A lighting relay panel may include lower-cost features or components related to improved safety and reliability. In some cases, the relay panel includes a power supply capable of protecting the panel from high-voltage and high-current transients. A microcontroller may determine a power interruption based on a zero-cross signal received from the power supply, and may also configure latching relays during the interruption. In some implementations, the relay panel includes a relay sense circuit that is capable of receiving actuation signals from multiple relays connected to different phases of a power signal, and the microcontroller may synchronize or repeat the actuations based on a signal from the relay sense circuit. The microcontroller may generate relay addresses based on the relay positions within the relay panel. In some cases, the relay panel may include isolation circuits that are capable of providing an isolated control signal having an improved voltage range.

A system and method for detecting and isolating an electromagnetic pulse (EMP) along first phase, second phase, and third phase electrical lines electrically connected to a monitored infrastructure so as to protect the monitored infrastructure, the method for detecting and isolating includes a phase unit receiving electric signal data from a sensor electrically connected individually to each of the first phase, second phase, and third phase electrical lines, respectively, upstream of and associated with the monitored infrastructure. The method includes determining if the received electric signal data associated with the respective electrical line is indicative of an E1 component of an EMP and, if so, actuating an isolation subsystem in less than 300 nanoseconds to electrically isolate the respective electrical line against electrical communication with the monitored infrastructure.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

A surge protection device includes a surge protection circuit, a controller, and a wireless module. The surge protection circuit has a plurality of surge protection elements, receives a power source and correspondingly generates a sampling signal according to the power source. The controller compares a representative voltage value of the power source corresponding to the sampling signal with a first reference value to determine a using state of the surge protection circuit. The wireless module correspondingly transmits the using state to a remote server.

A surge protection device includes a surge protection circuit, a controller, and a wireless module. The surge protection circuit has a plurality of surge protection elements, receives a power source and correspondingly generates a sampling signal according to the power source. The controller compares a representative voltage value of the power source corresponding to the sampling signal with a first reference value to determine a using state of the surge protection circuit. The wireless module correspondingly transmits the using state to a remote server.

A protection circuit is provided. A control circuit receives an input voltage. In a case that the input voltage is lower than a negative threshold voltage, the control circuit outputs a first control voltage to a surge bleeder circuit through a first output end of the control circuit, to control the surge bleeder circuit to discharge the input voltage and output a first bleeder current. In a case that the input voltage is higher than a positive threshold voltage, the control circuit outputs a second control voltage to the surge bleeder circuit through a second output end of the control circuit, to control the surge bleeder circuit to discharge the input voltage and output a second bleeder current.

An irrigation controller comprising a housing, a control circuit having a processor and a memory, the control circuit configured to store and execute an irrigation schedule, an input connector configured to be coupled to an alternating current (AC) power supply and receive an AC power signal having a first voltage level, a transformer disposed at least partially in the housing, the transformer having a primary side and a secondary side, wherein the primary side is coupled to the input connector, a resettable fuse disposed at least partially in the housing, the fuse being electrically coupled in series between the input connector and the primary side of the transformer, driver circuitry disposed in the housing and electrically coupled to the secondary side of the transformer, and wherein the driver circuitry is coupled to the control circuit, and an output connector coupled to the driver circuitry.

A power distribution system includes a solid state power controller (SSPC). The SSPC includes a microcontroller having at least one voltage sense input. The microcontroller is configured to selectively allow a current through the SSPC in response to a common mode voltage to ground and/or a SSPC differential voltage meeting or exceeding a respective pre-determined threshold. A method of operating a SSPC includes determining whether at least one of a common mode voltage to ground or a SSPC differential voltage meet or exceed a respective pre-determined threshold. The method includes selectively allowing a current through the SSPC in response to at least one of the common mode voltage to ground or the SSPC differential voltage meeting or exceeding the respective pre-determined threshold.

A power distribution system includes a solid state power controller (SSPC). The SSPC includes a microcontroller having at least one voltage sense input. The microcontroller is configured to selectively allow a current through the SSPC in response to a common mode voltage to ground and/or a SSPC differential voltage meeting or exceeding a respective pre-determined threshold. A method of operating a SSPC includes determining whether at least one of a common mode voltage to ground or a SSPC differential voltage meet or exceed a respective pre-determined threshold. The method includes selectively allowing a current through the SSPC in response to at least one of the common mode voltage to ground or the SSPC differential voltage meeting or exceeding the respective pre-determined threshold.