Abstract: In automatic diagnosis equipment for automobiles, it is essential for proper results that the datacarrier which carries the coded vehicle specifications corresponds with the vehicle to be tested. The present invention provides a system for checking correspondence between the datacarrier and the car to be tested which comprises a code-key in which the car characterizing code is recorded, said code corresponding with a code recorded on the datacarrier, and means for reading out the code on the code-key and the code on the datacarrier, for comparing them and for signaling and/or blocking the test program in the event of absence of agreement.

Abstract: A system for demodulating angle modulated waves comprises a phase locked loop including a phase comparator and a voltage controlled oscillator. An attenuation means is inserted into the phase locked loop. This attenuation means does not affect the DC component of an input angle modulated wave, but does cause an attenuation with respect to an AC component, to cause a decrease in the loop gain. The phase locked loop has a DC lock range exhibiting a relatively wide lock range width even when the input level is relatively low and an AC lock range produced by the attenuation circuit and exhibiting a relatively narrow lock range width when the input level is relatively low. The attenuation means detects an abnormality in the angle modulated wave, the harmonics component of the direct wave, and the like. A variable attenuation circuit controlled by the output of the detecting means is varied in its attenuation quantity.

Abstract: Overlay patterns of discrete circuit elements for field-accessed, magnetic bubble propagation are driven by repetitive sequences of pulsed magnetic fields directed along axes which are parallel to consecutive overlay elements or segments with different orientations. A chevron circuit is driven by a series of reversing pairs of pulsed fields aligned alternately with the legs of the chevron elements. Two opposite parallel chevron circuits are driven in the same direction by the same sequence of pulsed fields. A broken element circuit, resembling a chevron circuit with the vertices removed, is driven in a similar manner.

Abstract: An electronic security card and system for authenticating ownership of the card is disclosed. The system comprises a security card and a terminal. The security card includes logic circuitry which is responsive to a plurality of input signals and which is operative to provide an output signal if the input signals are in a preselected sequence and to develop a feedback control signal which is applied to, and deactivates, the logic circuitry if the input signals are not in the preselected sequence. The terminal comprises a source of input signals, a switching network for selectively interconnecting the source to the logic circuitry so as to apply a sequence of input signals to the logic circuitry when the security card is received by the terminal, and an indicator responsive to the output signal and operative to provide an indication of the authenticity of the user of the security card.

Abstract: A completely enclosed housing of a magnetically permeable material contains a pair of magnetic discs. A magnetic bubble chip mounted in a gap between the magnetic discs is thereby subjected to a d.c. magnetic bias field provided by the discs but is also shielded from the effects of external magnetic fields. The device may be precisely magnetized by applying in succession two external magnetic fields of suitable magnitude, in opposite directions.