A light emitting device capable of performing optimum temperature control of an LED in accordance with each of a plurality of photographing assist uses and sufficiently exhibiting performance of each of uses while ensuring reliability of the LED. The light emitting device includes an LED configured to assist photographing of an image capturing apparatus and a temperature sensor. The light emitting device operates at least in one of a first light emission mode in which a light emission time in one lighting operation of the LED is a first time period and a second light emission mode in which the light emission time is a second time period shorter than the first time period. Different light emission controls are performed on the LED between the first light emission mode and the second light emission mode based on temperature information detected by the temperature sensor.

A voltage detection unit includes a voltage detection terminal, an electric wire, a housing including a terminal accommodating concave and an electric wire accommodating concave, and a cover. The cover includes an extension piece extending in a first direction in which the cover is attached to the housing. The housing includes an accommodating hole to accommodate the extension piece. The electric wire accommodating concave includes an inclined surface and a guide surface. The inclined surface is inclined with respect to the first direction such that a first thereof end is provided closer to the accommodating hole than a second end thereof in a second direction perpendicular to the first direction and being parallel to the housing. The guide surface is continuous with the inclined surface and continuous with an inner wall surface of the accommodating hole.

A method for estimating resistances of a circuit having a plurality of resistances comprising a first resistance and a second resistance may include applying a first bias voltage across the circuit and measuring a first voltage at a common node between the first resistance and the second resistance in order to determine a mathematical relationship between the first resistance and the second resistance, applying a second bias voltage across the circuit and a third resistance in parallel with the circuit and measuring a second voltage at the common node between the first resistance and the second resistance in order to determine a mathematical relationship between the third resistance and at least one of the first resistance and the second resistance, and based on at least the measurement of the first voltage and the measurement of the second voltage, determining the first resistance and the second resistance as a function of the third resistance.

A sensor assembly includes a connecting bar extending along a longitudinal axis and a tubular body extending along the longitudinal axis and at least partially surrounding the connecting bar such that the tubular body is radially spaced from the connecting bar. The tubular body includes a support member made of insulating material. The tubular body also includes a first section with an electric field sensor comprising a first layer of electrically conductive material on an inner surface of the support member to detect an electric field produced by the connecting bar. The first section also includes a first electric screen comprising a second layer of electrically conductive material on an outer surface of the support member to shield the electric field sensor from outside electrical interference. A second section disposed adjacent the first section includes a second electric screen. A dielectric material at least partially encloses the tubular body.

A front-end device for monitoring operation of an associated electric power device with semiconductor power switches generating a power output, e.g. a three-phase power output. The front-end device has input terminals arranged for connection to the electric phase(s) of the power output of the associated electric power device, and an electric circuit connected to the input terminals and connected to at set of output terminals. The electric circuit has a passive interconnection comprising electric semiconductor switches and diodes. The electric circuit serves to electrically block any high voltage component from the input terminals from reaching the output terminals, while allowing an on-state voltage of at least one semiconductor power switch in the associated electric power device to pass to the at least two output terminals. The front-end allows low voltage equipment to be connected to its output terminals for determining an on-state voltage of switches of the electric power device. Especially, embodiments with self-powered reference voltage circuits provided by zener diodes allow compact low cost versions for use in e.g. portable test equipment or as part of permanently installed health condition monitoring of power devices. The front-end device can be used as a simple and low cost solution for non-invasive health condition monitoring of power devices, e.g. power converters in such as power electric generation system or electric vehicles. Such monitoring allows predictive maintenance to be performed to avoid any faults in the power device that may cause permanent damages.

An isolated voltage probe includes: a conductor including a positive lead, a negative lead, and a resistance via which the positive lead and the negative lead are connected to each other; a magnetic sensor for measuring a magnetic field in a non-contact manner, the magnetic field being generated by a current flowing through the conductor; and a coaxial cable for transmitting a signal that is based on an output supplied from the magnetic sensor.

A circuit chip is connected to a sensor chip in a sub-unit via a communication terminal, and includes an output wave formation circuit that performs communication by controlling a voltage of a power supply supplied from an electronic control unit (ECU) to raise a voltage level of an output signal. When the voltage of the power supply monitored by a voltage monitor rises above a threshold value, a control circuit lowers a voltage of a signal from the output wave formation circuit, thereby preventing an excessive rise of the power supply voltage used in a signal communication.

A failure detection apparatus includes: a first switch configured to be connected to a positive electrode of a battery; a second switch configured to be connected to a negative electrode of the battery; detection resistances that are connected in series between the first switch and the second switch; and a measurement circuit that measures a voltage of the detection resistances, wherein (i) both the first switch and the second switch are turned on to form a failure-detection series-connected circuit consisting of the battery and the detection resistances, and (ii) a failure detection mode is provided to detect a failure based on the voltage measured by the measurement circuit.

A diode voltage measurement system can include a plurality of diodes connected in series along a single line. The plurality of diodes can include N diodes. The system can include a plurality of capacitors for at least N−1 of the diodes. Each capacitor can be connected in parallel to the single line with a respective diode to form a respective diode-capacitor (DC) pair. Each DC pair can be configured such that each DC pair reaches a steady state voltage at a different time. The system can include a current supply connected to the single line to supply a current to the line. The system can include a control module configured to sense a total voltage across the single line and to successively determine voltage of each diode from the total voltage based on the current, a known total steady state voltage, and known time-to-steady-state-voltages of each DC pair and/or diode.

A power module device, comprising a main switch and a detection unit. The main switch is electrically connected between a first detection node and a second detection node. The first detection node and the second detection node are electrically connected between a plurality of power supply nodes, and are substantially two ends of the main switch. When the main switch is turned on, the main switch is configured to transmit a current flowing through the plurality of power supply nodes. The detection unit is electrically connected to the first detection node and the second detection node, and configured to detect a voltage across the two ends of the main switch to generate a detection voltage.