SU1166349A1 - Method of supplying power to hollow-cathode valve - Google Patents

Abstract

POWERING METHOD OF A LAMP WITH A HALF CATHODE, in which the main current pulses are supplied to the lamp, as well as an additional current, characterized in that, in order to increase labor productivity during spectral measurements by increasing the speed of the hollow cathode lamp, , while measuring the magnitude of the luminous flux when it is reduced, compared with the magnitude of the luminous flux corresponding to the additional current, fix the moment of equality of the fluxes and include an additional current, measure the conducted The magnitude of the light flux, when it is increased, fixes the moment when the flux reaches a steady-state value and turns off the additional current. Od CO 4 ;: with fff f ff

Description

. The invention relates to electrical engineering and can be used to power spectral, lamps in special photometry, for example, in atomic absorption and agon fluorescent devices. The purpose of the invention is to increase the productivity of spectral measurements by increasing the speed of a hollow cathode lamp. This goal is achieved by using the noJibiM cathode tubes, which supply the main current pulses to the lamp as well as the additional current, the latter is fed as pulses, while measuring the magnitude of the luminous flux as it decreases, is compared with the magnitude of the luminous flux, corresponding to the additional current, fixes the moment of equality of the fluxes and includes an additional current is measured by the magnitude of the light. When this flow is increased, they fix the moment when the flow reaches a steady-state value and turn off the additional current. FIG. t is the block diagram of the device that implements: the power supply of hollow cathode tubes; in fig. 2 - time diagrams of the currents. The device contains an open receiver whose output is connected to unit 2 for measuring the output voltage of the photo receiver 1, the first output of unit 2 connected to the inputs of keys 4 and 5, the output of switch 4 is connected to the input of memory 6, the first input 7 of the comparison unit, the output of which is connected to the first input 9 of the trigger 10. The second input 11 of the trigger 10 is connected to the second output 12 of the unit 2. The key 3 is connected to the second input 13 of the comparison unit. The output of the trigger 10 is connected to the input of the generator 14 of additional current pulses, the output of which is connected to the first input 15 of the summation unit 16, the second input of which is connected to the output of the generator of the main current pulses 18. The load of block 16 is a hollow lamp, a cathode. Control unit 20 provides synchronization of all device sections. The device works in the following way. The generators 14 and 18 produce current pulses of predetermined amplitude (Fig. 2 a, b), summed by block 16 (Fig. 2 g). The load of the unit 16 is a hollow cathode lamp 19 whose luminous flux is shown in FIG. 2 b. This light flux is converted by the photodetector 1 into a voltage, the form of which is represented in FIG. 2 d. The luminous flux consists of light pulses of amplitude f ppj corresponding to ocHOBHbw current pulses I, and light pulses of amplitude Yion corresponding to additional amplification pulses 1 dop shown in FIG. 2 a ,. at. t decline 1 characterizes the duration of the decline of the light pulse on the proposed, and t decline 2 - by a known method. Unit 2, measuring the voltage at the output of the photodetector 1, generates a signal at the moment when the pulse reaches a voltage pulse proportional to the luminous flux YOCH, which is set to a value, which from output 12 enters input 11 of trigger 10.. additional current pulses, FIG. 2 in. Information on measuring the amplitude of the light pulse 1o (.c also comes from output 3 of block 2 via key 5 to input 13 of block 8, to input 7 of which from the output of block 6 of memory receives a signal characterizing the voltage Uigf, which corresponds to the value of 1d At the moment of equality of the signals at the inputs 7 and 13 of the block -8 of the comparison, it operates and the turn-on signal goes to the input 9 of the trigger 10. The latter is turned on in one state and turns on the generator 14 additional current pulses Fig. 2 c). At the same time, the key 5 is opened, and the key 4 is closed and a signal is received at the input of the memory block 6, the characterizations, the information stored in the block 6 is updated. The cycle then repeats. This current form (Fig. 2g) is derived from. add a rectangular main current pulse to the hollow-cathode lamp and an additional current pulse. To eliminate the loss of speed of the hollow-cathode lamp at the moment of development of the discharge

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the additional current pulse is switched off at the moment when the light pulse reaches a steady-state value (Fig 2 b, c) after all transients in the lamp have been completed. The inclusion of an additional current pulse is also performed after the end of the transition process of the decay of the diminishing light pulse, i.e. when the lamp is deionized to the level corresponding to the additional current pulse. Early switching on of an additional current pulse leads to a higher ionization of the lamp and to an increase in the duration of the decay of the light im663494

pulse, i.e. to the deterioration of its speed.

It has been established experimentally that with a hollow-cathode lamp power supply method, 5 for example, with a duration of main current pulses of 20 µs and an amplitude of 50 mA, the amplitude of additional current pulses of 5 mA leads to an increase in speed of about 1.5 times. This 10 allows you to increase the frequency of the module. light flux tubes with a hollow cathode, to improve the accuracy of determining the area of the absorption pulse during the heat absorption analysis and 15 to increase labor productivity due to a smaller number of measurements.

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Claims (1)

METHOD FOR POWER SUPPLY OF A LAMP WITH A FULL CATHODE, in which the main current pulses are fed to the lamp, as well as an additional current, characterized in that, in order to increase labor productivity in spectral measurements by increasing the speed of the hollow cathode lamp, the additional current is supplied in the form of pulses, at the same time, the luminous flux is measured when it decreases, compared with the luminous flux corresponding to the additional current, the moment of equality of fluxes is recorded and the additional current is turned on, the net flow when it increases', record the moment the flux reaches a steady state and turn off the additional current. SU, „. 1166349 1 1166349 2