SU966853A2 - Device for determining difference sign of two frequencies - Google Patents

Description

1 The invention relates to radio engineering and can be used to determine the sign of the difference between the near frequencies of two highly stable torus generators. According to the main author. St. No. 801224 discloses a device for determining the difference between two frequencies, comprising two phase detectors, a phase shifter, two short pulse shapers, and a trigger, with the first inputs of the phase detectors. The second input of the first phase detector is directly connected to the first input of the device f, and the second input of the second phase detector is connected to the second input of the device through a phase shifter, two square pulse formers, an inverter and two 2I-2ILI-HE elements, and the output of the first phase detector is the first straight-angle pulse shaper is connected to the short pulse shaper inputs, the output of one of which is connected to the combined first inputs of the 2I-2ILI-NOT elements, and the output of the other to the combined These inputs of these elements, the output of the second shaper - rectangular pulses are connected to the second input of the first element 2И-2ИЛИ-НЕ and to the fourth input of the second element 2И2ИЛИ-НЕ, directly, and to the fourth input of the first element 2И-2ИЛИ-НЕ and to the second input the second element 2I-2ILI-NOT through an inverter, and the outputs of the elements 2I-2ILI-NOT are connected to the installation inputs of the trigger C 1. However, the time of forming information about the sign of the frequency difference in the known device is half the period of the difference frequency. When comparing two precision oscillators that are close in frequency, this time can reach many tens of seconds, which in some cases presents significant inconveniences. The purpose of the invention is to reduce the time of formation of information about the sign of the frequency difference. For this, a device for determining the sign of the difference of two frequencies, containing two phase detectors, a phase shifter, two short pulse pulse bodies and a trigger, with the first inputs of the phase detectors connected to the first input of the mouth (property, the second input of the first phase detector), and the second input of the second the phase detector through the phase shifter is connected to the second input of the device, two shapers of rectangular pulses, an inverter and two elements 2I-2OR-NOT, and the output of the first phase detector through the first A rectangular impulse detector is connected to the inputs of short pulse shapers, the output of one of which is connected to the combined inputs of 25 O

dami elements 2I-2ILI-NOT, and the output of the other - with the combined third. the inputs of these elements, the output of the second driver and rectangular pulses. connected to the second input of the first element 2I-2ILI-NOT and the fourth input of the second element 2I-2ILI-NOT directly, and with the fourth input of the first element 2I-2ILI-NOT and the second input of the second

Leads 2and 2ili-NOT - via an inverter, using the outputs of elements 2I-2, OR-NOT: connected to the setup inputs of the rigger, the third and fourth short pulse actuators, the second inverter and two logical

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an OR expander, with the input of the second inverter connected to the input of the first square pulse generator and the first inputs of the logical OR expanders, the output of the second inverter is connected to the second inputs of the logical extenders according to the OR, the third and fourth inputs of the extenders according to OR are combined and connected respectively to the outputs the third and fourth shapers of short pulses, the inputs of which are combined and connected to the input of the first inverter, while the outputs of the first and second logic expanders. by OR OR ineny to corresponding inputs of the first and second

close to half of the beat period (points B and d), inverters 6, invert these pulses (points D and u), shapers 7,8,12,13 on the front lines of direct and inverted

pulse sequences form short positive pulses (points Ж, 3, И, к). The outputs of the formers 7,8,12, 13 and the inverters 6 and И are connected to the inputs of logical extenders in OR 15 and 16 elements 2И-2ИЛИ-НЕ 9, 10 If at the inputs of element 2И-2ИЛИ-НЕ 10 and the logical expander of OR 16 there occurs a coincidence in time of short pulses with rectangular - on the first pair of inputs from the outputs of the former 7 and the inverter 6, on the second pair from the formers 8 and 5 and the third to the pair from the inverter It and the former 13, on the fourth pair from the former Au 13, the output element 2I-2or NOR 10 has a pulse sequence with a frequency A times the beat frequency which on entry sets flip-flop 11 in a state in which there is a high potential, which through the amplifier display 17 causes illumination of the LED 18.

Claims (1)

At this time, the input of element 2И2ИЛИ-НЕ 9 and the logical expander of OR 15 is received by a pair of positive 4 logical elements 2И-2ИЛИ-НЕ which do not coincide in time, respectively. The drawing shows the structural electrical scheme proposed. devices. The device contains two phase detectors 1 and 2, a phase shifter 3, two shaper k and S rectangular pulses, the first inverter 6, the first and second shaper 7 and 8 short pulses, two element 2I-2ILI-HE 9 and 10, trigger 11, the third and fourth shaper 12 and 13 short pulses, the second inverter, two logical extensions of OR 15 and 16. The device works as follows. At the outputs of phase detectors 1, 2, sinusoidal beats of difference frequency f)% shifted by phase shifter 3 by 90 (points A and B), shapers, 5 of positive half-waves of beats form pulses, the duration of which pulses and at the output of element 2I2IL-HE 9, pulses are missing . If before starting, trigger 11 is in position R, then no more than} / k of the beat period it will switch to position S. When the sign of the frequency difference fj changes, в due to the fact that the sinus function HeMetHan and the cosine function are even, the phase the difference frequency at the output of phase detector 1 will change to 180, and at the output of phase detector 2 will remain unchanged, as a result of which the inputs of element 2I-2IL-NO 9 and logical expander of OR 15 will coincide the pairs of pulses at points E and I, B and K F and D, D and E, at the output of the element 2I-2ILI-NOT 9 by the vehicle The pulses and the trigger T are set to the position R. The high potential from the output of the trigger 11 through the amplifier 19 will cause the LED 20 to illuminate, indicating the opposite sign of the frequency difference. . Thus, the time required to generate information about the sign of the frequency difference is halved compared with the basic invention in connection with the introduction of additional elements, which allowed the relative state of the generators to be twice as often assessed. 3 The invention The device for determining the sign of the difference of two frequencies by aut. St. If 80122, о.т, in order to reduce the time of the AI to generate information about the sign of the frequency difference, it additionally introduces the third and fourth shapers of short pulses, the second inverter and two hygienic OR extenders, and the input of the second inverter is connected to the input the first rectangular pulse generator and with the first inputs of logical OR expanders, the output of the second inverter is connected to the second inputs of logical OR expanders, the third and the third inputs of the extenders are OR connected and connected respectively, with the outputs of the third and fourth shapers of short pulses, the inputs of which are combined and connected to the input of the first inverter, while the outputs of the first and second logical expanders are OR connected to the corresponding inputs of the first and second logical elements 2И-2ИЛИ-НЕ, respectively, Sources of information, those in attendance during the examination 1. USSR Author's Certificate "80122, cl. H 03 O 13/00, 1978.