RU1805301C - Photometer - Google Patents

Abstract

SUMMARY OF THE INVENTION: A photometer, comprises a photoconverter with a frequency output, a direct counter, a first AND element, a timer, first and second pulse shapers, a register, a decoder, a digital indicator. The photoconverter contains a BISPIN device, a resistor, a switch. A trigger and a second element I are introduced. The photoconverter further comprises a photodetector, a capacitor, and a pulse shaper. 1 ill.

Description

The invention relates to optoelectronic and measuring techniques and can be used to photometer emissions from any region of the optical range having a wide dynamic power range.

The purpose of the invention is to expand the scope.

The drawing shows an electrical diagram of the device.

The device comprises a light-frequency photoconverter 1 having an optical input 2 and an electric output 3, a direct counter 4, an element And 5 timer 6, the first 7 and second 8 pulse shapers, register 9, decoder 10, digital indicator 11, trigger 12, the second circuit 13, the photoconverter 1 comprises a photodetector 14, a bispin device 15, a switch 16, a load resistor 17, a pulse former 18, a capacitor 19. wherein the optical input 2 of the photoconverter is the optical input of the device and is optically coupled to the aperture of the photodetector 14, ne the first electrode of which, together with the first output of the load resistor 17 is connected to the power bus 20, the second electrode of the photodetector 14 is connected to the terminal 21 of the substrate of the bispin device 15, with the first electrode of the capacitor 19 and with the input 22 of the switch 16, the output of which 23 is connected to the common bus 24 with which the second capacitor electrode 19 and the locking contact 25 of the bispin device 15 are also connected, the ohmic contact 26 of which is connected to the second electrode of the load resistor 17 and to the input of the pulse shaper 18, the output of which is connected to the control electric house 27 of the switch 16 and is the electrical output 3 of the light-frequency converter 1, which is connected to the first input of circuit I 5, the second input of which is connected to the output of timer 6 and the inputs of the first 7 and second 8 pulse shapers. Circuit output And 5 connected to the account in

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with the input 28 of the counter 4, the parallel load input 29 of which is connected to the output of the first 7 pulse shaper and with the installation input 30 to the trigger unit 12, the initial code is set at the parallel inputs 31 of the counter 4. The outputs of the counter 4 are connected to the parallel inputs of the register 9, the output 32 of the transfer of the counter 4 is connected to the input of the installation 33 to the zero of the trigger 12, the output of which is connected to the first input of the second element 13 AND, the second input of which is connected to the output of the second pulse generator 8 and the input 34 parallel loading of the register 9, the parallel outputs of which are connected to the inputs of the decoder 10, the outputs of which are connected to the inputs of the digital indicator 11, the output of the second circuit And is connected to the reset input 35 of the register 9.

The device operates as follows ... . . g

In the absence of input radiation at the input 2 of the device, the dark current of the photodetector 14 does not charge the capacitor 19, because compensated by the leakage currents of the transition, the substrate 21, the locking contact 25 of the bispin device 15 and the leakage currents of the open switch 16. In this case, the bispin device 15 is in a closed state, therefore, at the input of the pulse shaper 18, which performs the function of an inverter-amplifier, high potential, and at its output, a low potential, which holds the switch 16 in the open state and is present at the output 3 of the photoconverter 1 illumination-frequency. In this case, there are no pulses at the counting input 28 of the counter 4. On the leading edge of the unit time interval of duration T from the output of the timer 6, the first shaper 7 generates a short pulse for recording the initial code from the inputs 31 of the counter 4. The same pulse will set the trigger 12 to a single state. Since there is no radiation at input 2, there will not be a single pulse in counter 4 during the time T, therefore, at the end of the interval T from the output of timer 6, the second driver 8 will generate a short pulse, which will pass through the second circuit And 13 (since the output of trigger 12 unit) will go to the reset input 35 of register 9 and will reset it, which will lead to the display in the next cycle (display cycle) of a zero value on the digital indicator 11.

When the input 2 is exposed to radiation, the resistance of the photodetector 14 decreases, the charge current of the capacitor 19 and the intrinsic capacitance of the junction of the bispin device 15 flow from the supply bus 20 through the photodetector 14. When the potential at the capacitor 19 reaches the potential of the ohmic contact 26, the bispin the device 15 goes into a conducting state, while the potential of the ohmic contact 26 decreases to almost zero, i.e. on the ohmic contact 26 of the bispin device 15, a zero potential pulse is generated which corresponds to a high potential pulse at the output of the pulse generator 18, which (pulse) closes the input 22 of the switch 16 with its output 23, the discharge speed of the capacitor 19 and the capacitance of the bispin device 15. - The communication organized by the driver 18 and the switch 16 allows you to shorten the trailing edge of the generated pulses. After the capacitor 19 is discharged, the bispin device returns to the closed state, the switch 16 opens and the described process is repeated. The pulse frequency f at the output 3 of the photoconverter 1 is directly proportional to the input power W, since

 + b, (1) where k and b are coefficients. Since the frequency f is nothing more than the number N of pulses per 1 s, expression (1) will be rewritten

N-k W + b. (2) To get the value of W from (2), we write

 b

k k

(3)

N / k is nothing more than the number of pulses in the k-th part of a second. The hardware implementation of calculation (3) is based on the counter 4, in which, before the start of the measurement cycle, an additional code of the number (-v / c) is entered with input 31, in other words, the value (V -v / c), where V is the capacity of the counter 4 And then, during the measurement cycle with a duration of T 1 / k s, generated by timer 6, the pulses from the output 3 of the photoconverter 1 go to the counter 4 through the I circuit 5. As a result, in the counter 4 we get a code number proportional to W. When counting the pulses from the output 3 photoconverters 1 counter 4, at its output 32

a pulse is generated which sets the trigger 12 to zero.

At the end of the interval T, the second driver 8 will generate a pulse that will not pass to the input 35 of the reset register 9 (since

trigger 12 at zero), but affects the input 34 of parallel loading of register 9, which leads to overwriting of the code from counter 4 into register 9, which is then decrypted by decoder 10 into control signals of digital indicator 11. On the front

On the edge of the next pulse of timer 6, an additional number code (-v / c) will be set in counter 6, and the trigger will be set to one and the measurement process will be repeated. The energy value of the input radiation, measured in the current period, is displayed during the subsequent period of operation of the timer 6.

The coefficients k and b in formula (1) are determined experimentally from the constructed watt-frequency characteristic of the photoconverter 1.

For reliable operation of the photoconverter 1, it is necessary that the potential accumulated on the capacitor 19 is several (0.1-0.2 V) higher than the potential of the ohmic contact 26 of the bispin device 15. For this, the first electrode of the photodetector 14 can be connected to a voltage source slightly higher than the supply voltage supplied to the load resistor 17.

When a photodiode 14 is used as the photodetector 14, the photo converter 1 reliably works when the resistor 17 and the photodetector 14 are supplied with the same supply voltages to the first electrodes.

,, Changing the capacitance of the capacitor 19, you can shift the output frequency range of the photoconverter 1 illumination-frequency.

SUMMARY OF THE INVENTION A photometer comprising a photoconverter, illumination — frequency, direct counter, first AND element, timer, first and second pulse generators, register, decoder, digital indicator, the output of the photoconverter is connected to the first input of the And circuit, the output of which is connected to the counting counter input, the second input of circuit And is connected to the timer output and the inputs of the first and second pulse shapers, the output of the first pulse shaper is connected to the input of the counter parallel load with the initial code to the parallel Yelnia inputs and outputs of the counter are connected to the parallel register vho- 5 rows, parallel load input coupled to an output of the second pulse shaper, the register outputs are connected to inputs of a decoder, which outputs are connected to inputs of a digital

0 indicator, while the photoconverter contains a bispin device, a load resistor, a switch, and the substrate of the bispin device is connected to the input of the switch, the output of which is connected to a common bus. about

characterized in that, in order to expand the scope of application, a trigger and a second element And are additionally introduced into it, and the counter transfer output is connected to the installation input in the trigger O,

0 the input of the installation in 1 of which is connected to the output of the first pulse shaper, and the direct output of the trigger is connected to the first input of the second element And, the second input of which is connected to the output of the second

5 pulse shaper, the output of the second circuit And is connected to the reset input in the O register, and the photoconverter additionally contains a photodetector, capacitor and pulse shaper, and

0 the first output of the photodetector is connected to the supply bus, and the second output to the output of the substrate of the bispin device, the input of the switch and the first output of the capacitor, the ohmic contact of the bispin device is connected to the input of the pulse former and through the load resistor to the supply bus, which locks the bispin contact device and the second output of the capacitor - with a common bus., no, pulse shaper output

0 is connected to the control input of the switch and is the electrical output of the photoconverter, and the optical aperture of the photodetector is the optical input of the photoconverter.