SU568213A1 - Photomultiplier response stabilizer - Google Patents

Description

(54) SENSITIVITY STABILIZER OF PHOTO-MINATOR

one

This invention relates to automatic sensitivity adjustments of a photomultiplier and a mohset used in digital photo guides and light spot displacement meters,

The stabilization sensitivity of a photomultiplier of a tracking system is known, in which the level of low-frequency continuous AC signals is stabilized by an appropriate effect on a controlled attenuator. producing a level limiting signal amplitude ij.

However, the lime stabilizer cannot be used to stabilize the sensitivity of the photomultiplier in a pulsed mode.

Also known is the sensitivity stabilizer of the photomultiplier of the tracking system, which contains the optical system, a half-disk modulator installed between the optical system and the photomultiplier, and a controlled attenuator, at the input of which a signal from 410 Tou multiply.

However, this stabilizer has a low sensitivity control accuracy.

The purpose of the inventions is to increase the sensitivity control accuracy.

To do this, a photomultiplier sensitivity regulator containing an optical system, a half-disk modulator installed between the optical system and a photomultiplier, and a controlled attenuator, to the input of which a signal from the photomultiplier is fed, two valves are added, a sum counter and a block of logic elements And, the first valve connected between the output of the photomultiplier and the input of the controlled attenuator, the second valve is connected between the output of the photomultiplier and the input of the summing counter, the outputs of which through the logic x AND elements are connected to the inputs of a controllable attenuator. Moreover, the controlled attenuator can be made in the form of a pulse counting adder-divider.

The drawing shows a structural electrical photomultiplier sensitivity stabilizer circuit.

Claims (2)

The device contains an optical system 1. a half-disk modulator 2, installed between the optical system 1 and a photomultiplier 3 with a pulsed silicate, a discriminator and a former, controlled by an attenuator 4, the input of which is given a signal from a photomultiplier 3, two gates 5, 6, a summing counter 7 on Tl TP of bits and block 8 of logic elements And, with the first valve 5 connected between the output of the photomultiplier 3 and the input of the controlled attenuator 4, the second valve is connected between the output of the photomultiplier and the input of the adding counter 7, output 8 through which the block is connected to the inputs of a controllable attenuator 4, and the controllable attenuator 4 is in the form of countable pulse adder-divider comprising ttt bits. The device works as follows. When the valve 5 is open during the Tvrvgmeni T, the pulses from the signal output of the photomultiplier 3 (the output of the pulse shaper) are fed to the summation counter 7, where the binary code of the number proportional to the average for the period of the pulse frequency at the load is recorded, the scale of the light intensity flow). At the minimum brightness of the spot for a time T through the open valve 5, the TI of the lower bits of the summing counter 7 is filled. At the maximum brightness, all the (AND + TP) bits are filled. At the end of time T, when a command is received from a half-disk modulator unit 2, the inverse code of the number recorded in the upper bits of summing counter 7 is transmitted (1 to ttt) of the controlled attenuator 4, after which time T through the open valve 6, the pulses are summed from the output of the photomultiplier 3 to the complete filling of the controlled attenuator 4. An overflow pulse passes to the output of the device, at the same time providing repeated input — „o, g,“ - of the reverse code of the number recorded in the sum -, r, rue meter 7. Then again performs with the summation of pulses in the controlled one. Attenuator 4 to overflow pulse output. The pulses from the output of the photomultiplier 3, with the valve 6 open, will be divided by the number recorded in the upper bits of the counting counter 7, plus one. Valves 5 and 6. are opened, respectively, in odd and even periods of rotation of the half-disk. As a result of dividing by a number proportional to luminance, the average pulse frequency at the output of the device in discrete: .ie time intervals T, T T ,,. remains unchanged, and its change within one period of rotation of the half-disk (T,,..) carries information about the spot displacement from the optical axis. When the brightness of a light object changes, the sensitivity of the device remains stable, since during the working period (T2, T. ,,) the same number of pulses will always pass to the output of the controlled attenuator 4. Thus, using this device, the time constant of changing the brightness of a light object is significantly less than the time of the photomultiplier power supply circuit (by several orders of magnitude), the range of operation of the stabilizer is determined by the operating range of the photomultiplier and pK (X; the spot may vary | C. The maximum speed of the device is determined by the frequency of rotation of the half-disk of the half-disk modulator 2 (i), and by alternately entering the scale of brightness and measuring the offset by light-blue spot frequency of changing the brightness of the object is not up to false exceed-4- (for example, with f 2OO Hz, the maximum device speed is 10 O Hz, and in a known device it is Hertz fraction). Invention 1. Photomultiplier sensitivity stabilizer containing an optical system, a half-disk modulator installed between the optical system and a photomultiplier, and a controlled attenuator, at the input of which a signal was sent from the photomultiplier, characterized in that, in order to increase the sensitivity control sensitivity, two gates were inserted in it, a summation counter and a block of logic elements And the first valve is connected between the output of the photomultiplier and the input of the controlled attenuator, the second valve is connected between the output of the photomultiplier and the input of a summing counter, the outputs of which are connected through a block of logic elements AND; the inputs of the controlled attenuator, o / - yy, i. The sensitivity stabilizer of the photomum t nozhelep under item 1, characterized in that the controlled attenuator is designed as a pulse counting adder-divider,. Sources of information taken into account in the examination: 1. US Patent No. 31323О8, cl. 33 O144, O5.05.64. 2.Burov A. F, et al. Electric drive and control systems. M., Science, 1966, p. 131