US 11,452,186 B1Granted

LED driver with rectified voltage monitor

AssigneeCuvee Systems, Inc.

InventorsDongsheng Zhou, Lanh Cong Nguyen

Life of this patent

Estimating the term…

Loading patent…

Abstract

Methods and systems for improved dimming of LED based illumination devices are described herein. An AC input voltage provided to an LED driver is rectified and the rectified signal is monitored by a Rectified Voltage Monitor (RVM) circuit. The RVM circuit generates a low voltage monitor signal indicative of the shape and peak voltage of the rectified signal. The monitor signal and the rectified signal are communicated to a power converter of the LED driver. The controller of the power converter employs the monitor signal to maintain efficiency and stability of the LED driver over an extended range of AC input voltage. The instantaneous voltage of the rectified signal is divided-down, and the peak value of the divided-down rectified signal is captured and stored on one or more capacitive elements. In another aspect, the peak voltage stored on one or more capacitive elements is less than 100 Volts.

An LED electrical power driver, comprising:

a rectifier having a first input node and a second input node and a first output node and a second output node, wherein an Alternating Current (AC) input signal is provided across the first and second input nodes, and wherein a rectified signal is provided by the rectifier across the first and second output nodes;
a power converter circuit having a first input node, a second input node, and a third input node, wherein the rectified signal is provided across the first and second input nodes of the power converter circuit;
and
a rectified voltage monitor electrically coupled to the first, second, and third input nodes of the power converter circuit, the rectified voltage monitor comprising:
a voltage divider and peak detection circuit configured to divide the rectified signal by a predetermined factor to generate a divided-down rectified signal and detect a signal indicative of a peak voltage of the divided-down rectified signal;
an electrical switching element having a control node, a first output node coupled to the second input node of the power converter circuit, and a second output node, wherein the signal indicative of the peak voltage of the divided-down rectified signal is communicated to the control node, wherein the electrical switching element is substantially conductive when the signal indicative of the peak voltage is greater than a first predetermined threshold value, and wherein the electrical switching element is substantially non-conductive when the signal indicative of the peak voltage is less than a second predetermined threshold value;
and
a voltage divider circuit including a first resistive element coupled between the first and third input nodes of the power converter circuit, a second resistive element coupled between the third input node of the power converter circuit and the second output node of the electrical switching element, and a third resistive element coupled between the third input node of the power converter circuit and the second input node of the power converter circuit.

5 more elements

Abstract

Claims20