Siemens Aktiengesellschaft

Friwo Geraetebau Gmbh

Varta Aktiengesellschaft

Rainer Peters

Michael Bothe

Rudolf Hauptmann

Klaus Goebel

Guenter Beyer

Juergen Heydecke

Ingmar Knop

Armin Wegener

Klaus-Dieter Skwirblies

A device for protecting the electronic circuitry of electrical appliances against damage from unacceptably high voltages. An element is interposed in the power supply paths which limits the application of an externally supplied excessive voltage to a predetermined time interval and which completely interrupts the current flow when the excessive voltage and current causes a heat build-up. This is accomplished by interposing pairs of spaced-apart solder surfaces at at least one point along the current paths to the electronic circuitry. One solder surface of each pair is connected to the power supply and the other to the power consumer. An element is soldered to the respective solder surfaces of the pairs and electrically closes the current path. A mechanically prestressed spring engages the element and reliably separates it from the solder surfaces when the solder melts due to excessive heating.

Apparatus for protecting electronic circuitry

A three-dimensional air space surveillance radar in which the radar receiver is connected to a target tracking means which stores target data and does extrapolation of target data for target trace formations, including a panoramic antenna which illuminates the entire elevation range to be covered and has a reception lobe at the elevation level which can be electronically or mechanically controlled such that a line air space scanning occurs during the course of normally sequence scanning programs. The line-shaped beam of the antenna is briefly interrupted in the invention from the normal reception lobe elevation angle when the tracker determines that a target echo is expected from a different elevation angle than that being scanned. During such scanning interrupt, the reception lobe is switched to the expected elevation angle of the target and in the invention, the data acquisition rate for the tracker is increased relative to known prior art three-dimensional surveillance radars which function on a strictly time sequential manner. The precision of the invention is retained and the invention is utilized in a tracker-equipped three-dimentional air space surveillance radar of high trace quality such as used, for example, in air defense radar.

Three-dimensional air space surveillance radar

A fixed target echo rejection circuit in a pulse Doppler radar device which uses recursion filters and which have a return loop with the feedback signal passing through a weighting multiplier. The weighting function of the recursion signal occurs when a change of the pulse repetition frequency (PRF) occurs by switching and changing the weighting factors. So as to reduce spurious signals which would occur during switching, the weighting factor switching is delayed and carried when the recursion signal passes through a zero value so as to substantially reduce the spurious signals.

Pulse Doppler radar with fixed target echo rejection circuit formed of

Growing community of inventors

Unterhaching, Germany

Rainer Peters