摘要:
A circuit for measuring variations in the capacitance of a variable capacr forming part of a sensor includes an oscillator which generates an alternating signal which is supplied to two branches of a detection bridge. The first branch includes the variable capacitor connected in series with a variable capacitance diode. The second branch includes a capacitor connected in series with a variable capacitance diode. A differential stage has each of its in puts connected to the common point of a respective one of the branches. Synchronous demodulation means connected to the oscillator, are connected to the output of the differential stage for delivering a DC unbalance voltage Ve which is injected by a feedback line to the common point of the first branch, thereby continuously balancing the detection bridge.
摘要:
A circuit for controlling the lines of a display screen and including a t means with a single output is disclosed. The test means includes a single test control line (LCT), a single test output line (LST) and a plurality of sample holders (CEBj) and associated gates (Pj) and switches (Ij). The output voltage of the sample holders is transmitted onto a test output block (ST).
摘要:
A laser for use in all fields of measurement using a heterodyne effect delivers two waves at different frequencies, having mutually orthogonal linear polarizations. It comprises a lasing medium placed in a laser resonating cavity defined by mirrors and a birefringent crystal placed on the path of the two waves. The lasing medium is located in the resonating cavity in a zone where the two waves are separated spatially. Two quarter wave plates, one of which has neutral lines at substantially 45.degree. from the polarization axes of the birefringent means, are placed in the common path of the two waves so as to give a helical polarization to the two waves between the plates.
摘要:
A videotex terminal capable of receiving telecopies is disclosed, comprising a printing device at the output of its modem for printing fixed images in response to graphic data from a source connected to the telephone network, and the procedure for communicating the graphic data comprises protocol phases, during which the terminal and the source exchange questions and answers in the form of data transmitted at a first speed via the modem used alternately in one direction and in the other, and transfer phases, during which a flow of graphic data is transmitted by the modem, at this first speed, from the source to the terminal and data for regulating said flow are transmitted by the modem, at a second speed, from the terminal to the source.
摘要:
The accelerometer is suitable for use on missiles subjected to high acceltion forces on start. It comprises a base and a flat pendulum mounted on the base for oscillation about a rotation axis located in the plane of the pendulum. The distance between the center of gravity of the pendulum and the rotation axis is small as compared with the span of the pendulum. Electrodes are carried by a face of the pendulum on both sides of the axis and cooperate with electrodes carried by the base for generating an electrostatic balancing field. The pendulum has electrodes on one face only and that results in easier construction.
摘要:
A printing assembly which is adapted for printing on a print medium in a m of a sheet or tape includes a printing cylinder on which is wound and urged the print medium during a printing operation. A printing device prints on the print medium and urges it against the printing cylinder. An advancing device upstream of the printing device serves to advance the print medium and a tensioning device downstream of the printing devices tightens the print medium against the printing cylinder. The tensioning device includes two contra-rotating rollers having substantially smooth outer surfaces in contact from opposite sides of the print medium which allow sliding at the contacting surfaces and which provide for tensioning of the print medium on the print cylinder. The rollers are of the same diameter and are both motorpowered and driven at the same rotational velocity, which rotational velocity is greater than the advance velocity of the advancing device. The tensioning device also includes a mechanism for pulling the rollers elastically towards each other with forces which are substantially constant and identical.
摘要:
A fire control system for a weapon having an operator-aimed barrel compri a sighting piece carried by the barrel and having a reticle adjustable in position with respect to the bore axis of the barrel. A camera fast with the barrel has a field coaxial with the bore axis. The apparent movement of the target in the field of the camera is measured as well as the angular movements of the barrel by the operator. The position to be given to the reticle is computed from variations of the aiming direction of the barrel and from the apparent movement and the position of the reticle is consequently adjusted. The reticle may consist of a LCD.
摘要:
The cartridge comprises two arms situated on both sides of the cartridge y; each arm can occupy either a first, non-functional position (or storage position of the cartridge) or a second, functional position (or use position of the cartridge). Elastic tension means are provided to act on the ribbon to hold the latter taut whatever the functional or non-functional position occupied by the arms.
摘要:
Gyrocompass for sea vehicle comprising a pendular mechanism (2) with two dans, namely a rolling cardan (4) and a pitching cardan (5), a vertical fork (7) free to cooperate with said pendular mechanism (2), a site cardan (9) carried by said fork (7), a gyroscope with two degrees of freedom (11) carried by said site cardan (9), so that one of the two sensitivity axes (G.sub.z) is vertical, the other sensitivity axis (G.sub.y) being parallel to the axis of the site cardan (9), and its rotation axis (S) is horizontal, a horizontality sensor (12) carried by said site cardan, so that its sensitivity axis (P) is parallel to the rotation axis (S) of the gyroscope (11).
摘要:
The invention relates to devices for measuring the azimuth and the slope of drilling line. These devices comprise, in a container 1, a gyroscope 5 having two principal axes of sensitivity X--X and Y--Y and an accelerometer 12 having two principal axes of sensitivity parallel to those of the gyroscope 5; this gyroscope 5 is connected to a circuit to determine the component of the Earth's rotation vector along the axis of the drilling line.