A pulse oximetry system for reducing the risk of electric shock to a medical patient can include physiological sensors, at least one of which has a light emitter that can impinge light on body tissue of a living patient and a detector responsive to the light after attenuation by the body tissue. The detector can generate a signal indicative of a physiological characteristic of the living patient. The pulse oximetry system may also include a splitter cable that can connect the physiological sensors to a physiological monitor. The splitter cable may have a plurality of cable sections each including one or more electrical conductors that can interface with one of the physiological sensors. One or more decoupling circuits may be disposed in the splitter cable, which can be in communication with selected ones of the electrical conductors. The one or more decoupling circuits can electrically decouple the physiological sensors.

A digital isolator can include: an encoding circuit configured to receive an input digital signal, and to generate an encoded signal according to the input digital signal; an isolation element having a primary winding, a first secondary winding, and a second secondary winding; a differential circuit configured to receive first and second differential signals, and to generate a difference signal according to the first and second differential signals; and a decoding circuit coupled with the differential circuit, and being configured to receive the difference signal, and to generate a target digital signal after decoding.

A system uses optical signals to monitor real world inputs and convert them to electrical signals for conventional indication and control systems. Optical signals see use where electrical signals cannot and improve reliability of existing control systems. Optical loops extend to peripheral devices which process the light into discrete or analog light signals. A receiving circuit interprets that signal and converts it to a useable electrical signal of discrete or analog form. The system operates within a range of light wavelength from at least as low as 399 nm up to at least as high as 1801 nm. The system replaces electrical conductors for input cards of Programmable Logic Controller systems. The optical sensing devices withstand electrical surges and immersion into water, do not generate electrical noise, allow for maintenance without shock hazard, and lack susceptibility to electrical or magnetic phenomenon.

An optical isolator system comprises an electrical-to-optical converter apparatus for receiving an input electrical signal from a system of an aircraft and converting the input electrical signal into an optical signal which is representative of the input electrical signal. The optical isolator system further comprises an optical-to-electrical converter apparatus for receiving the optical signal from the electrical-to-optical converter apparatus, for converting the received optical signal into an output electrical signal which is representative of the received optical signal, and for transmitting the output electrical signal to a portable server for the wireless distribution of content such as visual content, web content, video content, audio content, games, services, information and/or advertising content to clients in the aircraft. Associated methods are also described.

An EMC test bench, includes an item of equipment under test to be loaded on board an aircraft, the item of equipment being subjected to EMC tests and delivering ARINC electrical interfaces as inputs and as output; an electrical interfaces device representative of an item of anti-lightning equipment and including an ARINC signals acquisition and/or generation card connected to the ARINC inputs and outputs of the item of equipment under test; a command and control rack for analyzing control signals originating from the electrical interfaces device including the ARINC signals acquisition and/or generation card, and a signals conversion system for protecting the command and control rack connected between the command and control rack and the electrical interfaces device.

A quasi-optical coupling system launches and extracts surface wave communication transmissions from a wire. At millimeter-wave frequencies, where the wavelength is small compared to the macroscopic size of the equipment, the millimeter-wave transmissions can be transported from one place to another and diverted via lenses and reflectors, much like visible light. Transmitters and receivers can be positioned near telephone and power lines and reflectors placed on or near the cables can reflect transmissions onto or off of the cables. The lenses on the transmitters are focused, and the reflectors positioned such that the reflected transmissions are guided waves on the surface of the cables. The reflectors can be polarization sensitive, where one or more of a set of guided wave modes can be reflected off the wire based on the polarization of the guided wave modes and polarization and orientation of the reflector.

A technique related to a semiconductor chip is provided. An optical gain chip is attached to a semiconductor substrate. An integrated photonic circuit is on the semiconductor substrate, and the optical gain chip is optically coupled to the integrated photonic circuit thereby forming a laser cavity. The integrated photonic circuit includes an active intra-cavity thermo-optic optical phase tuner element, an intra-cavity optical band-pass filter, and an output coupler band-reflect optical grating filter with passive phase compensation. The active intra-cavity thermo-optic optical phase tuner element, the intra-cavity optical band-pass filter, and the output coupler band-reflect optical grating filter with passive phase compensation are optically coupled together.

An electronic circuit includes an isolation amplifier, having a first input terminal receiving an AC-signal and including a linear opto-isolator. The opto-isolator has a first output terminal that provides a unipolar signal having an AC-component proportional to the input signal. The circuit includes a transimpedance receiver with first and second operational amplifiers. The first amplifier has a second output terminal and first and second differential input terminals, with the first differential input terminal receiving and amplifying the unipolar output signal from the first output terminal providing an output signal from the circuit at the second output terminal. The second amplifier is configured as an integrator, having a third output terminal coupled to the second differential input terminal and having third and fourth differential input terminals, with the third differential input terminal receiving the output signal from the second output terminal and the fourth differential input terminal connected to ground.

An outdoor unit and an indoor unit communicate with each other. The outdoor unit includes a communication circuit that outputs a pulse signal to be transmitted to the indoor unit. The indoor unit includes a communication circuit that receives the pulse signal transmitted by the outdoor unit. An air conditioner 100 includes at least one photocoupler to transfer to the communication circuit the pulse signal output by the communication circuit. The communication circuit transmits a pulse signal with a first polarity and a pulse width corrected to be shorter by a predefined correction time than a predefined reference pulse width of the pulse signal.

A signal isolation system includes an external device; and a signal isolation circuit, coupled to the external device, including a control circuit, configured to operate the signal isolation circuit in an input mode or an output mode according to a status of the external device; a digital input/output circuit, configured to input/output signal based on the input mode or the output mode determined by the control circuit; and an input/output port, coupled to the digital input/output circuit, configured to be an input port or an output port according to the input mode or the output mode determined by the control circuit.