Siemens Aktiengesellschaft

Erwin Sick Gmbh Optik-Elektronik

Steinheil Optronik Gmbh

Gerhard Krause

Werner Spaeth

A optoelectronic circuit arrangement, for instance for thermal viewing equipment, comprises a plurality of independent photodetector elements, whose signals are combined by multiplexers. The multiplexer output is connected with the common input of a switched integrator, which applies integrated signals to an output switch device, steps being taken to ensure that the multiplexer is at all times electrically separated from the output of the output switch device. For this purpose the integrator has at least one channel with three electronic switching members which in a cyclic sequence perform the operations of 'integration', 'output of integral value to output' and 'erase integral value'.

Spike-free optoelectronic amplifier having a multiplexer at all times

A circuit arrangement for infrared detectors, more especially for thermal viewing devices with photoresistors as detector elements is designed in order so as not to necessitate an input amplifier and an output amplifier for each detector. For this purpose the collector current of a transistor is integrated for a scan period in a capacitor and at the end of the scan period the capacitor is discharged through an electronic switch to a present potential.

Input amplifier for thermally viewing device with photoresistor

The present spectrometer features two modulators 11, 11' disposed one on either side of a dispersive member 19 which produces wavelength dependent deflections .alpha. of the various spectral components in the radiation. In other words the precise angle of deflection .alpha. is a function of wavelength. The dispersive element 19 is conveniently positioned between two lenses 26 which form a telecentric system with a magnification of one. The lens system is used to produce an image of the first modulator on the second modulator. Each of the modulators is preferably a grating with a linearly varying grating constant so that the modulators, which move in opposite directions f,f' at constant speed subject the incident radiation to a position dependent modulation. The radiation emerging from the second modulator 11' falls onto a photodetector 13. The arrangement is such that the output signal from the detector 13 contains a number of different frequencies each of which is characteristic of one of the particular spectral components. These frequencies, and thus the information on the individual spectral components can be readily separated using respective band pass filters 17.sub.I, 17.sub.II, 17.sub.III.

Apparatus for spectral analysis of a broad beam of radiation using a

A mixture of substances is analyzed by spectral analysis to establish the concentration of one component of the mixture. For this purpose signals U.sub.1 (.lambda.) representative of the spectrum of the substance under investigation and U.sub.2 (.lambda.) representative of the spectrum of the mixture of substances are manipulated electronically so as to remove the effects of cross-sensitivity and to yield an accurate value for the concentration of the substance in the mixture of substances. This concentration is normally difficult to determine because of the effects of cross-sensitivity, i.e. because other components in the mixture of substances have similar spectral lines to those of the substance under investigation. In one arrangement the two signals U.sub.1 (.lambda.) and U.sub.2 (.lambda.) are first differentiated in respective differentiating stages 13 and 14 and the differentiated signals are multiplied in a multiplier 17. The output signal from the multiplier is subsequently integrated in an integrator 20 and the output of the integration is a measure of the concentration of the substance under investigation. The signal F derived from the multiplier 17 has two components F.sub.N +F.sub.S. The component F.sub.N is a product of the wanted signal in respect of the substance under investigation from the reference source 11 and of the wanted component from the measured signal U.sub.2 (.lambda.). This product is always positive and thus leads to a maximum value at the output of the integrator. The component F.sub.S is equivalent to a product of the wanted signal from the reference source with unwanted signals from the measurement and is in fact a value which statistically flucutates about zero. The result of integrating this component is thus a value which approximates to zero. In other words the result of the integration provides exclusively information about the substance under investigation.

Arrangement for determining the concentration of a substance in a

Spectral analysis of a beam of radiation is carried out by splitting the beam of radiation into its respective spectral components and by applying a characteristic modulation to each of the spectral components before allowing them to fall on a common detector. The super-imposed signals generated by the detector and representative of the spectral components are then electronically segregated by reference to the characteristic modulations that have been applied to the individual spectral components. This is conveniently done by generating a series of modulated reference signals which have been modulated in exactly the same way as the spectral components of interest. The technique is not restricted to optical spectra but can also be used, for example, for X-ray spectra and mass spectra.

Spectral analysis of a beam of radiation

Apparatus for measuring the speed of flow of a flowable medium by determining the transit time of sound waves therein wherein first and second sound transmitter/receivers in the form of electroacoustic converters are spaced apart in the medium with an imaginary line joining said first and second transmitter/receivers having a component in the direction of the flow to be measured and wherein sound pulses of predetermined length are alternately transmitted in a first direction from said first transmitter/receiver to said second transmitter/receiver and in a second direction opposite to said first direction from said second transmitter/receiver to said first transmitter/receiver said sound pulses being converted into electrical measurement pulses on arrival at said transmitter/receivers there being processing circuitry for processing electrical measurement pulses to determine the speed of flow from the transit times of the sound pulses in said first and second directions, said processing circuitry including means for precluding from the determination electrical measurement pulses which do not conform to an expected pattern as a result of electrical or acoustic disturbances.

Apparatus for measuring the speed of flow of a flowable medium by

An optoelectronic coupler with a semiconductor transmitter and a semiconductor receiver has a transparent conductive screen formed of semiconductor material overlying the active area of at least one of the transmitter and receiver, in the path of optical radiation passing between the transmitter and receiver, and directly electrically connected to a semiconductor zone of the active area, to protect the coupler from changes in its electrical characteristics due to high intensity electric fields.

Screening electrodes for optical semiconductor components

An integrated semiconductor circuit arrangement includes active and passive function elements in a semiconductor body and a high frequency a.c. voltage is used as a supply voltage for the function elements. A highly doped semiconductor substrate of one conductivity type carries a weakly doped layer, for example, of the same conductivity which has zones of the opposite conductivity therein. The substrate functions as an emitter for a plurality of transistors of which the doped zones serve as bases. Spaced co-planar layer sections bridge the base zones and serve as collectors. The collectors are either metal layers or semiconductor layers and in either case are covered with an insulating layer which carries a conductive layer for connection to a high frequency supply.

A.C. supplied integrated semi-conductor logic circuit

A circuit arrangement is disclosed for the transmission of electrical supply outputs for low power devices which must be electrically separated from the mains supply. The circuit arrangement has at least one opto-electronic coupler with which low power can be transmitted with complete electrical separation. Accordingly, mains transformers can be replaced in low power operations.

Circuit arrangement for the transmission of electrical supply power

The dynamic input impedance of a feedback current amplifier is varied such that a matching to the characteristic impedance of a line feeding the amplifier is achieved. An integrated negative feedback current amplifier has at least two amplifier stages and one inverse coupling branch from the amplifier input to the amplifier output. The active element of the last amplifier stage has a divided output circuit such that the output current is divided between the inverse coupling branch and the amplifier output. The input DC current is selected such that the dynamic amplifier input impedance is adjusted to the characteristic impedance of a line feeding the amplifier.

Integrated amplifier with negative feedback

An opto-electronic coupler for signal voltages of &lt;1 V is provided in which the transmitter of the coupler is electrically separated from the receiver. In order to avoid a current supply device, there are provided two additional couplers connected in series and of opposite coupling direction to the first coupler. The additional couplers supply the necessary energy for a luminescent diode transmitter of the first coupler.

Opto-electronic two-way coupling

An integrated circuit degenerative feedback current amplifier has at least two amplifier stages and a degenerative feedback branch connected from the amplifier input to the amplifier output. An active element of the last amplifier stage has its output circuit subdivided in such a way that a subdivision of the output current results whereby a first partial current is guided via the degenerative branch and a second partial current is guided into the amplifier output.

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Rosenheim, Germany

Gerhard Krause