A reverse polarity protection device includes a protection unit, a detection unit, and a control unit electrically connected between a power supply device and a load device. The detection unit is electrically connected to the power supply device for detecting the polarity of an output signal of the power supply device, and the control unit is electrically connected to the detection unit and the protection unit. The detection unit outputs a detection signal to the control unit according to a detection result of the polarity of the output signal. If the detection signal shows that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and load device to stop transmitting the output signal of the power supply device to the load device and achieve a reverse polarity protection effect of the load device.

A terminal protection voltage detector circuit is provided for protecting a terminal block having output terminals in a power supply apparatus. A current detector detects output currents flowing from the power supply apparatus to loads via output terminals, and a first comparator configured to compare a sum of the detected output currents with a predetermined first threshold and output a first comparison result signal when the sum of output currents is larger than or equal to the first threshold. A second comparator configured to compare a maximum value of detected output currents with a predetermined second threshold and output a second comparison result signal when the maximum value is equal to or larger than the second threshold. A current stop circuit stops a current from flowing from the power supply apparatus to the output terminals based on the first or second comparison result signal.

A power supply comprises voltage regulation circuitry, a load-share controller, and overcurrent protection circuitry. The voltage regulation circuitry is configured to output a regulated voltage. The load-share controller is configured to control the voltage regulation circuitry to adjust the regulated voltage responsive to a load-share voltage signal (LSV) that indicates an amount of load current being delivered to a load. The overcurrent protection circuitry is configured to selectively couple the regulated voltage to the load. When the load current exceeds a threshold current, the overcurrent protection circuitry is configured to decouple the regulated voltage from the load. While the regulated voltage is decoupled from the load, and when the LSV signal indicates that load current is being delivered to the load by a different power supply, the overcurrent protection circuitry is configured to recouple the regulated voltage to the load.

A CCM-based fly-back switching power supply circuit includes: a constant current control circuit, a sampling circuit and a peak current control circuit, wherein a sampling circuit is configured to sample the ON-time of the secondary coil to obtain its duty cycle signal D_SEC, and send the signal to a constant current control circuit; a constant current control circuit is configured to receive the duty cycle signal D_SEC, generate a voltage signal CAC from the duty cycle signal D_SEC and the preset reference voltage signal VREF, convert the voltage signal CAC and the peak current control signal VCST from the peak current control circuit into time signals, and conform a comparison on the time signals to output an adjustment signal CCOUT which is used to initiatively adjust the value of the peak current control signal VCST to cause the fly-back switching power supply circuit output a constant current.

A protection circuit for connecting and disconnecting to a DC power source, and a DC operated device including such a protection circuit. The protection circuit has input terminals for receiving power from a DC power source and output terminals for providing power to a DC operated device; a first stage with a voltage measurement circuit coupled between the input terminals; and a second stage following the first stage including a pre-charge control circuit. The protection circuit further includes a digital controller arranged for controlling activating and de-activating a local PSU for supplying power to electronics of the DC operated device. The digital controller is arranged for measuring a voltage of the voltage measurement circuit and de-activating the local PSU when detecting a voltage drop on the first input terminal that exceeds a predetermined threshold dip and/or threshold slope.

In some examples, this disclosure describes a method for detecting a fault in an electrical power system comprising a bus connected between a first solid state power converter and a second solid state power converter. The method includes receiving, at a controller of the electrical power system, a first signal indicating a current at a source side of the first solid state power converter, wherein the source side of the first solid state power converter is connected to a power source of the electrical power system. The method also includes receiving, at the controller, a second signal indicating a current at the bus and determining, by the controller, that a fault occurred in the electrical power system based on the first signal and further based on the second signal. The method further includes controlling the first solid state power converter in response to determining that the fault occurred.

An isolated switched-mode power converter converts power from an input source into power for an output load. Power switches within a primary-side power stage control the amount of power input to the power converter and, ultimately, provided to the output load. A digital controller on the secondary side of the power converter generates signals to control the power switches. This controller also senses a rectified voltage on the secondary side of the power converter and uses this sensed voltage to detect fault conditions of the primary side. For example, the sensed rectified voltage is used to detect undervoltage or overvoltage conditions of the input power source of the power converter, or faulty power switches within the primary-side power stage.

The present disclosure provides a method for controlling a surgical instrument. The method includes connecting a power assembly to a control circuit, wherein the power assembly is configured to provide a source voltage, energizing, by the power assembly, a voltage boost convertor circuit configured to provide a set voltage greater than the source voltage, and energizing, by the voltage boost convertor, one or more voltage convertors configured to provide one or more operating voltages to one or more circuit components.

An arc detection device includes: a low-impedance circuit connected between a node on wiring connecting the positive electrode of a DC/DC converter and a plurality of DC/DC converters, extending from the positive electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters and a node on wiring connecting the negative electrode of the DC/DC converter and the plurality of DC/DC converters, extending from the negative electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters; an electric current detector that detects an electric current flowing through the low-impedance circuit; and an arc determiner that determines, on the basis of the electric current detected by the electric current detector whether an electric arc has occurred.

An arc detection device includes a voltage detector connected between a first wire and a second wire to detect a voltage between the first wire and the second wire, the first wire connecting a positive electrode of a DC/DC converter and a plurality of DC/DC converters and branching from the positive electrode of the DC power source into the plurality of DC/DC converters, the second wire connecting a negative electrode of the DC/DC converter and the plurality of DC/DC converters and branching from the negative electrode of the DC/DC converter into the plurality of DC/DC converters; and an arc determiner that determines an occurrence of an arc based on the voltage detected by the voltage detector.