A protection circuit includes: a high-side switch connected to a power terminal to which a predetermined power supply voltage VBB is supplied from an onboard battery; and an NMOS transistor MT1 connected to the high-side switch and configured to prevent an electrical conduction to the high-side switch when the onboard battery is reverse-connected to the power terminal, wherein a semiconductor integrated circuit is protected from a breakdown due to the reverse connection of the external power supply. A semiconductor integrated circuit apparatus includes the above-mentioned protection circuit configured to protect a semiconductor integrated circuit connected between the power terminal and the ground terminal, from an electro-static discharge breakdown. The protection circuit is connected to the clamp circuit unit inserted between the power terminal and the ground terminal, and is configured to protect the clamp circuit unit from a breakdown when the external power supply is reverse-connected.

A protector is provided on an electric wire that is connected to first and second in-vehicle devices, and protects the first and second in-vehicle devices from a DC overcurrent that flows bi-directionally through the electric wire. The protector includes a thermal fuse, which is provided at a midpoint of the electric wire, and a current restrictor for restricting a current that flows therethrough, in accordance with the direction in which the current flows through the electric wire, the current restrictor being connected in parallel to the thermal fuse.

A host electronic device may be coupled to an accessory electronic device. The host device and the accessory device may be connected via power supply lines and user data lines. If the host and accessory devices are improperly connected or if the accessory device is exposed to an incorrect voltage environment, the internal circuitry on the accessory device can be damaged. The accessory device may therefore include a reverse voltage protection circuit that can help prevent a large amount of current from inadvertently flowing into the accessory device. The protection circuit may include a low-side-enabled reverse current protection switch coupled between the external and internal ground terminals and also a single low-drop switch coupled to each of the user data lines. The low-drop switch will be activated whenever the voltage at the external ground terminal exceeds the voltage at the data line to help deactivate low-side-enabled reverse current protection switch.

A backflow preventing device includes a backflow preventing element connected between a power source and a load, for preventing a backflow of a current from the load side to the power source side, a commutation device configured to perform a commutation operation of causing a current to flow through an other path connected in parallel to the backflow preventing element, and a controller configured to change a pulse width of a commutation drive signal for controlling the commutation device to perform the commutation operation based on a current flowing through the backflow preventing element, and transmitting the commutation drive signal having the changed pulse width to the commutation device. The controller transmits the pulse to the commutation device only for a necessary time period so that the commutation device performs the commutation operation, to thereby reduce electric power relating to the commutation operation not contributing to the power conversion.

A reverse current protection circuit for a switch circuit includes a reverse current control circuit and an enable/disable circuit coupled to the reverse current control circuit. The reverse current control circuit is coupled to an input terminal and an output terminal of the switch circuit, and disconnects the output terminal of the switch circuit from the input terminal of the switch circuit when an output voltage of the switch circuit is higher than a first predetermined voltage. The enable/disable circuit disables the reverse current control circuit for a first predetermined time period when the output voltage of the switch circuit becomes lower than the first predetermined voltage after being higher than the first predetermined voltage, and enables the reverse current control circuit after the first predetermined time period.

An electricity backfeed protection assembly is beneficially installed between a main circuit breaker panel of a structure or dwelling, and a utility meter measuring electricity delivered to the structure or dwelling by a utility provider or other primary power source. The electricity backfeed protection assembly includes a contactor having a coil. A contact protector device is electrically connected to the coil of the contactor. The electrical backfeed protection assembly automatically prevents electricity from a secondary power source (including, without limitation, a portable generator) from backfeeding into supply lines of a primary power source (such as utility lines or equipment).

A power generation and control system is easily installed in a consumer household, a business, or and end-user establishment for generating power and preventing power from flowing to a power grid from a consumer circuit during a power outage. A communications transceiver is adapted to transmit an enabling signal for enabling power generation only after the control system has been installed. The control system can be adapted to replace an existing circuit breaker in a household circuit box and prevents power from traveling from consumer power generators to the grid during a power outage. In the same manner that end-users can add appliances to existing circuits, end-users can easily add additional power generation devices without hiring a professional electrician and without worrying about causing harm to utility workman during power outages.

A transformer assembly comprises at least one transformer having a core. A primary winding is positioned on a first portion, a secondary winding is positioned on a second portion of the core. A neutral winding may be positioned on a third portion of the core. The secondary winding may receive an induced flux produced by an earth surface potential (ESP) via a system ground and/or receive an induced zero sequence flux produced by a non-linear load. The neutral winding may be configured to provide a mitigating flux to the secondary winding. The transformer may also be used as a filter for either GIC or triplen harmonic mitigation. In this case, the primary windings receive the zero sequence current (GIC or triplen harmonics) and the flux may be cancelled in neutral winding such that the zero sequence currents circulate between the zero sequence source and the filter transformer.

Safety devices, systems, and methods for automatically interrupting power from electricity sources in a vehicle, such as a vehicle battery to prevent post car collision fires. A housing having an interior circumferential chamber formed between an upper section and a lower section, and a weighted metal ball positioned between upper and lower compressed springs in a midportion of the interior chamber so that an electrical path can pass through the housing. The interior chamber tapers down from interior walls about the midportion of the chamber to outer interior portions of the housing, the housing can be mounted to the positive terminal of a vehicle battery, where a collision causes the spring compressed ball to become dislodged breaking the electrical path interrupting electricity from the vehicle battery, and the ball becomes wedged inside the tapering down interior walls inside of the housing.

An electrical power supply system is equipped with a first electrical power supply circuit that supplies an electrical power output from a first electrical power conversion device to a first load device, a second electrical power supply circuit that supplies an electrical power output from a second electrical power conversion device to a second load device, and a first connection circuit that is capable of connecting the first electrical power supply circuit and the second electrical power supply circuit, wherein, in the case of supplying the electrical power output from the second electrical power conversion device to the first load device, the electrical power output from the second electrical power conversion device is caused to be reduced, and thereafter, the first electrical power supply circuit and the second electrical power supply circuit are connected.