The analog signal detecting circuit comprises a reference voltage generator that outputs a plurality of reference voltages, the number of the reference voltages being varied depending on a voltage width between a minimum voltage value and a maximum voltage value of an analog signal; a plurality of comparators that compares a voltage of the analog signal with each of the plurality of reference voltages output from the reference voltage generator; a plurality of pulse generators that outputs a plurality of pulse signals having widths among the plurality of pulse signals varied depending on a frequency of the analog signal; and a combiner circuit section that outputs the pulse signals from the plurality of pulse generators by summing up.

The analog signal detecting circuit comprises a reference voltage generator that outputs a plurality of reference voltages, the number of the reference voltages being varied depending on a voltage width between a minimum voltage value and a maximum voltage value of an analog signal; a plurality of comparators that compares a voltage of the analog signal with each of the plurality of reference voltages output from the reference voltage generator; a plurality of pulse generators that outputs a plurality of pulse signals having widths among the plurality of pulse signals varied depending on a frequency of the analog signal; and a combiner circuit section that outputs the pulse signals from the plurality of pulse generators by summing up.

A controller includes a tracking regulator having a reference voltage input and a voltage output and configured to regulate the voltage output to the reference voltage input. The controller is configured to, in response to a short to ground of the voltage output, electrically couple the reference voltage input to the voltage output.

In a three-level chopper apparatus, a protection switch circuit is controllable to change a current pathway through which an overvoltage is applied to a second capacitor or a first capacitor to a current pathway through which no overvoltage is applied to the second capacitor or the first capacitor.

Techniques are disclosed relating to electrical safety systems that may be useful, for example, in electromagnetic geophysical prospecting. Electromagnetic streamer systems often include a number of electrical loads in series that are powered by a constant-current power supply unit. Known techniques for detecting electrical faults have various drawbacks in such an arrangement. Embodiments of this disclosure may be used to mitigate some or all of such drawbacks.

A detection circuit includes: a first switch, a second switch, a first detection resistor and a second detection resistor, wherein the first switch and the first detection resistor are coupled in series to form a first branch, a first end of the first branch is electrically connected with a positive bus of the photovoltaic inverter and a second end of the first branch is electrically connected with a ground; and the second switch and the second detection resistor are coupled in series to form a second branch, a first end of the second branch is electrically connected with a negative bus of the photovoltaic inverter and a second end of the second branch is electrically connected with the ground.

An arc protection system for an electrical enclosure having an electrical component positioned in an interior thereof. The system includes two busbars and at least one arc routing device positioned in the interior and an arc containment device defining a cavity and including an electrode assembly positioned within the cavity, wherein the electrode assembly is electrically coupled to the two busbars. The system also includes at least one arc routing device having a first end proximate the electrical component and a second end proximate the arc containment device. The at least one arc routing device is operative to i) attract arc plasma generated during an arc event at the electrical component, and ii) transport the arc plasma to the arc containment device, wherein the arc containment device is configured to transfer electrical energy of the arc plasma to an exterior of the electrical enclosure.

An arc protection system for an electrical enclosure having an electrical component positioned in an interior thereof. The system includes two busbars and at least one arc routing device positioned in the interior and an arc containment device defining a cavity and including an electrode assembly positioned within the cavity, wherein the electrode assembly is electrically coupled to the two busbars. The system also includes at least one arc routing device having a first end proximate the electrical component and a second end proximate the arc containment device. The at least one arc routing device is operative to i) attract arc plasma generated during an arc event at the electrical component, and ii) transport the arc plasma to the arc containment device, wherein the arc containment device is configured to transfer electrical energy of the arc plasma to an exterior of the electrical enclosure.

Implementations of ground fault circuit interrupter (GFCI) self-test circuits may include: a current transformer coupled to a controller, a silicon controlled rectifier (SCR) test loop coupled to the controller, a ground fault test loop coupled to the controller, and a solenoid coupled to the controller. The SCR test loop may be configured to conduct an SCR self-test during a first half wave portion of a phase and the ground fault test loop may be configured to conduct a ground fault self-test during a second half wave portion of a phase. An SCR may be configured to activate the solenoid to deny power to a load upon one of the SCR self-test or the ground fault self-test being identified as failing.

Aspects of the disclosure provide for a circuit. In some examples, the circuit includes a first current source having a terminal coupled to a first node and a second terminal, a first switch coupled between the second terminal of the first current source and a second node, a first resistor coupled between the second node and a ground terminal, a second current source having a terminal coupled to the first node and a second terminal, a second switch coupled between the second terminal of the second current source and a third node, a second resistor coupled between the third node and the ground terminal, a third current source having a terminal coupled to the first node and a second terminal, a third switch coupled between the second terminal of the third current source and a fourth node, and a third resistor coupled between the fourth node and the ground terminal.