Abstract: A direct-current stabilized power supply device for stepping down an input voltage from a solar cell, including: a first constant voltage power supply circuit connected to the solar cell and including a constant current limiter circuit; a switch circuit; a switching-type second constant voltage power supply circuit connected to the switch circuit; and a voltage detection circuit that detects the output voltage of the first constant voltage power supply circuit. When the detected output of the first power supply circuit is equal to or higher than a first determination voltage, the switch circuit is closed, and power is supplied to the load from the second power supply circuit, and when the detected voltage is equal to or lower than a second, lower, determination voltage the switch circuit is opened, and the power supplied from the second power supply circuit is stopped.

Abstract: The present invention provides an apparatus for easily detecting an abnormal status of power generation of a solar cell panel in a solar cell power generation system having the power generation of 1 MW or higher. The present invention provides an abnormality detecting apparatus for a solar cell power generation system including a plurality of solar cell strings each having a plurality of solar cell modules connected to each other in series and a backflow preventing diode connected to a power output terminal of each of the solar cell strings, characterized in that the abnormality detecting apparatus further includes measuring means for measuring a current flowing in the backflow preventing diode; and that the measuring means is supplied with electric power from both terminals of the backflow preventing diode.

Abstract: A failure detecting method for a solar power generation system having plural solar cell strings in each of which plural solar cell modules are connected to each other in series. Specifically, by comparing the current value of each of the solar cell modules or strings with the average current value per one module or string, calculated from the total current value of the entire solar cell modules or strings, one or more failure candidates can be detected with high precision.

Abstract: A direct-current stabilized power supply device that drops a voltage from a power supply of a solar cell in which output power is unstable, and supplies a stable voltage necessary for measurement equipment and the like.

Abstract: The present invention discloses a failure detecting method for a solar power generation system having plural solar cell strings in each of which plural solar cell modules are connected to each other in series.

Abstract: The present invention provides an apparatus for easily detecting an abnormal status of power generation of a solar cell panel in a solar cell power generation system having the power generation of 1 MW or higher. The present invention provides an abnormality detecting apparatus for a solar cell power generation system including a plurality of solar cell strings each having a plurality of solar cell modules connected to each other in series and a backflow preventing diode connected to a power output terminal of each of the solar cell strings, characterized in that the abnormality detecting apparatus further includes measuring means for measuring a current flowing in the backflow preventing diode; and that the measuring means is supplied with electric power from both terminals of the backflow preventing diode.

Abstract: By the extraction of the noise component from the FM demodulated output and the detection thereof, the output proportional to the noise power is obtained, and it is indicated as the CN ratio of the received signal. This quality indication of the received signal makes the antenna pointing angle adjustment easier than before, and also realizes the picture quality indication for a satellite broadcasting receiver.

Abstract: A satellite TV receiver for receiving a satellite broadcasting, wherein neighboring televison signals are vertical and horizontal polarized waves, and wherein a polarizer for the satellite receiver controls an antenna so that the polarization plane of the antenna is adapted to the polarization plane of television signal to be received. The receiver further includes a narrow band-pass filter for rejecting terrestrial interference so that the desired polarization plane can be more easily determined.

Abstract: In apparatus for receiving a television signal which is made by a frequency-modulation by a video signal, the improvement is that a band-pass filter provided in the receiver for selectively taking out selected television signal is designed in a manner to have a center frequency shifted from a frequency corresponding to the center level of the video signal to the side of another frequency corresponding to white-signal level, so that noises of the picture in small signal receiving is decreased.