An arrangement having two redundant modules that monitor one another and that each contain a current or voltage source, which is connected to a first line terminal via a first controllable switch and a first current sensor, wherein each module also has a second line terminal and a ground terminal, between which lies a second current sensor in series with a second controllable switch, where each module, when in the functioning state, closes the controllable switches contained therein, and contains a monitoring device connected to the two current sensors of the modules, the monitoring device generating a monitoring signal identifying the corresponding other module as functioning if at least one of the two current sensors detects a current flow.

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.

A battery system includes a battery module having a plurality of assembled batteries. Battery monitoring circuits are provided to correspond to each of the assembled batteries of the battery module. A control circuit controls operation of the battery monitoring circuits. A first signal transmission path transmits signals that are input and output between the battery monitoring circuits and the control circuit. A first isolation element is connected to the control circuit, and a second isolation element is connected to the battery monitoring circuit. The first signal transmission path is isolated from the control circuit by the second isolation element. The electrical potential of the first signal transmission path is a floating potential in relation to the electrical potentials of the control circuit and battery monitoring circuits.

A battery system includes a battery module having a plurality of assembled batteries. Battery monitoring circuits are provided to correspond to each of the assembled batteries of the battery module. A control circuit controls operation of the battery monitoring circuits. A first signal transmission path transmits signals that are input and output between the battery monitoring circuits and the control circuit. A first isolation element is connected to the control circuit, and a second isolation element is connected to the battery monitoring circuit. The first signal transmission path is isolated from the control circuit by the second isolation element. The electrical potential of the first signal transmission path is a floating potential in relation to the electrical potentials of the control circuit and battery monitoring circuits.

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.

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.

A structure and method of operating an optical step-up transformer are described. The optical step-up transformer has at least one photodiode and at least one photoreceiver. The photoreceiver receives light emitted from the photodiode and generates a voltage proportional to the number of series-connected photoreceivers. The photodiode and photoreceiver may be electrically isolated or may share a common anode or cathode. The voltage applied to the photodiode may be a DC or PWM signal.

A structure and method of operating an optical step-up transformer are described. The optical step-up transformer has at least one photodiode and at least one photoreceiver. The photoreceiver receives light emitted from the photodiode and generates a voltage proportional to the number of series-connected photoreceivers. The photodiode and photoreceiver may be electrically isolated or may share a common anode or cathode. The voltage applied to the photodiode may be a DC or PWM signal.