A control apparatus for an electro-optic element comprises a first voltage converter in connection with a power supply. The first voltage converter is configured to receive a supply voltage from the power supply and output a first voltage. A first storage capacitor is in connection with the first voltage converter and configured to store first energy at the first voltage. A second storage capacitor is configured to store second energy at a second voltage, wherein the second energy is supplied by the power supply. A driving circuit in conductive connection with the second storage capacitor and configured to supply a driving voltage to the electro-optic element. In response to a failure of the power supply, the first storage capacitor is configured to supply the first energy to a controller and the second storage capacitor is configured to supply the second energy to the driving circuit.

A protection circuit and a printed circuit board (PCB) for a terminal camera includes, in a configuration for coupling with a voice control motor (VCM), a drive circuit, a first circuit, a second circuit, a first protection system, a second protection system, and a third protection system. The first circuit and the second circuit are choke inductors or choke circuits including choke inductors, and are configured to couple to two ends of the VCM. The first protection system, the second protection system, and the third protection system are coupled to other key positions of the circuits. The devices are arranged on a top layer of the PCB, and a plurality of layers of the PCB are configured to route a signal based on design requirements.

Structurally supported electrical transient materials are disclosed. Furthermore, methods to provide structurally supported electrical transient materials are disclosed. In one implementation, a structurally supported electrical transient material includes a support structure that is at least partially covered by an electrical transient material. In one example, the support structure is a mesh material integrated at least partially in the electrical transient material.

According to one aspect, a power device is provided. The power device includes an input having at least a first connection and a second connection, and configured to be coupled to an AC power source to receive input AC power, a converter circuit coupled to the input and configured to convert an input AC voltage to a DC voltage, a load output configured to provide output power derived from the DC voltage, a rectifier circuit coupled to the input and having a first output and a second output, and a first capacitor coupled to the first output of the rectifier circuit and the second output of the rectifier circuit.

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.

An electrical wiring device including a ground fault interrupt assembly, the ground fault interrupt assembly comprising a ground fault interrupt circuit, being formed on a first printed circuit board, and a trip mechanism, the ground fault interrupt circuit being configured to detect a differential current between the line conductor and the neutral conductor and to trigger the trip mechanism to electrically decouple the plurality of line terminals from the plurality of load terminals, according to a predetermined criterion, based, at least in part, on the different current; and a USB power supply circuit being formed on a second printed circuit board disposed within the compartment, the USB power supply circuit providing to the at least one USB port, wherein the first printed circuit board and the second printed circuit board are separated by a distance within the inner compartment.

An integrated component for protecting against temporary power surges comprises a first conductive lead and a second conductive lead, each of which mounted on an electrical circuit; a gas discharge tube; a thermally protected varistor and a thermal fuse. The thermally protected varistor comprises a varistor body, a first varistor electrode and a second varistor electrode that are positioned on either side of the varistor body. The varistor body rises in temperature when the voltage imposed between the first and the second varistor electrodes exceeds a voltage threshold. An electrical connection is made via the thermal fuse.

A compensation filter and a method for activating a compensation filter are disclosed. In an embodiment a compensation filter includes an operational amplifier, a capacitive element, a first and a second resistive element and a current converter. The compensation filter is configured to attenuate a common mode interference in a critical frequency range.

A system and method for suppressing EMP-induced electrical system voltage surges due to detonation of a nuclear weapon, the EMP comprising E1, E2, and E3 component pulses. A plurality of shunting assemblies, each including MOVs, gas discharge tubes, other mechanical, electrical and ionization discharge devices and combinations thereof, detect and react to the overvoltage according to timing parameters associated with each of the E1, E2, and E3 components and shunt the overvoltage to decrease to under a predetermined allowable level. Respective shunting assemblies may include automatic self-monitoring of any faults in respective circuitry and also a challenge mode for on-demand circuit monitoring using an optical coupling switch, the optocoupler including an infrared light supplied by an LED flashlight and having a phototransistor light receiver.

Transient overvoltage suppression is provided by discharging through a Metal Oxide Varistor (MOV) and Silicon Controlled Rectifier (SCR) which are connected in series between power supply lines. The SCR has a gate that receives a trigger signal generated by a triggering circuit coupled to the power supply lines. A trigger voltage of the triggering circuit is set by a Transil avalanche diode.