SU789865A1 - Threshold recorder - Google Patents

Description

(54) THRESHOLD RECORDER

one

The invention relates to electrical measuring equipment and can be applied in threshold automation devices, in analog radioisotope relay devices, in conversion units designed for tolerance control of the pulse frequency.

Known threshold recorders are responsive to the frequency of the input signal. Nala Such devices contain input pulse formers, an integrator and a threshold device to the output of which the recorder 15 is connected.

one.

The disadvantage of such devices is a significant area of uncertainty, the cause of which is the presence of a ripple voltage at the output of the integrator.

It is also known a device containing serially connected pulse normalizer, integrator threshold device 2.

The disadvantage of this device is low resolution. In this system, the voltage is on the integrator and the INT (MOA). where f TH, SOA - the frequency of the pulses fed to the input di

the registrar. Depending on this voltage, the threshold device assumes a zero or one state. The transition of the recorder to the zero state corresponds to the frequency of the pulses at its input f., And the transition to the single state corresponds to f,. The resolution of the threshold recorder is determined by the difference in frequency corresponding to the trigger threshold and the release threshold. f f 4 - i.,. To increase the resolution of the recorder, it is necessary to maximally approximate the values of the frequencies {d and. This convergence is limited by voltage fluctuations on the integrator. For normal operation of the registrar, the inequality must

4 (, (1)

where A is the amplitude of the ripple voltage across the integrator. If this inequality is violated for some values of 5 V, there is an uncertain state of the recorder. In this state, with an unchanged input signal, it continuously transitions from the zero state to the single state and back to the frequency of the input signal.

The purpose of the invention is to increase the resolution of the threshold recorder.

The goal is achieved by the fact that the threshold registrar containing serially connected pulse normalizer, integrator and threshold device is equipped with t) -trigger 3) whose input is connected to the output

the threshold device, -C-input is connected to the input of the pulse normalizer and the trigger outputs serve as outputs of the recorder,

FIG. 1 shows a block diagram of the recorder; in fig. 2 - the cyclogram of his work.

The device contains pulse normalizer 1, integrator 2, threshold device 3 and D-flip-flop 4, B-input of which is connected to the output of the threshold device, and C input is connected to the input of the pulse normalizer, while the trigger outputs are recorder outputs.

The device works as follows.

A sequence of pulses comes from the frequencies and t at the input of the pulse normalizer, and is generated at the integrator. voltage (depending on this voltage, the threshold device assumes a zero or one state. In case 2, the state of the trigger repeats the state of the threshold device. In the case of fa and inequality (1), the state of the threshold device and the trigger can be different. This is because the state of the threshold device can change at any time, and the state of the trigger only at the moment of arrival of the input pulse. It does not apply to a certain amplitude value of the ripple voltage on the integrator and the inequality constraints (1) do not apply to the proposed recorder.

The time diagrams of the voltage on the recorder shown in FIG. 2 correspond to the case when fj fi i and (f) (Fig. 2 a shows a sequence of pulses input to the recorder; Fig. 2 b shows the change in voltage on the integrator Fig. 2 c shows the change in the state of the threshold device: Fig. 2). 2 - change of the state of the recorder in time).

Up to time point -t, the voltage on the integrator is less (j. At time point -fe, the frequency of the input pulses doubles. This change in the frequency of the input pulses causes a corresponding voltage change on the integrator. At time i / i, the voltage on the integrator

reaches value - U

what causes

transition threshold device in the unit state. Since f - f - f and the inequality condition (l) is violated /, until the next pulse arrives, the voltage across the integrator falls below U and the threshold device returns a zero state. In the time interval from .to -t, the threshold device is in an unstable state and generates pulses at the frequency of the input signal. At the same time, the trigger retains the zero state, because at the moment of arrival of the pulse to the input of the {{1} scorter, the threshold device is in the zero state. At the moment of time, the frequency of the input signal is doubled, and the first impulse that arrives after this (the moment -t) places the trigger in one state. At time point -tg, the frequency of the input pulses is halved. At the time point -If, the voltage across the integrator reaches the value O and translates the horn device to the zero state. - The first pulse that arrives after this returns the trigger to the zero state. In the time interval from -b (, to -b7 the threshold device is in an unstable state, and the trigger stores the zero state similarly to the time interval. At the time -t - the frequency of the input pulses is halved, the voltage across the integrator decreases and the threshold device maintains the zero state, and the trigger is in the same state.

As can be seen from the principle of operation of the device, the amplitude of the ripple voltage across the integrator does not affect the resolution of the proposed recorder. The degree of resolution of the resolution is determined by the amplitude of the ripple voltage at the integrator, due to the discreteness of the input signal of the threshold recorder, which depends on the time constant and of the integrator C. When the product of T f is changed from up to 100, the voltage ripples on the integrator change from 18 to 1% of the constant voltage component. The resolution of the threshold recorder is increased by the same amount. At the same time, it is positive that with increasing recorder speed (decreasing), the gain in resolution when using the proposed recorder as compared to the known one increases.

The proposed technical solution / allows to improve the existing and commercially available analogue radioisotope relay devices.

Claims (2)

1. US Patent 3584298, 324-78, 1969. 2. USSR Author's Certificate No. 235105, cl. G 05 B 1/02, 1968.