Abstract: A multiplexed filter with n channels comprises at least one amplifier G.sub.2 with n feedback capacitors C.sub.5 to C.sub.8 associated with the switches S.sub.5 to S.sub.8. A switch-controlled resistance R.sub.2 (C'.sub.r, K.sub.5, K.sub.6, K.sub.7, K.sub.8) is connected to its input. Switching signals .phi..sub.i and .phi..sub.p out of phase with each other are supplied to the switches K.sub.5 to K.sub.8 while the multiplexing signals .phi..sub.1 to .phi..sub.4 are applied to the switches S.sub.5 to S.sub.8. The signal .phi..sub.1 has a period T.sub.1 and the signals .phi..sub.2 to .phi..sub.4 have periods T.sub.i =2.sup.(i-1) T.sub.1 where i=2 to 4. The period T.sub.1 is twice the period of .phi..sub.i and .phi..sub.p and the time intervals of all of T.sub.1 to T.sub.4 are equal to the period of .phi..sub.i and .phi..sub.p. This filter with n band pass ranges (n=4 in this example) can serve with advantage for the frequency analysis of an electrical signal delivered by a microphone.

Abstract: A quartz thermometer which emits a signal, the frequency of which is a substantially linear function of temperature. The thermometer comprises a quartz resonator provided with electrodes disposed on the margins of the upper and lower main surfaces, parallel to the length direction. The electrodes are supplied with electric current so as to cause the resonator to vibrate torsionally. The length of the resonator is substantially parallel to the X axis of the quartz crystal. An electronic circuit is responsive to the signal emitted by the resonator for producing an output representative of temperature.

Abstract: There is disclosed blood pressure measuring equipment comprising a sleeve with a chamber inflatable by fluid and a measurement transducer for determining the circumference of an arm to which the sleeve is attached. A pressure sensor is provided to detect pressure in the chamber and is electrically connected through electronic components with two analog stores for storage of measured pressure values representing systolic and diastolic blood pressure. An indicating control device is connected between the stores and a digital display unit and comprises a pressure value correcting device by means of which the pressure values can be corrected, in dependence on the circumference of the arm as determined by the transducer, during readout of the stores. As a result, errors in the pressure values due to different arm circumferences can be eliminated.

Abstract: A passive electro-optical display cell comprising, on the internal face of each of its plates, at least one of which is transparent, sets of control electrodes and sets of screen electrodes, the control electrodes and the screen electrodes being separated by an insulating layer. The screen electrodes and the insulating layers have apertures therein facing the control electrodes. In order to reduce the number of conducting tracks, the cell is controlled by multiplexing. This type of control is made possible by virtue of the particular combination of the control electrodes and the screen electrodes. The control and screen electrodes of either plate will select two segments for display, but a selection between the two segments is made possible because they face different screen electrodes of the other plate. Such a cell makes it possible to display more data than a normal cell and may be used in an electronic watch which has a large number of functions.

Abstract: A liquid crystal display cell with thermal compensation of the degree of contrast comprises a measuring capacitor 12, 13 and a reference capacitor formed by two constituent reference capacitors 13, 15 and 14, 15 connected in series. The areas of the surfaces of the electrodes are so selected that the capacitances of the measuring and reference capacitors are approximately equal. The measuring and reference capacitors of the cell can be operated by excitation voltages of the same amplitude. The voltages which then appear at the terminals of the constituent reference capacitors are of lower amplitudes, corresponding to a region of the characteristics in which the capacitance is independent of temperature.

Abstract: A C-MOS oscillator circuit having input and output terminals adapted to be connected to a resonator and two active MOS transistors of complementary types connected in series between the supply terminals of the circuit, which supply terminals are connected to the positive and negative poles of a source of d.c. voltage, the sources of the transistors being connected to a supply terminal and the drains being connected to the output terminal. The d.c. bias and the a.c. voltage control of each of the active transistors are ensured by a MOS transistor of the same type connected as a diode between its gate and its drain, a current source connected between its gate and the supply terminal to which the source of the other active transistor is connected, and a capacitive voltage divider which is connected between the supply terminal, to which its source is connected, and the input terminal, and the intermediate point of which is connected to its gate.

Abstract: The liquid crystal-base composition for an electro-optical device contains an anthraquinone pleochroic coloring agent of formula (I) as defined in claim 1, that is to say, with in particular at least one hydroxy or amino group in position 1 and a heterocyclic side chain which is directly substituted in position 2, or 2 and 6, or 3, or 3 and 7.The compounds (I) have a high order parameter and are stable, thereby imparting to the compositions the properties required for use thereof for example in a display device.