal to or greater than an upper voltage threshold;
maintaining the magnitude of the load current constant for a period of time based on the magnitude of the load voltage being equal to or greater than the upper voltage threshold;
determining that the magnitude of the load voltage is less than a lower voltage threshold;
and
adjusting the magnitude of the load current toward the target magnitude based on the magnitude of the load voltage being less than the lower voltage threshold.

4 more elements

A load control device for controlling a magnitude of a load current delivered to an electrical load, the load control device comprises:

a load voltage measurement circuit configured to generate a load voltage feedback signal representative of a magnitude of a load voltage produced across the electrical load;
a control circuit configured to:
receive a command to adjust to the magnitude of the load current a target magnitude of the load current;
adjust the magnitude of the load current toward the target magnitude in response to receiving the command;
determine that the magnitude of the load voltage from the load voltage measurement circuit is equal to or greater than an upper voltage threshold;
maintain the magnitude of the load current constant for a period of time based on the magnitude of the load voltage being equal to or greater than the upper voltage threshold;
determine that the magnitude of the load voltage is less than a lower voltage threshold;
and
adjust the magnitude of the load current toward the target magnitude based on the magnitude of the load voltage being less than the lower voltage threshold.

6 more elements

Dependencies are inferred from the claim text.

Methods and systems for controlling an electrical load

Life of this patent

Methods and systems for controlling an electrical load

Life of this patent

Abstract

Claims20