Abstract: A circuit includes a detector configured to detect a state of a power supply including an energy storage component and to generate a control signal responsive to the state of the power supply, a dissipating component, and a switch configured to controllably couple the dissipating component to the energy storage component in response to the control signal output by the detector. Methods of operating a power supply including an energy storage component and a dissipating component are disclosed. The methods include monitoring the power supply to determine if the power supply may be active, and, in response to determining that the power supply may be inactive, coupling the dissipating component to the energy storage component to dissipate energy from the energy storage component.

Abstract: A circuit for detecting fault conditions in a supply circuit includes a monitoring circuit and a comparator circuit. The monitoring circuit is operable to output a detection signal related to a control signal for the switched mode power supply. The control signal may be configured to operate at least one switch of the supply circuit between alternating activated and deactivated states to supply power to a load. The comparator circuit is operable to compare the detection signal to a range defined by first and second thresholds and output a fault signal according to a relationship of the detection signal to the range over a time period. Related methods of operation are also discussed.

Abstract: A lighting apparatus includes a string with a plurality of serially-connected light emitting device sets, each set comprising at least one light emitting device. The apparatus further includes at least one controllable bypass circuit configured to variably bypass current around at least one light emitting device of a set of the plurality of light emitting device sets responsive to a control input. The control input may include, for example, a temperature input, a string current sense input and/or an adjustment input. The control input may be varied, for example, to adjust a color point of the string.

Abstract: A lighting apparatus includes a string of serially-connected light emitting devices and a bypass circuit coupled to first and second nodes of the string and configured to variably conduct a bypass current around at least one of the light-emitting devices responsive to a temperature and/or a total current in the string. In some embodiments, the bypass circuit includes a variable resistance circuit coupled to the first and second nodes of the string and configured to variably conduct the bypass current around the at least one of the light-emitting devices responsive to a control voltage applied to a control node and a compensation circuit coupled to the control node and configured to vary the control voltage responsive to a temperature and/or total string current.

Abstract: Lighting is controlled by receiving an input signal, determining whether the input signal is an AC signal or a DC signal and generating a dimming command signal based on the determination of whether the input signal is an AC signal or a DC signal. For example, determining whether the input signal is an AC signal or a DC signal may include generating an average signal indicative of an average duty cycle of the input signal and determining whether the average signal meets a predetermined criterion.