A power supply is configured to limit its output power, converting an input voltage on a primary side into a bus voltage on a secondary side. A current-sense resistor detects a bus current output from the power supply to provide a current-sense signal. A bus switch is electrically connected to a secondary winding on the secondary side, configured to selectively supply power to the bus voltage. A power delivery controller controls the bus switch in response to the current-sense signal and a power detection signal on the secondary side. The power delivery controller provides a power threshold in response to the bus voltage, compares the power detection signal with the power threshold, and turns off the bus switch to stop supplying power to the bus voltage if the power detection signal exceeds the power threshold, thereby limiting the output power of the power supply.

An example method may include generating an alternating current (AC) output at a power source within a borehole in a subterranean formation. An electrical component may receive a direct current (DC) output from a converter circuit coupled to the power source and the electrical component. One or more measurements corresponding to the power source, the converter circuit, the electrical component, or a protection circuit coupled to the converter circuit may be received. Blocking devices within the protection circuit may be selectively caused to block current flow in the converter circuit based, at least in part, on the one or more received measurements.

Methods, systems, and devices for protecting a wireless power transfer system. One aspect features a sensor network for a wireless power transfer system. The sensor network includes a differential voltage sensing circuit and a current sensing circuit. The differential voltage sensing circuit is arranged within a wireless power transfer system to measure a rate of change of a voltage difference between portions of an impedance matching network and generate a first signal representing the rate of change of the voltage difference. The current sensing circuit is coupled to the differential voltage sensing circuit and configured to calculate, based on the first signal, a current through a resonator coil coupled to the wireless power transfer system.

One general aspect includes methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for fault protection of a bidirectional wireless power transfer system. The method includes the actions of detecting, by control circuitry of a wireless power transfer device, a fault for the bidirectional wireless power transfer system. Identifying an operating personality of the wireless power transfer device and a hardware configuration of the wireless power transfer device. Identifying, in response to detecting the fault and based on the operating personality and the hardware configuration, protection operations for protecting the wireless power transfer device from the fault. Controlling operations of the wireless power transfer device according to the protection operations. Other implementations of this aspect include corresponding systems, circuitry, controllers, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.

A secondary circuit device including a secondary coil for transmitting and/or receiving magnetic energy of a magnetic field and converting the magnetic energy into electrical energy, a transmission unit for transmitting the electrical energy, a detection unit, and a damper circuit, wherein the magnetic field is generated by a primary coil of a primary circuit device; the transmission unit has an inlet for connecting the secondary coil; the transmission unit has an outlet for providing the electrical energy as voltage and/or current; the detection unit is connected to the inlet and/or the outlet of the energy transmission unit, in order to detect an overvoltage at the inlet and/or the outlet; and, when the overvoltage is detected, the detection unit is configured to influence the magnetic field in the secondary coil via the damper circuit such that a current jump and/or a voltage jump is brought about in the primary coil.

A device includes a rectifier connected to a receiver coil, a first overvoltage protection apparatus connected between inputs of the rectifier and ground, and a second overvoltage protection apparatus connected between an output of the rectifier and ground, wherein in an overvoltage event, the first overvoltage protection apparatus and the second overvoltage protection apparatus are controlled based upon a comparison between a switching frequency of the device and a predetermine frequency threshold.

An integrated circuit includes a voltage regulating circuit in the form of only one transistor, or a group of several transistors in parallel, that are connected between first and second terminals configured to be coupled to an antenna. A control circuit operates to make the voltage regulating circuit inactive when a pulse generated by an electrostatic discharge event appears at one of the first and second terminals, regardless of the direction of flow of the pulse between the first and second terminals. An electrostatic discharge circuit is further provided to address the electrostatic discharge event.

A device comprises a rectifier configured to convert an alternating current voltage into a direct current voltage, a first overvoltage protection apparatus connected to inputs of the rectifier and a second overvoltage protection apparatus connected to an output of the rectifier, wherein the first overvoltage protection apparatus and the second overvoltage protection apparatus are controlled based upon a switching frequency of the device.

The present disclosure relates to a device including a rectifying bridge including: a branch connected between first and second nodes; another branch including first and second MOS transistors series-connected between the first and second nodes and having their sources coupled together; a resistor connecting the gate of the first transistor to the second node; another resistor connecting the gate of the second transistor and the first node; and for each transistor, a circuit including first and second terminals respectively connected to the drain and to the gate of the transistor, and being configured to electrically couple its first and second terminals when a voltage between the first terminal of the circuit and the first terminal of the other circuit is greater than a threshold of the circuit.

One or more embodiments relate to a control circuit for an input filter circuit in a switch mode power supply comprising a power switch and a switch controller to control the power switch to provide a regulated output voltage and current to a load. The control circuit, also referred to as a filter control circuit, can be used to detect a high voltage surge at its input and disconnect a capacitor in the input filter circuit from an input return, thereby protecting the input filter capacitor and the SMPS from damage. According to certain aspects, the control circuit can be integrated with the switch controller. Additionally, the control circuit can provide power to the switch controller at start-up.