SU526854A1 - Time Meter - Google Patents

Description

This allows to reduce the temperature and time errors and increase the noise immunity of the meter. FIG. 1 shows a functional diagram of a time interval meter; in fig. 2 and 3 - time diagrams of his work. The time interval meter contains a generator of 1 exemplary frequency, a vernier generator 2 of shock excitation, circuit 3 matches, triggers 4-7, counters 8, 9, 10 pulses, And 11-19 circuits, control unit 20 and inverter 21. The control unit outputs two The potential signal "O or" 1, depending on which two modes are set in the meter: the operating mode of the meter and the self-contact mode In the measurement mode, the control unit 20 receives the signal "O, IB resulting in the output of the inverter 21, the signal" 1, which opens the scheme “P 15 dl passing and a signal from the output of the coincidence circuit 3 to the trigger input 5. In the initial m state, the circuit "AND 11 is open for access; the signal is 22" Start (Fig. 2), so in this case the signal "1 from the trigger output 4. The circuit "And 12," and the input of which receives the signal 23 "Stop (Fig. 2) in the initial state of the scientific research institute is closed by the signal" O from the output of trigger 7, as a result of which the appearance of the command "Stop before the command" Start . The signal "Start passes through the open circuit" And AND and switches the trigger 5. The output signal 24 (Fig. 2) of the trigger 5 causes the launch of the vernier-south generator of the shock excitation, the output of which appears 25 of the circuit (Fig. 2) with a period repeat tjj. In addition, the Start signal, taken from the output of the And 11 circuit, switches the trigger 4, after which the And 1 circuit is closed. In this case, the meter becomes insensitive to all impulses of interference, which may follow the main signal at the "Start. The electrical signals of the vernier shock excitation generator through the initial “I 18” circuit are fed to the input of counter 8 and the first input of coincidence circuit 3, to the second input of which impulses 26 (Fig. 2) of exemplary frequency generator 1 are received, having a repetition period . When a certain pulse of the vernier generator of shock excitation and the corresponding generator pulse of the sample | Howl frequency is triggered in time. a coincidence circuit 3 and a pulse 27 appears at its output (Fig. 2), causing tripping of the trigger 7. This same pulse passes through the open AND 15 circuit and causes the flip-flop 5 to transfer to its initial state, in which the generator of shock excitation 2 is turned off . The output signals 28, 29 (Fig. 2) of the trigger 7 close the circuit "AND 18 and open the circuits" AND 17, 19. By the time} the fade circuit "And 18 - in the counter 8 accumulate ni imulses of the vernier shock excitation generator. When opening the circuit “AND 19, the pulses of an exemplary frequency generator 1 arrive at the input of the counter 10. The second input signal 23“ Stop (FIG. 2) switches the trigger 5. The output signal of the trigger 5, corresponding to the second input signal, causes the vernier shock generator to restart excitement. The output pulses 25 (Fig. 2) of the vernier shock excitation generator pass through the AND 17 circuit to the input of counter 9 and arrive at the first input of the coincidence circuit 3. When the impulses of the generators 1 and 2 coincide, the coincidence circuit 3 cf. A second signal 27 appears in the output (Fig. 2), which switches the triggers 5, 7 to the initial state. In this case, the vernier generator of shock excitation is switched off, the circuits And 17, 19 are closed, and the flow of pulses to the inputs of all counters is stopped. By the moment of closing the circuits "And 17, 19," d (Fig. 2) of the generator pulses of the exemplary frequency is accumulated in the counter 10, and in the counter 9 - "3 pulses of the vernier shock excitation generator. The measured time interval between the first and second input signals can be provided through time intervals /) 1ism 1+ 2-g, the time segments t, / 2, / 3 can be expressed as follows in terms of the number of pulses L, P2, Pz accumulated in counters 8, 9, 10 and pulse repetition periods and generator exemplary part you this and that: i J «t-j. B) 2 2 - 01 3 3 V Taking into account the principle of operation of the ionic converter, the measured time interval can be represented by the following formula: T, -T, DG; meas i VT s o (n, + n - n,} To + (n, - n,) T. (1) From the above formula, it can be seen that the error of the meter depends on the frequency instability of the vernier generator of shock excitation. The meter is given a self-monitoring mode, in which the overall performance of the meter is checked and the actual frequency of the vernier generator of shock excitation is determined, which makes it possible to find the actual DGD value and take it into account when calculating the measured time interval using the above formula. In the self-control mode, the control unit 20 will issue an “I” signal that opens the “And 14, 16” And closes the “And 15” circuit through the inverter 21. At the same time, the generator pulses of the reference frequency begin to flow through the open “And 16” circuit. 12. Since, in the initial state, the AND 11 scheme is open, the first impulse 30 (Fig. 3) of the exemplary frequency generator, which passed through the AND 16 scheme in the same way as the nerve input signal, passes through the AND 11 and flips trigger 5, zaluskyupny verniero generator of shock excitation. The coincidence circuit 3 is triggered, but the output pulse 27 (FIG. 3) from the co-ownership circuit does not pass to the input of trigger 5, so 1 as the And 14 and 15 circuits are closed. Circuit "AND 15 is closed by the signal" O being removed from the output of inverter 21, and circuit "And 14 is closed by the signal" O being removed from the output of trigger 6. Thus, trigger 5 is not reset to the initial state after the first operation of the coincidence circuit 3, therefore The vernier generator of shock excitation continues to emit PM pulses 25 (Fig. 3) to the input of coincidence circuit 3. When the coincidence circuit is triggered for the first time, 3 pulses from its output flips trigger 7 to the state where the And 17, 12, 13 circuits are opened. When this pulse 26 (Fig. 3) generator exemplary frequency 1, s the next ON time after the coincidence pulse passes through the circuits "And 12 and 13 and flips trigger 6. The signal 31 (Fig. 3) from the output of trigger 6 opens the circuit" AND 14. Since the vernier generator of shock excitation continues to give pulses to the input of the coincidence circuit 3, then after a time interval 4, the coincidence circuit 3 triggers for the second time, signal 27 (Fig. 3) from its output passes through the AND circuit 14 that is open at this moment and flushes trigger 5 to the initial state, after which the vernier shock excitation generator turns off . The plots shown in FIG. 3 indicate that, in counters 10 and 9, there are respectively accumulated nzh generator pulses of the exemplary frequency and "evil pulses of a vernier shock excitation generator, the number of which falls within the interval t. Between two successive output pulses 27 (Fig. 3) of coincidence circuit 3 Taking into account the principle of the vernier converter, it can be seen that the time interval / 4 can be expressed as follows: t shock excitation; nzk, Izl - the number of pulses registered in the counters 10 and 9 in the self-monitoring mode. From the above formula (2), the valid value of the period T of a vernier shock excitation generator can be defined as frtrrl2 7 Б-, - З АТТ-Т Т-тм ГТ. П R, f, L from here / „Зм (П, + П, л,) П + (« з -.) (1, У / .1 h - h т п (+, п), - Пз +) Г “. Thus, the measurement error due to the frequency instability of the vernier shock excitation generator is excluded. Formula and 3 about bp with tp and pmezmer of time intervals, containing a generator of exemplary frequency, the output of which is connected to the first input of the coincidence circuit and through the first circuit And, to the first counter, vernier generator of shock excitation, the output of which is connected P with the second counter, through the third AND circuit with the third counter and through the coincidence circuit with the counting input of the first trigger, the first output of which is connected to the second input of the third AND circuit, and the second output to the second inputs of the first and second AND circuits , at second trigger, the nerve installation input of which is connected to the corresponding inputs of the meter through the fourth and fifth circuit, and the output to the input of the vernier generator of shock excitation and to the third inputs of the second and third circuits And By the fact that, in order to reduce the temperature and time error and increase the noise immunity of the meter, it additionally contains a control unit, two triggers, an inverter and four And schemes, the control unit being connected to the inverter, through the sixth circuit of the second installation at the input of the second trigger and through the seventh circuit “And to the second inputs of the fourth and FIFTH circuits” And whose outputs are connected to the input of the third trigger and through the eighth circuit “And to the input of the fourth trigger, one output of which is connected to the third input of the fifth circuit “And the other output is to the second input of the sixth circuit“ And, the second output of the first trigger is connected to the second input of the eighth and to the fourth input of the fifth circuit “And, the generator output of the reference frequency is connected to the second input of the seventh Scheme“ And, the inverter output is connected to the second install the first input of the second trigger through the ninth And circuit, the second input of iKOTopoft is connected to the IK output of the coincidence circuit and to the third input of the sixth And circuit, the output of the third trigger is connected to the third INPUT of the fourth I. 5 Sources of information taken into account in the examination: 1.Avt. St. No. 303617, G 04F 10/04, 03/20/68. 2. Avt. ABOUT. No. 428353, G 04F 10/04, 01/17/72 (prototype).

-and

- "

m

|

(

CVJ

B