LOAD CONTROL DEVICE FOR A LIGHT-EMITTING DIODE LIGHT SOURCE

摘要

A load control device for controlling the amount of power delivered to an electrical load is able to operate in a burst mode to adjust the amount of power delivered to the electrical load to low levels. The load control device comprises a control circuit that operates in a normal mode to regulate an average magnitude of a load current conducted through the load to a target load current that ranges from a maximum rated current to a minimum rated current. The control circuit operates in the burst mode to regulate the average magnitude of the load current below the minimum rated current. During the burst mode, the control circuit regulates a peak magnitude of the load current to the minimum rated current during a first time period, and stops regulating the load current during a second time period, such that the average magnitude of the load current is below the minimum rated current.

主权项

1. A load control device for controlling an amount of power delivered to an electrical load, the load control device comprising:
a load regulation circuit configured to control a magnitude of a load current conducted through the electrical load to control the amount of power delivered to the electrical load; and a control circuit coupled to the load regulation circuit and configured to adjust an average magnitude of the load current, wherein the control circuit is configured to operate in a normal mode to regulate the average magnitude of the load current to a target load current that ranges from a maximum rated current to a minimum rated current, the control circuit further configured to operate in a burst mode to regulate the average magnitude of the load current below the minimum rated current; wherein, during the burst mode, the control circuit is configured to regulate a peak magnitude of the load current to the minimum rated current during a first time period using a control loop, and to stop regulating the load current during a second time period resulting in the average magnitude of the load current being below the minimum rated current, the control circuit configured to freeze the control loop during the second time period.