The electronic unit photometric detector
The invention relates to the field of high-performance liquid chromatography. Essence: the electronic unit photometric detector includes a photodetector, the inverter current of the photodetector into a voltage multiplying digital to analog Converter, analog-to-digital Converter and a microcontroller. Inputs/outputs the first port of the microcontroller bitwise connected to the digital inputs/outputs analog-to-digital Converter, an analog input connected to the output of the multiplying digital to analog Converter, the digital inputs which bitwise connected to the outputs of the second port of the microcontroller and analog input is connected to the inverter output current of the photodetector into a voltage, an input connected to the output of the photodetector. The technical result - the reduction of the noise level while maintaining low error and drift. 1 Il.The invention relates to the field of high-performance liquid chromatography.Known electronic unit photometric detector , containing a working sensor, reference sensor, the Converter current work of the photodetector into a voltage, a current transducer opasnostjami are the high level of uncertainty and drift, there is no perfect matching characteristics of the working and reference photodetectors.The closest to the technical nature of the claimed device is selected as a prototype of an electronic unit photometric detector , which contains the sensor, the Converter current of the photodetector into a voltage analog-to-digital Converter and a microcontroller, the output of the photodetector is connected to the input transducer of the photodetector into a voltage, the output of which is connected to the analog input of analog-to-digital Converter, digital inputs/outputs which bitwise connected to inputs/outputs of the first port of the microcontroller.This electronic unit has small values of error and drift, as a worker, and the reference luminous flux alternately served on the same photodetector. However, its disadvantage is the weak suppression of low frequency noise of the photodetector due to the fact that the cutoff frequency of the Converter current of the photodetector into a voltage and an analog part analog-to-digital Converter must be significantly higher than the modulation frequency of the light flux (typical value of which is equal to 12.5 Hz).Task is okresnosti and drift.This is achieved in that the electronic unit photometric detector containing the sensor, the Converter current of the photodetector into a voltage analog-to-digital Converter and a microcontroller, the output of the photodetector is connected to the input transducer of the photodetector into a voltage, and the digital inputs/outputs a / d Converter bitwise connected to inputs/outputs of the first port of the microcontroller, provided with a multiplying digital to analog Converter, an analog input connected to the inverter output current into a voltage, digital inputs bit-wise connected to the outputs of the second port of the microcontroller, and the output connected to the analog input of analog-to-digital Converter.The invention is illustrated "blueprints", which shows the structural diagram of the electronic unit photometric detector. The device comprises a photodetector 1, the Converter current sensor voltage 2, multiplying d / a Converter 3, an analog-to-digital Converter 4 and the microcontroller 5, the inputs/outputs of the first port bitwise connected to the digital inputs/outputs analog-to-digital Converter with 4 analog input which is tive to the outputs of the second port of the microcontroller 5, and the analog input is connected to the inverter output current of the photodetector into a voltage 2 input connected to the output of the photodetector 1.The electronic unit photometric detector works as follows. Using optical-mechanical detector (not shown) on the photodetector 1 in turn serves the working and the reference light streams. It converts the intensity into electric current. The Converter current sensor voltage 2 converts this current into an electrical voltage, which, through the multiplying d / a Converter 3 is supplied to an analog-to-digital Converter 4. Through the multiplying d / a Converter 3 is multiplied subject to analog-to-digital conversion of the voltage is stepped suppressing the weight function (EOF) in accordance with the expressionwhere U2(t), U3(t) - output voltages respectively of the Converter current sensor voltage 2 and multiplying digital to analogue Converter 3;n is the number of stages EOF;i(t) is the unit function, equal to 1 at the (i-1)T<tiT and 0 otherwise;When this weighting coefficients wiare fed to the digital inputs of the multiplying digital to analogue Converter 3 outputs the second port of the microcontroller 5.Analog-to-digital Converter 4 converts the digital code average over the time interval PT values of the voltage U3(t). The numeric equivalent of the output of the code is described by the following expression:where K is a constant coefficient;w(t) - EOF generated by the multiplying digital to analogue Converter 3.Process control analog-to-digital conversion is performed by the microcontroller 5. It also synchronizes the beginning of the cycles of formation of EOF and analog-to-digital conversion with the switching times of the luminous flux. Thus, the numeric equivalent of the output code of the analog-digital Converter 4 is directly proportional to the intensity of the light flux received on the photodetector 1 during the current conversion cycle.The results of the analog-to-digital conversion of the intensities of the working and the reference light fluxes received at the microcontroller, through which calculates the optical density.Weight FCP is allowing EOF  allows to suppress noise of the photodetector 1 in several thousand times in the frequency range from (2...3)/TPto infinity (where TP is the duration of the interval of supply of the working or reference luminous flux at the input of the photodetector 1). A similar suppression in the absence of the weight averaging due to the filtering properties of the Converter current sensor voltage 2 and analog-to-digital Converter 4 is possible only in the frequency range from 30...40)/TP.Thus, this device allows for a significant decrease noise while maintaining the possibility of modulation of the light flux, and consequently, low values of error and drift.
ClaimsThe electronic unit photometric detector containing the sensor, the Converter current of the photodetector into a voltage analog-to-digital Converter, microcontroller, I/o port which is the bitwise connected to the digital inputs/outputs analog-to-digital Converter, the output of the photodetector is connected to the input transducer of the photodetector into a voltage, characterized in that it has a multiplying digital to analog Converter, an analog input connected to the inverter output current into a voltage, digital inputs bit-wise connected with the indicator.
FIELD: laser technology.
SUBSTANCE: device for testing parameters has focusing system, set of calibrated diaphragm installed in focal plane of focusing system and photoreceiver. Unit of calibrated diaphragm is provided with first shift mechanism. Device also has analog-to-digital converter, controller, and control unit, registering unit, unit for spatial guidance and unit for selecting commands. Focusing system has variable value of focal distance and with permanent position of focal plane. Focusing system has TV objective and optical system, which is provided with second shift mechanism. First shift mechanism is made in form of two-coordinate scanning device. Focusing system with unit of calibrating diaphragms, photoreceiver and command selection unit are made in form of integral optical head provided with spatial guidance unit. Personal computer provided with display is used as registering unit.
EFFECT: widened functional abilities; improved precision of measurement.
FIELD: semiconductor electro-optics; luminous radiation receivers.
SUBSTANCE: photoreceiver can be used for creating atmospheric optical communication lines, in particular, for creating moving objects tele-orientation laser systems, for example, monitored rockets. Photoreceiver has capacitor, first transistor, photodiode and power supply. Photodiode is connected to collector circuit of the first transistor and capacitor is connected to base of the first transistor. Photoreceiver also has non-inverting amplifier, non-linear band filter, second transistor, first to third resistors and blocking capacitor. Second output of the capacitor has to output of photoreceiver. Cathode of photodiode is connected with input of non-inverting amplifier which has output connected with input of non-linear band filter, with base of second transistor, with second resistor and blocking capacitor. Second output of second resistor is connected with bas of first transistor, which has emitter circuit where first resistor is brought up. First resistor is connected with power source and emitter of second transistor. Output of non-linear band filter is connected with cathode of photodiode and collector of second transistor through third resistor.
EFFECT: improved sensitivity; widened dynamic range of photoreceiver.
FIELD: measurement technology.
SUBSTANCE: invention is based upon conversion of signal of charge being multiple to charge of single-photon pulse to voltage. Converter signal is stored in analog form in preliminary signal processing unit non-depending on value of registered signal. Procedures mentioned above are repeated many times and cyclically and results are summed subsequently. Scale of scale-plate of analog-to-digital converter is chosen in correspondence with statistical parameters of photo-electronic multiplier and analog-to-digital converter. To reduce redundancy of data transmission the analog-to-digital converter is chosen to have non-uniform sampling interval scale.
EFFECT: widened dynamic range; simplified design; cost reduction.
2 cl, 5 dwg
FIELD: semiconductor electro-optics; light radiation sources.
SUBSTANCE: photoreceiver has photodiode, which has one output connected with power source of photodiode and the other one is connected with resistance of load and with input of preamplifier, controlled divider, voltage amplifier, signal detector, integrator and detective comparator provided with reference voltage supply. Controlled divider is connected between output of preamplifier and with input of voltage amplifier. Output of the latter is connected with input of signal detector and with first input of detective comparator. Device also has additional amplifier, noise detector and amplitude signal detector. Preamplifier is made to be controlled. Integrator has two inputs and it is provided with reference voltage supply, which source is connected with its non-inverting input. Non-inverting input of additional amplifier is connected with output of voltage amplifier. Output of additional amplifier is connected with input of noise detector. Inverting inputs of integrator are connected with outputs of noise detector and of signal detector correspondingly. Output of integrator is connected with input of preamplifier. Input of amplitude signal detector is connected with output of voltage amplifier. Output of amplitude detector is connected with control input of controlled divider and with second input of detective comparator. Reference voltage source is connected with its first input.
EFFECT: improved noise immunity when parasitic signals and optical noises are present.
SUBSTANCE: device consists of a bias voltage generator (9), the input of which is connected to the output of the control unit (8), and the output of which is connected to an avalanche photodiode (11), and a comparator (12). The control unit has extra elements for controlling bias voltage, operation threshold and time for switching on and off comparator (12) of photoelectric pulses. The output of elements for controlling operation threshold and on and off switching time is connected to the inputs of comparator (12), and the output of comparator (12) is connected to the input of the generator (14) of output pulses.
EFFECT: complete or partial suppression of undesired electrical pulses.
FIELD: physics, measurement.
SUBSTANCE: invention refers to measurement technology and physics and can be used for single pulse control. The device contains passive transducer 1 connected to transducer amplifier 2, monostable circuit 3 with driving input 4, three operational amplifiers 5, 9 and 18, noninverting operational DC or AC voltage amplifier 16, three diodes 6, 7 and 25, two analogue switches 8 and 15, resistors 10, 12, 13, 19-23, RC circuit 11, capacitor 24, active or passive L-type high-pass RC filter 14.
EFFECT: extended dynamic range and higher noise immunity.
2 cl, 3 dwg
SUBSTANCE: device includes a photodetector - multiskan which has a set of counter-connected p-n junctions, divider and common buses, optical system for formation of a light spot on the surface of the multiskan photodetector from a radiation source, a current-voltage converter connected to the common bus of the multiskan, a recording device, a power supply connected to the divider bus of the multiskan and an integrator which has an integrating capacitor in a feedback circuit, and a centre point in the power supply. Resistance Rf of the feedback circuit of the current-voltage circuit is greater than resistance Rint in the input circuit of the integrator circuit by K times, where 1<K K≤100. The device also has an external source of pulsed voltage and an electronic switch connected by the input electrode to the input of the integrator and by the output electrode to the output of the integrator, and by the control electrode to the external source of pulsed voltage. The recording device is connected to the output of the integrator. The invention enables generation of output voltage which is applied across the centre point of the power supply due to charge of the integrator capacitor through voltage formed at the output of the current-voltage converter. As a result, value of current which charges the integrating capacitor can increase by K=Rf/Rint times, where 1<K≤1000, by selecting values of Rf and Rint which shortens the time for formation of output voltage which corresponds to the coordinate of the light spot by K times. After taking readings, recharge of capacitance of p-n junctions of the multiskan can be stopped.
EFFECT: prevention of development of transient processes and more accurate measurement of the position of a light spot.
1 dwg, 1 ex
SUBSTANCE: device has a photodiode 1, a voltage follower 2, a switch 3, a variable resistor 4, a sampling and storage device 5 and a switch control device 6.
EFFECT: invention enables to keep sensitivity of a photodiode constant when ambient temperature changes and increases functional reliability, wherein the photodiode works in a mode with maximum sensitivity and high operation speed.
SUBSTANCE: device has a photodiode, a differential amplifier, a power supply, a variable resistor, a voltage source, an analogue-to-digital converter and a computing device. The output of the device is the output of the differential amplifier.
EFFECT: high accuracy of measuring temperature of heated surfaces by reducing the effect of emissivity of the radiating surface of the inspected object and reducing the effect of transfer constants of the amplification and conversion circuits, high linearity of conversion while maintaining a dynamic range without deterioration in sensitivity of the device in a wide range of operating temperature of the photodetector.