An arrangement has a coaxial resistor. The coaxial resistor is to be placed on an electrically conductive housing, and sensor lines of the coaxial resistor are to be guided through an interior of the coaxial resistor into the interior of the electrically conductive housing and to be connected to an electrical interface in the electrically conductive housing.

Within electrical test equipment systems comparator bridges are employed to provide the required dynamic range, accuracy, and flexibility. However, whilst bridge based measurement configurations remove many of the issues associated with making measurements at accuracies of sub-parts, a part, or few parts per million they still require, in many instances, that a null point be determined where the bridge is balanced. However, this becomes increasingly difficult within electrically noisy environments, with modern digital multimeters, and where the desired measurement point within the electrical system is physically difficult to access particularly when improved accuracy in calibration, standards, and measurements on circuits and components means measurement systems must operate at 50 parts per billion (ppb) and below. In order to address this, a null detector design is provided supporting operation within such electrically noisy environments with physical separation of the null detector measurement circuit from the electrical test equipment.

Within electrical test equipment systems comparator bridges are employed to provide the required dynamic range, accuracy, and flexibility. However, whilst bridge based measurement configurations remove many of the issues associated with making measurements at accuracies of sub-parts, a part, or few parts per million they still require, in many instances, that a null point be determined where the bridge is balanced. However, this becomes increasingly difficult within electrically noisy environments, with modern digital multimeters, and where the desired measurement point within the electrical system is physically difficult to access particularly when improved accuracy in calibration, standards, and measurements on circuits and components means measurement systems must operate at 50 parts per billion (ppb) and below. In order to address this, a null detector design is provided supporting operation within such electrically noisy environments with physical separation of the null detector measurement circuit from the electrical test equipment.

A fiber optic sensor for measuring voltage in direct current and alternating current systems is disclosed. The sensor may include an optical fiber probe containing transmitting and receiving fibers, fixed conductor elements, and a dynamic conductor element with a reflective surface or material. The reflector may be attached to a dynamic conductor. The two fixed conductors may be placed parallel to one another and coupled to a static voltage source. The dynamic conductor may bisect the fixed conductors and be coupled to a voltage source. The dynamic conductor may be spaced apart from the ends of the fibers in the fiber probe, and positioned so that light transmitted through the transmitting fiber is reflected by that surface into a receiving fiber. A light sensing means may be coupled to the receiving fiber, so light from a light reflected by the reflector body back into the receiving fibers is detected.

A fiber optic sensor for measuring voltage in direct current and alternating current systems is disclosed. The sensor may include an optical fiber probe containing transmitting and receiving fibers, fixed conductor elements, and a dynamic conductor element with a reflective surface or material. The reflector may be attached to a dynamic conductor. The two fixed conductors may be placed parallel to one another and coupled to a static voltage source. The dynamic conductor may bisect the fixed conductors and be coupled to a voltage source. The dynamic conductor may be spaced apart from the ends of the fibers in the fiber probe, and positioned so that light transmitted through the transmitting fiber is reflected by that surface into a receiving fiber. A light sensing means may be coupled to the receiving fiber, so light from a light reflected by the reflector body back into the receiving fibers is detected.

Provided is a technology for suppressing variations in the waveform of a light emission pulse caused by various factors in a light-emitting device. A light-emitting device is provided with: a light source 101 in which relaxation oscillation occurs immediately after energization; a light source drive circuit 104 which includes a differentiation circuit 102 having a resistor and a capacitor connected in parallel, and in which a switching element 103 for voltage application is connected in series with the differentiation circuit; a power supply circuit 105; a light-reception element 107 which detects pulsed light emitted from the light source 101; and a voltage control unit 109 which controls an output voltage from the power supply circuit 105 in correspondence with the waveform of the detected pulsed light.

Provided is a technology for suppressing variations in the waveform of a light emission pulse caused by various factors in a light-emitting device. A light-emitting device is provided with: a light source 101 in which relaxation oscillation occurs immediately after energization; a light source drive circuit 104 which includes a differentiation circuit 102 having a resistor and a capacitor connected in parallel, and in which a switching element 103 for voltage application is connected in series with the differentiation circuit; a power supply circuit 105; a light-reception element 107 which detects pulsed light emitted from the light source 101; and a voltage control unit 109 which controls an output voltage from the power supply circuit 105 in correspondence with the waveform of the detected pulsed light.

A system and method for monitoring, testing or configuring electrical devices includes an input amplifier having an input connected to a device load line to generate an output linearly proportional to a voltage on the load line. An output of the input amplifier is connected to a photodiode in an optical path with a phototransistor. The phototransistor generates an output proportional to light generated by the photodiode, and this output is amplified and passed to an analog-to-digital converter. The converter generates a digital voltage level corresponding to the amplified output of the phototransistor. Digital temperature information is used to further enhance linearity of a generated digital voltage level. Multiple quantum well photodiodes further improve measurement linearity.

An apparatus includes a zero steady state error regulator with a first input terminal operatively coupled to an isolated power supply primary voltage. A PWM (pulse width modulation) generator is operative to generate two identical PWM signals, each having a duty ratio proportional to the primary voltage. The PWM generator has an input terminal operatively coupled to the zero steady state error regulator output terminal, and has a first output terminal operatively coupled to a second input terminal of the zero steady state error regulator to a provide a feedback signal. An optical coupler has an input terminal operatively coupled to a second output terminal of the PWM generator. A scaling circuit has an input terminal operatively coupled to the optical coupler output terminal and has a scaling circuit output terminal to provide a scaled PWM output signal having a duty ratio that is linearly proportional to the primary voltage.

An apparatus includes a zero steady state error regulator with a first input terminal operatively coupled to an isolated power supply primary voltage. A PWM (pulse width modulation) generator is operative to generate two identical PWM signals, each having a duty ratio proportional to the primary voltage. The PWM generator has an input terminal operatively coupled to the zero steady state error regulator output terminal, and has a first output terminal operatively coupled to a second input terminal of the zero steady state error regulator to a provide a feedback signal. An optical coupler has an input terminal operatively coupled to a second output terminal of the PWM generator. A scaling circuit has an input terminal operatively coupled to the optical coupler output terminal and has a scaling circuit output terminal to provide a scaled PWM output signal having a duty ratio that is linearly proportional to the primary voltage.