SU828408A1 - Device for testing threshold elements - Google Patents

Description

one

The invention relates to a pulse technique and can be used to control the parameters of automation devices and telemechanics, in which it is necessary to measure the response voltage and release of threshold elements and their hysteresis.

A device for voltage monitoring is known, which contains several sources of stable voltage, sawtooth generators, reference frequency generators, meters with digital indication, zero-organs, and controls 1.

The disadvantages of the known device when it is used to measure the voltage of the response and hysteresis of the threshold elements include the inability to control without the use of additional devices (variable voltage source) and manual operations, the impossibility of simultaneous (periodically repeating) measurement and digitizing the voltage actuation and hysteresis of the threshold elements.

A device containing a controlled threshold element, a sawtooth generator (integrator), sources of positive and negative stable voltages, two counters is known.

two display units, a pulse generator, analog keys, a logic unit, the inputs of which are connected to the output of the pulse generator and outputs of the monitored threshold element, the outputs of the logic unit are connected to the first inputs of analog keys and to the inputs of counters, the outputs of which are connected to the inputs of display units, the second inputs analog keys

connected to the sources of positive and negative stable voltages, the outputs of the analog switches are connected to the input of the sawtooth generator, the output of which is connected to the input

controlled threshold element 2. A disadvantage of the known device is that it cannot periodically measure the threshold and hysteresis of the monitored threshold element.

The purpose of the invention is to provide a periodic measurement of the trigger threshold and hysteresis. To achieve this goal in

a device for monitoring threshold elements, comprising a controlled threshold element, a sawtooth generator, sources of positive and negative stable voltages, two

counter, two display units, generator

Pulses and two analog switches, the output of the sawtooth generator is connected to the input of the controlled threshold element, the outputs of the first and second counters are connected respectively to the inputs of the first and second display units, the first inputs of the first and second analog switches are connected respectively to the outputs of the sources of positive and negative stable voltages the outputs of the analog switches are connected to the first input of the sawtooth generator, three formers and two elements And, the first input which are connected to the output of the pulse generator, the second input of the first element I is connected to the second input of the first analog switch, to the inverse output of the monitored threshold element and to the input of the first driver, the output of which is connected to the third inverting input of the first element I, to the second input of the sawtooth generator and with the input of the second shaper, the output of which is connected to the reset input of the first counter, the counting input of which is connected to the output of the first element And, the second input of the second element And with of the connections to the second input of the second analog switch, a direct output of the controlled threshold element and to the input of the third shaper whose output is connected to the reset input of the second counter, the counting input of which is connected to the output of the second member I.

FIG. 1 shows a diagram of the proposed device; in fig. 2 - diagrams of the device voltage.

The device contains: 1 and 2, respectively, the inverse and direct outputs of the controlled threshold element, 3 and 4, respectively, the sources of positive and negative stable voltages,

5- controlled threshold element

6 is an analog key, 7 is a saw-tooth voltage generator, 8 is a driver, 9 is a counter, 10 is an And element, 11 is a pulse generator, 12 is a display unit, 13 is a driver, 14 is an analog key, 15 is a driver, 16 is element I, 17 - counter, 18 - display unit.

The inverse output 1 (Fig. 1) of the controlled threshold element 5 is connected to the first inputs of the analog switch 6, element 10 and the input of the driver 8, the output of which is connected to the second inverting input of the element 10, to the first input of the sawtooth generator 7 and driver 13, the output of which is connected to the reset input of the counter 9, the outputs of which are connected to the inputs of the display unit 12, the second input of the generator 7 is connected to the outputs of the analog switches 6 and 14, the first input of the last of which is connected to the direct output 2 of the counter iruemogo threshold element 5, with

the first input element And 16 and with the input of the imaging unit 15, the output of which is connected to the reset input of the counter 17, the outputs of which are connected to the inputs of the indicator unit 18, the output of the generator 11 pulses connected to the third inputs of the elements 10 and 16, the outputs of which are connected respectively to the counting inputs counters 9 and 17, the output of the generator 7 is connected to the input of the controlled threshold element 5, the outputs of the sources of positive 3 and negative 4 stable voltages are connected respectively to the second inputs of analog switches 6 and 14.

FIG. 2: 19, 20, 21, 22 — voltage plots, respectively, at the inverse output 1, at the output of the driver 8, at the direct output 2 and at the output of the sawtooth generator 7.

The device works as follows. The controlled threshold element 5 and the device are energized. The pulses of the generator 11 begin to flow on the elements And 10 and 16. At the moment

time Tj (plot 19 of Fig. 2) from the inverse output 1, the signal "1, which goes to key 6, to one of the inputs of the element 10, is applied, allowing it through this input, and to the driver 8. This driver

generates a pulse (plot 20, fig. 2), which sets the sawtooth voltage generator 7 to the initial state and starts the imaging unit 13, which, on the reset input, resets to "0 counter 9,

which determines the threshold.

Upon termination of the pulse from the imaging unit 8 (time point TZ, plots 20, 22 of Fig. 2), the resolution to the third, inverse input of element 10 is received. As a result, the two control inputs of element 10 become open, and the reference frequency pulses from the generator 11 begin to arrive at the counter 9 of the threshold. At the same time, the generator

7, the saw-tooth voltage begins to form an incremental section of the saw-tooth voltage by passing a positive voltage from the source 3 through the key 6, which is fed to the input of the threshold element 5 (plot 22 of FIG. 2). On the display unit 12, the information accumulated in the counter 9 is displayed.

When the saw-tooth voltage reaches the threshold of the threshold element 5 f / cp / TZ (plot 22 of Fig. 2), the latter is triggered, with the result that the "1" signal appears at its direct output and the signal "O that closes key 6, stopping the flow of voltage from source 3 to the working input of generator 7. Counter 9 will be filled with the number of pulses corresponding to the threshold of the threshold element with indication on unit 12.

The signal "1 from the direct output of the threshold element 5 arriving at the key 14 opens it, and the generator 7 receives a stable voltage from the negative voltage source 4, due to which the generator 7 begins to form the feed section of the sawtooth voltage (plot 22 of FIG. 2). At the same time, "1 from output 2 is fed to the reset driver 15 and to the element I 16. The reset driver 15 generates a pulse that sets the hysteresis counter 17 to the zero state on the reset input. Element I 16 permits the passage of pulses from generator 11 to counter 17. At time T, when the voltage at the output of generator 7 drops to a level corresponding to the release voltage of the threshold element {f / shch plot 22 of FIG. 2), the latter releases, as a result of which, at the output of the threshold element 1, the signal "1 appears, and at the output 2 -" O. The key 14 and the AND element 16 are closed, as a result of which the negative polarity voltage is released, the flow of the reference frequency from the generator 11 to the hysteresis counter 17 is stopped. In the latter, the number of pulses corresponding to the hysteresis of the threshold device is recorded. This number is displayed by block 18.

At time 4, the occurrence of the signal "1 at the inverse output of the threshold element 5 leads to a repetition of the state of the device corresponding to the state at the time TI, after which the repeated switching cycle begins, as described above.

The use of the proposed device allows the automatic, periodically repeated monitoring of the threshold and the hysteresis of threshold devices. In this case, it is possible to significantly simplify the setting of the PU, due to the periodicity and simultaneity of the measurement; it becomes possible to more accurately analyze the threshold elements during the development and at the operation stage, as a result of which the reliability of the experimental data increases.

Claims (2)

1.Ornatsky P.P. Automatic measurements and devices. Kiev, Naukova Dumka, p. 142 2. Malinovsky VN Digital voltmeters of integrating type. Sat Devices and control systems, No. 2, 1973, p. And -12, fig. 4 (prototype).