An LED light fixture includes a housing, a controller circuit having direct current (DC) and alternating-current (AC) power inputs, a direct-current (DC) power supply unit (PSU) connected to the controller circuit, an alternating-current (AC) PSU connected to the controller circuit, and at least two groups of light emitting diodes (LEDs) operable to emit light, wherein each group includes at least one LED of a first type and at least one LED of a second type. In some embodiments, when the LED light fixture operates in a security mode the controller prevents power from flowing to the AC PSU and allows power to flow to the DC PSU to power only the first type of LEDs of the at least two groups of LEDs to emit a security light.

Systems, methods, and apparatus for a circuit with power factor correction (PFC) are disclosed. In one or more embodiments, the disclosed method comprises providing, by a single-stage power converter, a delay in phase between a peak current command and a rectified input voltage such that a phase of a transformer current intentionally lags behind a phase of the rectified input voltage to maintain a power factor (PF) level and a total harmonic distortion (THD) level for the single-stage power converter. In one or more analog embodiments, a resistor and a capacitor are implemented into a conventional single-stage power converter to provide the delay in phase between the peak current command and the rectified input voltage. In one or more digital embodiments, a controller within a conventional single-stage power converter exclusively provides the delay in phase between the peak current command and the rectified input voltage.

Systems, methods, and apparatus for a circuit with power factor correction (PFC) are disclosed. In one or more embodiments, the disclosed method comprises providing, by a single-stage power converter, a delay in phase between a peak current command and a rectified input voltage such that a phase of a transformer current intentionally lags behind a phase of the rectified input voltage to maintain a power factor (PF) level and a total harmonic distortion (THD) level for the single-stage power converter. In one or more analog embodiments, a resistor and a capacitor are implemented into a conventional single-stage power converter to provide the delay in phase between the peak current command and the rectified input voltage. In one or more digital embodiments, a controller within a conventional single-stage power converter exclusively provides the delay in phase between the peak current command and the rectified input voltage.

Systems, methods, and apparatus for a circuit with power factor correction (PFC) are disclosed. In one or more embodiments, the disclosed method comprises providing, by a single-stage power converter, a delay in phase between a peak current command and a rectified input voltage such that a phase of a transformer current intentionally lags behind a phase of the rectified input voltage to maintain a power factor (PF) level and a total harmonic distortion (THD) level for the single-stage power converter. In one or more analog embodiments, a resistor and a capacitor are implemented into a conventional single-stage power converter to provide the delay in phase between the peak current command and the rectified input voltage. In one or more digital embodiments, a controller within a conventional single-stage power converter exclusively provides the delay in phase between the peak current command and the rectified input voltage.

The present invention relates generally to systems and methods for providing emergency lighting in an area. More specifically, the present invention relates to systems and methods for providing reliable power to emergency lighting, monitoring the emergency lighting to insure proper operation and function, and effective, efficient notification of users of status and error conditions of the emergency lighting.

An electronic circuit for protecting a load against over-voltage is disclosed. The electronic circuit comprises an input port for receiving a voltage and an output port for feeding the voltage to the load. The electronic circuit further comprises a switching unit arranged to switch on and off the voltage from the input port. Moreover, the electronic circuit comprises a capacitive component arranged to receive the voltage when the switching unit is switched on and is otherwise arranged to feed voltage to the output port. Furthermore, the electronic circuit comprises a comparing unit configured to control the switching unit to be switched off when a value at the output port exceeds a first threshold; and to control the switching unit to be switched on when the value is below a second threshold.

Lighting power supply system (1) including a mains input converter (11) operable to provide power, a controller (17) operable to control at least one element of the lighting system, a controller bus (26) and a controller interface (25) operable to provide control signals from the bus to the lighting system. An auxiliary converter (43) powers the lighting system from the bus and it may allow the controller to continue to be powered when the mains input is absent and an emergency battery (19) is depleted.