Disclosed herein are optical stacks that are stable to light exposure by incorporating one or more UV-blocking layers.

A resistance measuring device includes an amplifying unit including an amplifier, a first and a second current supply unit, a voltage detection unit, and a controller. The controller controls the voltage detection unit to detect a first output voltage of an output terminal of the amplifier in a state where the current of the first current source flows in a forward direction to a measurement target resistor by controlling the first current supply unit, controls the voltage detection unit to detect a second output voltage of the output terminal of the amplifier in a state where the current of the second current source flows in a reverse direction to the measurement target resistor by controlling the second current supply unit, and calculates a resistance value of the measurement target resistor based on the detected first output voltage and the detected second output voltage.

A resistance measuring device includes an amplifying unit including an amplifier, a first and a second current supply unit, a voltage detection unit, and a controller. The controller controls the voltage detection unit to detect a first output voltage of an output terminal of the amplifier in a state where the current of the first current source flows in a forward direction to a measurement target resistor by controlling the first current supply unit, controls the voltage detection unit to detect a second output voltage of the output terminal of the amplifier in a state where the current of the second current source flows in a reverse direction to the measurement target resistor by controlling the second current supply unit, and calculates a resistance value of the measurement target resistor based on the detected first output voltage and the detected second output voltage.

In described examples, one or more devices include: apparatus including a lens element and a transducer to vibrate the lens element at an operating frequency when operating in an activated state; and controller circuitry. The controller circuitry is arranged to measure an impedance of the apparatus, to determine an estimated temperature of the apparatus in response to the measured impedance, to compare the estimated temperature against a temperature threshold for delineating an operating temperature range of the apparatus, and to toggle an activation state of the transducer in response to comparing the estimated temperature against the temperature threshold.

In some implementations, a measurement circuit may drive, using a first transistor, a first node of a haptic load. The measurement circuit may trigger a first comparator when a voltage driving the haptic load satisfies a first condition. The first comparator may have a first node connected, in parallel, to a drain of a second transistor and may have a second node connected to the first node of the haptic load. Additionally, the second transistor may have a gate connected to a gate of the first transistor and may have the drain connected to a first reference current.

Circuits for measuring a leakage current of one or more capacitors coupled to a power supply line that powers an apparatus, such as a storage device, are disclosed. In one embodiment, the circuit includes first and second resistors between the power supply line, and first and second respective switches to ground. A controller may charge the voltage line to a first voltage. Thereafter, the controller discharges the first voltage to a second voltage via the first resistor during a first identified time. After recharging the voltage line, the controller then discharge the first voltage to the second voltage via at least the second resistor during a second identified time. The controller determines the parasitic resistance using the first and second identified times, and then the leakage current from the parasitic resistance. Removing the leakage current factor from subsequent measurements can greatly improve testing accuracy and can avoid false positives in the testing process that would otherwise require removal of drives or other systems that are working properly.

A method and system for resistivity imaging. A method may comprise disposing a downhole tool into a borehole, applying a voltage difference between the array of injector electrodes, constructing a first set of formation images for each of the plurality of frequencies, applying a mud effect removal algorithm to produce a second set of formation images for each of the plurality of frequencies, applying a dielectric correction algorithm to each of the plurality of frequencies to produce a third set of formation images for each of the plurality of frequencies, and combining the first set of formation images, the second set of formation images, and the third set of formation images to obtain a blended image. A system for resistivity imaging may comprise a downhole tool. The downhole tool may comprises a pad, an array of injector electrodes, and one or more return electrodes.

A method and system for resistivity imaging. A method may comprise disposing a downhole tool into a borehole, applying a voltage difference between the array of injector electrodes, constructing a first set of formation images for each of the plurality of frequencies, applying a mud effect removal algorithm to produce a second set of formation images for each of the plurality of frequencies, applying a dielectric correction algorithm to each of the plurality of frequencies to produce a third set of formation images for each of the plurality of frequencies, and combining the first set of formation images, the second set of formation images, and the third set of formation images to obtain a blended image. A system for resistivity imaging may comprise a downhole tool. The downhole tool may comprises a pad, an array of injector electrodes, and one or more return electrodes.

Disclosed is an insulation detection circuit for voltage balance, including a bus battery, a bus positive voltage dividing circuit, a bus negative voltage dividing circuit, a differential amplification circuit and a micro controller unit (MCU) module. The bus battery is respectively connected with the bus positive voltage dividing circuit and the bus negative voltage dividing circuit, the bus positive voltage dividing circuit and the bus negative voltage dividing circuit is respectively connected with the differential amplification circuit, and the differential amplification circuit being connected with the MCU module; the bus battery is configured for supplying power to each module; the bus positive voltage dividing circuit is configured for converting a positive voltage of the bus from high voltage to detectable low voltage; the bus negative voltage dividing circuit is configured for converting a negative voltage the bus from high voltage to detectable low voltage.

An apparatus and system are provided for detecting leaks in cooling tubing using sensor cabling. In the leak detection system, a leak detection cable is routed along the full length of the cooling tube. The leak detection cable and the cooling tubing are encased within a shrunken tube, which leaves such a small gap between the cooling tubing and the heat-shrunk tube that leakage is distributed within the gap about the outside of the cooling tubing by capillary action. The relative position of the detection cable above or below the cooling tubing is then irrelevant, since the capillary action may overcome the effect of gravity and distribute leakage from the bottom of the tubing to a detection cable at the top of the tubing.