The invention relates to a control circuit for protecting an electrostatic spray-coating apparatus, which has a high-voltage supply, against spark discharge. The control circuit has a disconnection device for automatically disconnecting the high-voltage supply, and has a device for detecting abnormal operation of the high-voltage supply. The device for detecting abnormal operation of the high-voltage supply is designed to monitor at least one parameter which is characteristic of the operation of the high-voltage supply, and to output a corresponding disconnection signal to the disconnection device when the at least one parameter which is characteristic of the operation of the high-voltage supply exceeds or falls below a predefined or predefinable limit value.

A method for detecting arc faults when charging electric battery systems or lead acid batteries, which are electrically connected in series to form a string which is supplied via a DC voltage converter. A first value corresponding to an electric voltage applied to the string and a second value corresponding to an electric current flowing through the string are generated. As a first condition, it is checked whether the first value changes by more than a first limit value within a first time window. As the second condition, it is checked whether the second value changes by more than a second limit value within a second time window. An arc is detected if the first condition and the second condition are met within a third time window. Provided also is a method for manufacturing electric battery systems, in particular lead acid batteries, as well as to a cut-off device.

A Direct Current fault protection and localization system utilizing a Rogowski coil adapted to perform current limiting on the main power line in the case of a line to line fault.

A solid-state circuit interrupter and arc prevention device (SSI/APD) is disclosed. The SSI/APD is designed to be configured in series with a mechanical circuit breaker and serves to interrupt current flowing through the circuit it is protecting upon a short circuit being detected or if an overload has persisted for an inordinate amount of time. The SSI/APD is capable of detecting and responding to faults in a matter of microseconds and detects and responds to faults on its own, without requiring the mechanical circuit breaker to trip. The mechanical circuit breaker can be optionally tripped after the SSI/APD has opened the circuit. However, the mechanical circuit breaker is tripped only after the SSI/APD has interrupted the circuit, so electrical arcing across the circuit breaker's contacts is avoided. The SSI/APD can also be reset remotely after a fault has been cleared, obviating the need for a person to be present to reset it.

The invention relates to a control circuit for protecting an electrostatic spray-coating apparatus, which has a high-voltage supply, against spark discharge. The control circuit has a disconnection device for automatically disconnecting the high-voltage supply, and has a device for detecting abnormal operation of the high-voltage supply. The device for detecting abnormal operation of the high-voltage supply is designed to monitor at least one parameter which is characteristic of the operation of the high-voltage supply, and to output a corresponding disconnection signal to the disconnection device when the at least one parameter which is characteristic of the operation of the high-voltage supply exceeds or falls below a predefined or predefinable limit value.

A system includes a first transistor having a first control input and first and second current terminals. The first current terminal couples to an input voltage node. A second transistor has a second control input and third and fourth current terminals. The third current terminal couples to the second current terminal at a first node. The fourth current terminal couples to an output voltage node. A drive circuit is configured to charge a capacitor maintain the first transistor in an off state responsive to a negative voltage on the input voltage node, and, responsive to a negative voltage on the input voltage node, to cause the charge from the capacitor to be used to turn off the first transistor. The system provides a voltage to a load coupled to the output voltage node.

In one aspect, a solid-state circuit breaker (SSCB) is provided. The SSCB is configured to generate a first output representative of a current through a current path of the SSCB. An analog fault detection circuit is coupled with first output and is configured to assert a second output in response to the current exceeding a trip current level. At least one analog-to-digital converter (ADC) is configured to generate samples of the first output, where the at least one ADC has a di/dt detection bandwidth that is less than a di/dt detection bandwidth of the analog fault detection circuit. The SSCB is further configured to disable the current path through the SSCB in response to determining, asynchronously, that either the second output is being asserted by the analog fault detection circuit or the samples indicate that the current through the current path exceeds the trip current level.

A load control apparatus for controlling a power supply to an electrical load connected to an output terminal includes an overcurrent protection circuit having a power switch through which the electrical load receives a load current and a sensor component in series with the power switch that is configured to generate a voltage drop corresponding to the current rise speed of a load current from an input terminal to the output terminal. The protection circuit includes a driver circuit configured to detect an overcurrent depending on the voltage drop generated by the sensor component and/or at the power switch, and to switch off the power switch upon detection of an overcurrent within a switch-off period. The overcurrent protection circuit can include a power supply control circuit having a sensor component adapted to measure a supply voltage notified to a control unit of the load control apparatus adapted to control power supplied to the load.

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 device comprises a solid-state power switch and a control configured to operate the power switch if at least one of a plurality of fault conditions of the device is triggered. An interface is configured to output a signal having a value selectively indicative of the triggered at least one fault condition in response to the at least one fault condition being triggered.