Load control device for a light-emitting diode light source
First Claim
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, the load regulation circuit comprising an inverter circuit characterized by an operating period and a duty cycle; and
a control circuit coupled to the load regulation circuit and configured to control an average magnitude of the load current, the control circuit configured to operate in a normal mode and a burst mode, the burst mode comprising an active state during an active state period of a burst mode period and an inactive state during an inactive state period of the burst mode period;
wherein, during the normal mode, the control circuit is configured to regulate the average magnitude of the load current towards a target load current by adjusting an on time of the inverter circuit; and
wherein, during the burst mode, the control circuit is configured to adjust the operating period of the inverter circuit to a low-end operating period by adjusting the on time of the inverter circuit to a value less than or equal to a minimum on time while holding the duty cycle of the inverter circuit constant, the control circuit further configured to regulate the average magnitude of the load current towards the target load current by adjusting a length of the active state period and a length of the inactive state period.
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Accused Products
Abstract
A load control device for an electrical load may operate in a normal mode and a burst mode to adjust the amount of power delivered to the electrical load. The load control device may comprise a control circuit that operates in the normal mode to regulate an average magnitude of a load current conducted through the load between a maximum rated current and a minimum rated current. During the normal mode, the control circuit may control the operating period of a load regulation circuit between a high-end operating period and a low-end operating period. The control circuit may operate 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 may adjust the low-end operating period to be less than or equal to a minimum on time of the load regulation circuit.
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Citations
34 Claims
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1. A load control device for controlling an amount of power delivered to an electrical load, the load control device comprising:
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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, the load regulation circuit comprising an inverter circuit characterized by an operating period and a duty cycle; and a control circuit coupled to the load regulation circuit and configured to control an average magnitude of the load current, the control circuit configured to operate in a normal mode and a burst mode, the burst mode comprising an active state during an active state period of a burst mode period and an inactive state during an inactive state period of the burst mode period; wherein, during the normal mode, the control circuit is configured to regulate the average magnitude of the load current towards a target load current by adjusting an on time of the inverter circuit; and wherein, during the burst mode, the control circuit is configured to adjust the operating period of the inverter circuit to a low-end operating period by adjusting the on time of the inverter circuit to a value less than or equal to a minimum on time while holding the duty cycle of the inverter circuit constant, the control circuit further configured to regulate the average magnitude of the load current towards the target load current by adjusting a length of the active state period and a length of the inactive state period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An LED driver for controlling an intensity of an LED light source, the LED driver comprising:
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an LED drive circuit configured to control a magnitude of a load current conducted through the LED light source and to control the intensity of the LED light source, the LED drive circuit comprising an inverter circuit characterized by an operating period and a duty cycle; and a control circuit coupled to the LED drive circuit and configured to control an average magnitude of the load current, the control circuit configured to operate in a normal mode and a burst mode, the burst mode comprising an active state during an active state period of a burst mode period and an inactive state during an inactive state period of the burst mode period; wherein, during the normal mode, the control circuit is configured to regulate the average magnitude of the load current towards a target load current by adjusting an on time of the inverter circuit; and wherein, during the burst mode, the control circuit is configured to adjust the operating period of the inverter circuit to a low-end operating period by adjusting the on time of the inverter circuit to a value less than or equal to a minimum on time while holding the duty cycle of the inverter circuit constant, the control circuit further configured to regulate the average magnitude of the load current towards the target load current by adjusting a length of the active state period and a length of the inactive state period. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A load control device for controlling an amount of power delivered to an electrical load, the load control device comprising:
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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, the load regulation circuit comprising an inverter circuit characterized by an operating period; and a control circuit coupled to the load regulation circuit and configured to adjust an on time of the inverter circuit to control an average magnitude of the load current toward a target load current; wherein, on a condition that the target load current is less than a low-end transition value, the control circuit is configured to adjust the operating period of the inverter circuit to a low-end operating period by adjusting the on time of the inverter circuit to a predetermined on time, and wherein, on a condition that the target load current is greater than the low-end transition value, the control circuit is configured to adjust the operating period of the inverter circuit between the low-end operating period and a high-end operating period. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34)
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Specification