SU1557530A1 - Apparatus for stroboscopic scanning - Google Patents

Abstract

The invention relates to a measurement technique and can be used in stroboscopic oscilloscopes. The purpose of the invention is to simplify the device stroboscopic sweep. The device has two modes: "setting" and "work". In the "tuning" mode, meter 8 measures samples of a fast sawtooth voltage generator 1, which are stored in memory block 7. In the "operation" mode from memory block 7, through a digital-to-analog converter 12, the comparator 4 receives a slow sawtooth voltage, which in form coincides with the fast sawtooth voltage of generator 1 (differing only in the time scale). A fast sawtooth voltage from generator 1 is fed to comparator 4 through switch 2. At the time of comparing both sawtooth voltages, a gate pulse is generated at the output. Since the shapes of the sawtooth stresses are the same (the same nonlinearity), the strobe pulses follow with a stable repetition rate. 4 il.

Description

The invention relates to measuring equipment and can be used in stroboscopic oscilloscopes and meters.

The purpose of the invention is the simplification of the device stroboscopic scan,

In FIG. 1 shows a structural diagram of a device; figure 2-ί- timing diagrams of the operation of the device.

The device comprises a fast sawtooth voltage generator (GBPN) 1, switch 2, synchronization unit 3, comparator 4, element 2 OR 5, 6 pulse counter, memory unit 7, meter 8, 9 pulse generator, first 10 and second 11 delay units, digital-to-analog Converter 12 (DAC).

The GBPN output is connected to the first input of the switch 2, and the GBPN input is connected to the output of the synchronization unit 3, the input of which is connected to the first output of the switch 2, the second input of which is connected to the synchronization signal bus, and the second output is connected to the first input of the comparator 4, the output of which >. connected to the output bus and the first input of element 2 OR 5, the output of which is connected to the input of the pulse counter 6, the output of which is connected to the first input of the memory unit 7, the second input of which is connected to the output of the meter 8, the first input of which is connected to the third output of the switch 2, the third the input of which is connected to the output of the pulse generator 9, and the fourth output is connected to the input of the first delay unit 10 and to the input of the second delay unit 11, the output of which is connected to the second input of the meter 8. The output of the first delay unit 10 is connected to the second electronic input ment 2or 5 minutes the third input of the storage unit 7, whose output is connected to the input of DAC 12 whose output is connected to a second input of comparator 4.

The device operates as follows.

In Setup mode, switch 2 connects the output of the 9 pulse generator to the input of synchronization block 3, the inputs of the first 10 and second 1! delay units, and the output of the generator 1 fast sawtooth voltage to the first input of the meter .8 "In this mode, at η points of sawtooth voltage U„ GBPN 1 measured and entered into the memory unit 7 code words Υ · _χ 1 = 1,

2 .., n, determining the amplitude of the sawtooth voltage at a given point. On the positive edge of the pulses (FIGS. 4, U1) of the pulse generator 9, the synchronization unit 3 generates a positive pulse (U2), the negative edge of which triggers GBPN 1 (U3). This voltage is supplied to the first input of the meter 8. After a while from the moment of formation of the positive edge of the pulse of the generator 9 pulses at the output of the second block. 11 delays generated positive. pulse triggering the meter. 8, the output of which is formed by the digital equivalent of Y ₁ (Fig. 2), corresponding to the voltage value of GPBN 1 U _{n (} at the first point. The time value ^ 2. Is determined by the delay value of synchronization unit 3 and GPBN 1, Codeword U ₍ received at the second input of the memory unit 7. It is stored in the memory by a negative pulse from the output of the first delay unit 10. U5 This pulse is generated after time with respect to the moment of formation of the positive edge of the pulse of the pulse generator 9. The value of определяется is determined by the duration of the meter 8. At the first input of the memory unit 7 from the output of the counter 6 pulses receives a code word that determines the address of the memory cell.

Thus, in the first cell of block-7 of the memory, the code word Y < _? determining the amplitude of the sawtooth voltage at the first point. On the positive edge of the negative pulse from the output of the first delay unit 10, the state of the pulse counter 6 is increased by one, and a code word corresponding to the second memory cell is set at the first input of the memory unit 7. On the positive front of the second pulse of the 9 pulse generator, GPBN 1 is started again, the code words Υ ^, which determine the amplitude of the sawtooth voltage at the second point, are measured and then entered into the memory unit 7. In this way, they are computed. are stored in block 7 of the memory η code words that determine the amplitude of the sawtooth voltage of the fast sawtooth voltage generator 1 at η points. In the Operation mode, the switch 2 connects the input of the synchronization block 3 to the synchronization signal bus, and the output of ГПБН 1 to the first input of the comparator 4. In this mode the first 10 and second 11 delay units and the meter are not used, the synchronization signal is fed to the input of the synchronization unit 3, which generates start pulses GPBN 1. The sawtooth voltage U _{n is} supplied to the first input of the comparator 4 (Fig. 3), at the second input of which a constant voltage U _C1 = U _K is installed, where _{k <} is the sawtooth voltage amplitude at a given point corresponding to the code word Y |, Voltage U is generated by a digital-to-analog converter 12, At the time of comparing the sawtooth voltage U _n U _c with a constant voltage generated strobe U2 (fig.Z) whose position is shifted in time from the comparison voltage output from the GCAP 1 with a linearly increasing step · comparing the voltage U _o at the intersection point of this voltage with a reference sawtooth voltage zheniem y = kt. This compensates for the time 'ξ, arising as a result of the non-linearity of the voltage at the output of GPBN 1, when comparing with the linearly increasing step of the comparison voltage P _о , shifting the strobe pulse along the time axis, the strobe pulse entering the counter input 6 pulses increases state per unit. As a result, at the output of the digital-to-analog converter 12, a constant voltage equal to U _Xi corresponding to the codeword Y ^ is generated.

Each of the η voltage levels of the digital-to-analog converter 12 corresponds to a codeword written in the memory unit 7 that determines the magnitude of the comparison voltage, taking into account the voltage generation law of GPBN 1, thereby compensating for the non-linearity of the voltage of the latter.

The device provides linearity of the strobe scan, correcting the nonlinearity of the fast sawtooth voltage. Code words that determine the magnitude of the comparison voltage are calculated digitally. method with high accuracy.

Claims (1)

Claim 15 A stroboscopic scan device containing a fast sawtooth voltage generator, the output of which is connected to the first input of the switch, and the input to the output of the unit 20 synchronization, the input of which is connected to the first output of the switch, • the second input of which is connected to the bus of the synchronization signal, and the second output is connected to the first input of the comparator, 25 output of which is connected to the output bus and the first input of the 2 OR element, the output of which is connected. to the input of the pulse counter, the output of which is connected to the first input of the memory unit, the output of which is connected to the input of the digital-to-analog converter, and the third input - to the second input of the 2OR element and the output of the first delay unit, the input of which is connected to the input of the second delay unit and. the fourth input of the switch, the third input of which is connected to the output of the pulse generator, and the third output with the first input of the meter, the second input of which is connected to the output of the second delay unit, characterized in that, in order to simplify the device, the input of the meter is connected to the second input of the memory unit, and the output of the digital-to-analog converter - to the second input of the comparator,