A transient voltage suppression device includes at least one diode string, a power clamp device, at least one first bypass diode, and at least two second bypass diodes. The diode string is coupled between a power terminal and a common bus and coupled to an input output (I/O) port. The power clamp device is coupled between the power terminal and the common bus. The first bypass diode is coupled between the common bus and a ground terminal The second bypass diodes are coupled in series, coupled between the common bus and the ground terminal, and coupled to the first bypass diode in reverse parallel. Alternatively, the first bypass diode and the second bypass diodes are replaced with at least one bi-directional electrostatic discharge (ESD) device.

In one embodiment, an overvoltage protection device (100) may include a crowbar device (106), where the crowbar device (106) includes a first crowbar terminal (115), the first crowbar terminal (115) connected with a first external voltage line (102). The overvoltage protection device (100) may further include a transient voltage suppression (TVS) device (108), where the TVS device (108) includes a second TVS terminal (121), the second TVS terminal (121) connected with a second external voltage line (104). The crowbar device (106) and the TVS device (108) may be arranged in electrical series between the first crowbar terminal (115) and the second TVS terminal (121).

Methods and apparatuses for protecting a low voltage (LV) circuit implemented with LV transistors are presented. Protection is provided via a protection circuit operating in a high voltage domain defined by a varying supply voltage and a reference ground. The protection circuit generates high side, V.sub.H, and low side, V.sub.L, voltages to the LV circuit, while protecting the LV circuits from high voltage and maintaining a minimum difference voltage, V.sub.H−V.sub.L. The protection circuit generates the difference voltage based on a voltage across a resistor of a resistor ladder that is coupled between the varying supply voltage and the reference ground. The protection circuit includes a clamp circuit that limits the minimum difference voltage for low values of the supply voltage. The protection circuit generates the difference voltage according to a nonlinear transfer function of the supply voltage that includes two linear segments having different slopes and a nonlinear segment that provides a continuous and smooth transition between the two linear segments.

An electronic circuit includes a diode configured to carry a surge current generated by switching of a first transistor, a capacitor connected between a cathode of the diode and a control electrode of the first transistor, and a first variable impedance circuit configured to vary an impedance between the control electrode of the first transistor and a first reference voltage node according to the surge current flowing to the diode.

Disclosed is a leakage current measuring device for a grid protection system protecting a power distribution or transmission grid from damage in case of a power surge, the grid protection system including a disconnector device and a surge arrester connected in series along a grounding path, the grounding path connecting a phase of a power distribution or transmission grid through the surge arrester and the disconnector device to ground, the disconnector device being configured for being activated in case of an overload condition, thereby disconnecting the surge arrester. The leakage current measuring device includes a leakage current sensor for measuring a leakage current I.sub.L flowing along the grounding path, the leakage current I.sub.L being indicative of the electrical connection status of the disconnector device. The electrical connection status is one of an activated and an inactivated status of the disconnector device.

A high frequency data recorder (“HFDR”) can include a first set of contacts, on a first side of the HFDR, that are pluggable into a first meter receptacle of a meter box, wherein the first meter receptacle provides a connection to a power supply and a connection to a load. The HFDR also includes a second set of contacts, on a second side of the HFDR, that form a second meter receptacle. The second meter receptacle provides another connection to the power supply and another connection to the load. The HFDR can further include a processor that accesses a non-transitory machine readable memory that stores instruction that when executed cause the processor to passively measures current downstream from the meter box. The HFDR still further includes a wireless transceiver that wirelessly transmits data characterizing the measured current.

A protection circuit, comprising: a transient suppression circuit, configured to suppress a transient voltage; and a short-circuit protection circuit connected between the transient suppression circuit and a ground terminal, wherein when the transient suppression circuit is shorted out and the transient voltage is a protection voltage, the short-circuit protection circuit disconnects a loop where the transient suppression circuit is located. The short-circuit protection circuit has a turned-on state and a turned-off state; the short-circuit protection circuit is in a turned-on state when the transient suppression circuit is shorted out and the transient voltage is greater than the protection voltage; and the short-circuit protection circuit is in a turned-off state when the transient suppression circuit is shorted out and the transient voltage is a protection voltage.

A surge protective device (SPD) circuit system for providing overvoltage protection to an electrical power circuit includes a PCB assembly, an SPD module, and an SPD monitoring system. The PCB assembly selectively mountable on the PCB includes a PCB and a remote signal (RS) PCB contact on the PCB. The SPD module includes an overvoltage clamping element and an RS spring contact including an RS contact portion. When the SPD module is mounted on the PCB and the electrical power circuit is connected to the PCB: the PCB electrically connects the SPD module to the circuit and the overvoltage clamping element provides overvoltage protection to the circuit; the RS contact portion engages the RS PCB contact; the RS spring contact is elastically deflected and persistently loads the RS contact portion against the RS PCB contact; and the RS spring contact is electrically connected to the SPD monitoring system via the RS PCB contact.

The present disclosure provides a circuit including a coaxial cable interface, a data module, a power module, a power signal transmission branch, and a data signal transmission branch. The data module may receive or output a data signal. The power module may receive or output a power signal. The power signal transmission branch may be electrically coupled between the coaxial cable interface and the power module, and may include an inductor that allows the power signal to pass. The data signal transmission branch may be electrically coupled between the coaxial cable interface and the data module, and may include a capacitor that allows the data signal to pass and a first electrical surge protection circuit. The first electrical surge protection circuit may release a surge current on the data signal transmission branch.

An apparatus includes a surge protection device, a current sensor configured to sense a current through the surge protection device, and a surge discriminator circuit coupled to the current sensor and configured to discriminate among a plurality of surge levels for the surge protective device responsive to the sensed current. The current sensor may include a current transformer configured to generate a secondary current responsive to the sensed current and the surge discriminator circuit may be configured to discriminate among a plurality of surge levels responsive to the generated secondary current.