US 9,288,850 B2Granted

Control circuits, integrated circuits and illuminating apparatuses having the same

AssigneeGroups Tech Co., Ltd.

InventorsChing Sheng Yu, Chih Liang Wang, Kuang Hui Chen

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Abstract

Disclosed are control circuits capable of auto-configuring two LED arrays either in parallel when the two LED arrays are operating off of 100±20% V AC voltage sources or in series when the two LED arrays are operating off of 200±20% V AC voltage sources according to the detection of the AC input voltage magnitude. The disclosed control circuits, ruling over the parallel or series configuration of the two LED arrays, could be implemented in discrete forms or as integrated circuits (IC).

Claims20

Dependent claims

A control circuit for auto-configuring two strings of LED arrays to be lit up in series or in parallel, comprising:

a first switch, coupled between ground and a cathode of a first extrinsic LED array;
a second switch, coupled between at least one extrinsic voltage source and an anode of a second extrinsic LED array, wherein the at least one extrinsic voltage source provides a dual-range sinusoidal input;
a freewheeling switch, having a channel lying between the cathode of the first extrinsic LED array and the anode of the second extrinsic LED array;
and
a switch controller, coupled to an output terminal of a voltage divider, for detecting a sampled voltage of the at least one extrinsic voltage source by the voltage divider and comparing the sampled voltage with an intrinsic reference or an intrinsic threshold voltage, wherein the switch controller comprises a peak rectifier as well as an interlock circuit, the peak rectifier is used for holding a sampled peak voltage of the at least one extrinsic voltage source serving as a signal input to the interlock circuit, and
when the at least one extrinsic voltage source comes within a low range, the switch controller switches on the first switch and the second switch at the same time and the freewheeling switch is off, so that both the first extrinsic LED array and the second extrinsic LED array are lit up in parallel, and
when the at least one extrinsic voltage source comes within a high range, the switch controller switches off the first switch and the second switch at the same time, and the freewheeling switch is on, so that the first and the second extrinsic LED array are lit up in series, wherein when the sampled peak voltage is less than the intrinsic reference or the intrinsic threshold voltage, the first and the second extrinsic LED array are lit up in a time-invariant parallel configuration locked down by the interlock circuit regardless of the dual-range sinusoidal input, when the sampled peak voltage is no less than the intrinsic reference or the intrinsic threshold voltage, the first and the second extrinsic LED array are lit up in a time-invariant series configuration locked down by the interlock circuit regardless of the dual-range sinusoidal input.

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Dependencies are inferred from the claim text.

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Abstract

A control circuit for auto-configuring two strings of LED arrays to be lit up in series or in parallel, comprising:

a first switch, coupled between ground and a cathode of a first extrinsic LED array;
a second switch, coupled between at least one extrinsic voltage source and an anode of a second extrinsic LED array, wherein the at least one extrinsic voltage source provides a dual-range sinusoidal input;
a freewheeling switch, having a channel lying between the cathode of the first extrinsic LED array and the anode of the second extrinsic LED array;
and
a switch controller, coupled to an output terminal of a voltage divider, for detecting a sampled voltage of the at least one extrinsic voltage source by the voltage divider and comparing the sampled voltage with an intrinsic reference or an intrinsic threshold voltage, wherein the switch controller comprises a peak rectifier as well as an interlock circuit, the peak rectifier is used for holding a sampled peak voltage of the at least one extrinsic voltage source serving as a signal input to the interlock circuit, and
when the at least one extrinsic voltage source comes within a low range, the switch controller switches on the first switch and the second switch at the same time and the freewheeling switch is off, so that both the first extrinsic LED array and the second extrinsic LED array are lit up in parallel, and
when the at least one extrinsic voltage source comes within a high range, the switch controller switches off the first switch and the second switch at the same time, and the freewheeling switch is on, so that the first and the second extrinsic LED array are lit up in series, wherein when the sampled peak voltage is less than the intrinsic reference or the intrinsic threshold voltage, the first and the second extrinsic LED array are lit up in a time-invariant parallel configuration locked down by the interlock circuit regardless of the dual-range sinusoidal input, when the sampled peak voltage is no less than the intrinsic reference or the intrinsic threshold voltage, the first and the second extrinsic LED array are lit up in a time-invariant series configuration locked down by the interlock circuit regardless of the dual-range sinusoidal input.

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