Abstract: An electrical device, in particular a car radio, allows more user-friendly checking of access authorization is described. The electrical device includes a disc drive for a storage medium, a read device being provided for reading data stored on the storage medium placed in the disc drive. Device-specific data is stored in a memory assigned to the electrical device. Data read from the storage medium is compared with the device-specific data. The electrical device is only rendered operational if the data that has been read matches the device-specific data.

Abstract: A radio receiver having a circuit arrangement for checking the quality of reception at an alternative frequency to a received transmit frequency. The radio receiver has two tuners for converting the received signals to two different intermediate frequencies and a switch, which is preferably switched by a microprocessor, for optionally forwarding signals from signal processing branches that are each connected to one of the tuners. This reduces the cost of implementing the second receiver, at the same time reducing the barely noticeable impairment of the set program when checking the quality of reception at the alternate frequency. The latter is achieved by positioning the switch upstream from an analog-digital converter, operating at a sampling frequency, of an intermediate frequency stage. The different intermediate frequencies are selected so that they both meet the following condition: f0=(n+R)fa where n is a natural number, and 0≦R≦1 applies.

Abstract: The present invention includes a navigation process and a navigation system for a vehicle, especially a motor vehicle, a ship or aircraft, for navigating the vehicle from a starting position to a destination, in which a predetermined destination and, if necessary, a starting position are input into the navigation system. In this navigating method one or more predetermined numbers designating the predetermined destination and, if necessary, the starting position are input to the navigation system; then the one or more numbers are correlated with one or more position addresses from a position address list provided in a memory device and are read out from the memory device; and the one or more position addresses output from the memory device are assigned as the destination and, if necessary, the starting position. Preferably the numbers input to the memory device are telephone numbers of telephones located at the different destinations and the memory device includes a CD-ROM.

Abstract: A transistor with its collector connected to a point near the screen grid in the resistor network which feeds voltage from the high voltage rectifier of a picture tube to the screen grid electrode and its emitter connected to ground has two control circuits connected to its base electrode. The first control circuit (56) is a threshold circuit responsive to a voltage proportional to the beam current of the picture tube for making the control transistor provide a short circuit between the picture tube screen grid and ground, and thereby preventing a burnout when there is persistent excessive beam current. The second control circuit (58) acts on the base electrode of the control transistor to set the screen grid voltage of the picture tube at a desired value in normal operation, for example in accordance with the pulse width of a train of pulses of settable pulse width.