Abstract: The invention relates to a safe electronic device which has multichannel logic circuitry, a single channel input device, an output device, and a storage device. Data items, each of which is associated with an input value, are stored in the storage device. The multichannel logic circuitry is comprised of a first control unit and a second control unit. The first control unit reads in an input value which has been input, and transmits the input value to the second control unit which actuates the output device for outputting of optical and/or acoustic information, in response to the input value which has been input. If the optical and/or acoustic information corresponds to the input value, the selected data item is released for further use.

Abstract: The invention relates to a safe electronic device which has multichannel logic circuitry, a single channel input device, an output device, and a storage device. Data items, each of which is associated with an input value, are stored in the storage device. The multichannel logic circuitry is comprised of a first control unit and a second control unit. The first control unit reads in an input value which has been input, and transmits the input value to the second control unit which actuates the output device for outputting of optical and/or acoustic information, in response to the input value which has been input. If the optical and/or acoustic information corresponds to the input value, the selected data item is released for further use.

Abstract: A method and apparatus employs Hall probes for contactless, longitudinal and transversal homogeneity examination of a critical current density j.sub.c in a superconductor tape that is cooled to below a transition temperature T.sub.c. The cooled superconductor tape is pulled through an external, locally limited magnetic field that has a constant gradient and a fixed magnetic field axis. The magnetic field generated by a screening current induced in a region of the superconductor tape penetrated by the external magnetic field is scanned using a first Hall probe at a distance of a few tenths of millimeters to the superconductor tape. The external magnetic field outside of a field range of the induced persistent currents is measured with a second Hall probe. A compensated difference between the first and second Hall probe signals is used as a qualitative measure for a critical current density j.sub.