Abstract: A piezoelectric sensitive element has elements for collecting charges appearing between the sides of the piezoelectric element. These elements include a flexible insulating strip having one the same face two distinct conductive layers each of which has an annular layer for contact with the piezoelectric sensitive element and connected by a connecting layer to a terminal layer. Application is to the detection of pinging in internal combustion engines.

Abstract: Precision high-voltage resistor comprising a plane substrate of insulating material (1) on which there has been deposited by silk-screening at least one resistive film (3) of approximately rectangular, square or similar shape and a conductive film in the form of two parallel strips (2a, 2b) extending along two opposite edges of the resistive film and constituting terminals electrically connected to one another by said resistive film, the resistive film comprising rectilinear cuts (5a to 5f) made in its thickness, down to the insulating substrate, parallel to said opposite edges from a third edge (6) of the resistive film, characterized in that the rectilinear cuts (5a to 5f) are evenly spaced along the third edge (6) and have lengths that are larger the closer they are to the center of the third edge (6), the ends opposite the third edge (6) of the rectilinear cuts defining from the intersections (8a, 8b) of the third edge (6) with the terminals (2a, 2 b) a contour (7; 9) exhibiting an apex in its center part

Abstract: A stationary case has a resistive track. An elastic wiper is carried by a rotor mounted to rotate in the case and able, during operation, to rub against the resistive track, and a spring is placed between the stationary case and the rotor to pull the rotor to a rest position. The case provides at least one housing able to receive the wiper without initial stress or deformation in an initial position of introduction of the rotor in the case and to allow the wiper to come in contact with the track during mounting of the rotor in the case by rotation of said rotor between its introduction position and its rest position. Application is to measuring the angular position of the throttle valve of an internal combustion engine.

Abstract: A keyboard having keys activated by electrical contacts and the capacity to read one state from among four possible states, wherein the keyboard is a dipole disposed between two terminals between which are positioned in parallel three connectors, each including one of the electrical contacts, two of these connectors including diodes mounted anode to cathode, in such a way that the various states may be discriminated by means of the successive application of two reverse electrical voltages (V1, V2) to the terminals of the dipole and the corresponding detection of the logic states of the contacts using a logic detector.

Abstract: An output stage of a calculator (2) has a transfer function of the form: tc=N.TSD+.epsilon. where .epsilon. is a small and known quantity; t.sub.c is the conduction time of the coil, N is a number of angular fractions or periods of an interpolation signal; and TSD is the period corresponding to one tooth on the starter gear. The device comprises measurement means (1, 32, 36) for measuring the time strictly necessary to obtain the required energy; means (6, 9, 13, 17) for generating signals at each fraction of the angular marking signal in order to obtain a time measurement of a counting window and means (21, 25, 29) for counting and memorizing during this window an interpolation signal of the angular resolution n times higher.

Abstract: An electronic control circuit of the type including a microprocessor, a circuit for monitoring the operational state of the microprocessor connected directly to a first output of the microprocessor, and a warning light of the control circuit and its input and output peripherals. The warning light is connected to a second output of said microprocessor through a starter and protection circuit and thus diagnostic data are available in series at the input terminal of said warning light which is also the output of said starter and protection circuit.