Illumination device and method for avoiding an over-power or over-current condition in a power converter

摘要

An illumination device and methods are provided herein for avoiding over-current and over-power conditions in one or more power converters included within the illumination device. The illumination device may include at least a plurality of light emitting diode (LED) chains, a driver circuit, at least one power converter, and a control circuit. In some embodiments, the control circuit may be generally configured for determining a maximum safe current level and/or a maximum safe power level attributed to the power converter(s) at a present operating temperature, and for adjusting respective drive currents supplied to the plurality of LED chains by the driver circuit, so as not to exceed the maximum safe current level or the maximum safe power level at the present operating temperature. In some embodiments, a temperature sensor may be included within the illumination device for measuring the operating temperature presently associated with the power converter(s).

主权项

1. An illumination device, comprising:
a plurality of light emitting diode (LED) chains configured to produce illumination for the illumination device; a driver circuit coupled for generating and supplying a respective drive current to each of the plurality of LED chains; at least one power converter coupled for supplying power to the driver circuit, wherein the at least one power converter comprises a maximum safe current level or a maximum safe power level, which varies with temperature; a temperature sensor coupled for measuring a present temperature associated with the at least one power converter; and a control circuit coupled to the temperature sensor and the driver circuit, wherein the control circuit is configured for:
determining the maximum safe current level or the maximum safe power level of the at least one power converter at the present temperature; andadjusting the respective drive currents supplied to the plurality of LED chains, so as not to exceed the maximum safe current level or the maximum safe power level at the present temperature;an interface coupled for receiving a chromaticity setting, and wherein the control circuit is further configured for determining a maximum lumens value that can be safely produced by all LED chains at a predetermined safe temperature to achieve the chromaticity setting; andwherein the interface is further coupled for receiving a brightness setting, and wherein the control circuit is further configured for determining a target lumens value that can be safely produced by all LED chains at the present temperature to achieve the chromaticity setting without exceeding the maximum safe current level or the maximum safe power level associated with the at least one power converter.