Brightness control system for decorative light strings

A modular constant-brightness lighting system comprising:

• a battery-module connector configured to electrically connect to one or more interconnected battery modules, the one or more interconnected battery modules configured to provide a battery-module voltage that varies in response to one or more battery conditions;
• a light-string connector configured to connect to one or more interconnected light strings;
• a load sensor configured to sense a signal indicative of a brightness of the one or more interconnected light strings connected to the light-string connector;
• and
• a switching supply configured to draw operating power from the one or more interconnected battery modules connected to the battery-module connector and to supply lighting power to the one or more interconnected light strings connected to the light-string connector, wherein the switching supply adjusts the supplied lighting power such that the sensed signal indicative of the brightness is within plus or minus 10% of a target signal indicative of a target brightness, the target signal being a constant and independent of the battery voltage.

A method of controlling a constant brightness in a light string, the method comprising the steps of:

• providing one or more batteries, the one or more batteries configured to provide a battery voltage that varies in response to one or more battery conditions;
• drawing operating power from the one or more batteries;
• providing a light string having a plurality of LEDs distributed along a length of the light string;
• supplying lighting power to the provided light string;
• sensing a signal indicative of a brightness of the provided light string;
• comparing the sensed signal indicative of the brightness to a target signal indicative of a target brightness;
• and
• adjusting the supplied lighting power based on the comparison of the sensed signal indicative of the brightness to the target signal indicative of the target brightness, wherein the adjusted supplied lighting power results in the sensed signal indicative of the brightness being within plus or minus 10% of the target signal indicative of the target brightness, the target signal being independent of the battery voltage.