Abstract: The present invention relates to a signal switching method and apparatus for dividing signals to be switched into a plurality of divided signals and outputting the divided signals at a transmittal terminal, receiving the plurality of divided signals as a plurality of receiving signals at a reception terminal, and executing a switching to a signal closer to normality out of the plurality of receiving signals, wherein with respect to a through signal not to be dropped, the through signal is processed in a closed manner within one package or LSI, only a signal to be dropped is transferred to a package or LSI on a dropped side, the switching is executed, and with respect to a signal to be added, at a backboard a signal from a package or LSI on a added side is divided and sent to another route.

Abstract: There is disclosed an information recording device composed of a memory for storing an original signal from a plurality of adjacent tracks, and a computational circuit for generating an inverse number component of a crosstalk component which is considered to be mixed in during a reproduction process on the basis of storage data from the memory to provide an actual recording signal as a product of the inverse number component and the original signal to record the actual recording signal onto the recording medium, thereby canceling a crosstalk component produced at the time of reading by the inverse number component of the crosstalk component included in the actual recording signal when the actual recording signal has been read.

Abstract: This power supply is intended, more particularly, for powering a user digital terminal from a remote terminal in an integrated service digital telephone network. It comprises a main D.C. electricity power source (10) provided with a protection device (11) causing its output to go to a high impedance state in the absence of a voltage across its terminals, and an auxiliary D.C. electricity power source (20) connected in parallel and in opposition with the main source (10) and provided with a current limiting device (20) which is normally tripped by the additional current which the main source (10) attempts to impose thereon.