A power converter including a compressor as a load includes a compensation current output (80) allowing compensation current (Ic), which compensates for leakage current (Ia), to flow. A controller (50) receives a detection signal from a rotational speed sensor (55) which senses the rotational speed of the compressor (CM). When the rotational speed has increased to a set rotational speed at which the leakage current (Ia) is lower than or equal to its limiting value (Lmax) (e.g., the limiting value specified under the Electrical Appliances and Materials Safety Act or by the IEC) in a state where the compensation current output (80) is off, the compensation current output (80) is switched from an on state to an off state. This may reduce the leakage current from the compressor with low power loss.

An apparatus for detecting noise in a power supply of a PLC analog input/output module is provided. The apparatus may include a capacitor configured to extract a noise determination target voltage from a driving voltage outputted from the power supply; a voltage conversion unit configured to convert the noise determination target voltage outputted from the capacitor and to output the converted noise determination target voltage; a comparison unit configured to compare the noise determination target voltage converted by the voltage conversion unit with a reference voltage; and a determination unit configured to determine whether the noise determination target voltage is a noise, based on a comparison result by the comparison unit.

An apparatus for detecting noise in a power supply of a PLC analog input/output module is provided. The apparatus may include a capacitor configured to extract a noise determination target voltage from a driving voltage outputted from the power supply; a voltage conversion unit configured to convert the noise determination target voltage outputted from the capacitor and to output the converted noise determination target voltage; a comparison unit configured to compare the noise determination target voltage converted by the voltage conversion unit with a reference voltage; and a determination unit configured to determine whether the noise determination target voltage is a noise, based on a comparison result by the comparison unit.

Provided is an electrostatic capacitance sensor which can remove an influence of a noise occurring from a static eliminator or a driving source and accurately perform measurement even on electrostatic capacitance detected by a thin-type detection unit which can be passed to a finger surface of a wafer transfer robot. The present invention is provided with an AC supply source which supplies an AC voltage to a detection unit, a parasitic capacitance compensation circuit, an operational amplifier, a differential amplifier, a phase detection means, and a low pass filter. An operational amplification output terminal is connected to an inversion input terminal of the differential amplifier through a first band pass filter, the AC supply source is connected to a non-inversion input terminal of the differential amplifier through a second band pass filter, an output terminal of the differential amplifier is connected to an input terminal of the phase detection means, and the phase detection means takes, as a reference signal, an AC signal output from the AC supply source.

A measurement circuit comprises an electronic circuit, multiple measurement channels, and a combining circuit. The electronic circuit includes a first terminal, a second terminal, and a non-resistive circuit element. Each of the multiple measurement channels includes a differential input connected to the electronic circuit. The differential inputs of the multiple measurement channels are connected in series and include a differential input coupled to the non-resistive circuit element. One input of a differential input of a first measurement channel of the multiple measurement channels is connected to the first terminal of the electronic circuit and one input of a differential input of a second measurement channel of the multiple measurement channels is connected to the second terminal of the electronic circuit. The combining circuit receives multiple outputs from the multiple measurement channels and produce a composite output signal.

A measurement circuit comprises an electronic circuit, multiple measurement channels, and a combining circuit. The electronic circuit includes a first terminal, a second terminal, and a non-resistive circuit element. Each of the multiple measurement channels includes a differential input connected to the electronic circuit. The differential inputs of the multiple measurement channels are connected in series and include a differential input coupled to the non-resistive circuit element. One input of a differential input of a first measurement channel of the multiple measurement channels is connected to the first terminal of the electronic circuit and one input of a differential input of a second measurement channel of the multiple measurement channels is connected to the second terminal of the electronic circuit. The combining circuit receives multiple outputs from the multiple measurement channels and produce a composite output signal.

The present invention relates to a supply voltage detection device (1), in particular for at least one load, for monitoring a rectified mains voltage of a mains voltage supply (2) and for comparing a detected mains voltage value with a predetermined reference value, wherein, if the detected mains voltage value is lower than the reference value, switching to e.g. an emergency voltage of an emergency voltage supply can be effected by means of an electronic control system (3). In addition, if a voltage limit value has been exceeded, the rectified mains voltage can be fed to an optocoupler (4) and a signal can be transmitted by said optocoupler for the duration of this excess, a duty factor that is dependent on the mains voltage value being determinable from the duration and the period of said signal.

A relay diagnosis circuit capable of diagnosing whether a relay connected to a negative electrode of a battery pack normally operates using voltage applied from a positive electrode of the battery pack.

A relay diagnosis circuit capable of diagnosing whether a relay connected to a negative electrode of a battery pack normally operates using voltage applied from a positive electrode of the battery pack.

Current sensing devices that are capable of surviving harsh ambient environment of ocean worlds, such as Jupiter and Saturn moons are disclosed. The described devices can meet 300 Krad radiation requirements and can survive at cold temperatures down to −184° C. Exemplary implementations of the constituent circuits of the devices are presented. A scheduling algorithm to perform various measurement by the disclosed current sensing devices is also described.