SU401952A1 - DEVICE FOR COMPARING VOLTAGES - Google Patents

Description

one

The invention relates to instrument engineering and to the technique of automatic regulation.

The device is designed to generate at the right time a pulse signal about the sign of the difference of two voltages and can be used in extreme control systems, in which sensors with analogue output are used as sources of monitored signals.

Voltage comparison devices are known, the basis of which is a regenerative comparator. The disadvantages of these devices are that they only signal that a single voltage exceeds a certain threshold value; they do not contain elements that would provide active information about the sign of the difference of the compared stresses at the right time.

The aim of the invention is to obtain, at a time, information in the form of a pulse signal about the sign of the difference of two varying voltages, which allows the device to be used in automatic devices.

To achieve the goal, the output of the excitation generator is connected to the input of the delay unit, the delay time of which is longer than the period of generation of comparator pulses, and to the first installation input of the static

trigger The trigger output is connected to the first inputs of the matching circuits, the second input of one of which is connected to the output of the comparator, and the second input of the other one to the output of the delay unit. The outputs of the coincidence circuits are connected to a different trigger setup.

Thus, information from the output of the device can be automatically used.

on the executive body connected to the output of the device.

The drawing shows a block diagram of the proposed device. The device contains a regenerative comparator 1 with an input 2 for the first compared voltage and an input 3 for the second compared voltage, a static trigger 4 with separate inputs, a matching circuit 5 and 6, a one-shot 7 and a delay block 8.

The scheme works as follows.

If the voltage at input 2 exceeds the voltage at input 3, comparator 1 generates impulses with a period T defined by the parameters of the comparator. If the voltage

input 3 exceeds the voltage of input 2; the comparator does not generate.

If it is necessary to obtain information about the sign of the difference between the compared voltages, a control pulse is fed to the input of the one-vibrator 7. This pulse is simultaneously

starts the delay unit 8, the pulse delay time of which is longer than the period G of the comparator 1 generation, and switches the trigger 4. The sequence sets the enable potential to the first inputs of the matching circuits 5 and 6, thereby preparing them for receiving signals from the comparator 1 and the delay block 8.

If the voltage at input 2 is greater than the voltage at input 3, then information about this comes in the form of pulses to the second input of the matching circuit 5. The first pulse passes through it and returns trigger 4 to the initial state. Thus, at the first inputs of both coincidence circuits, a inhibitory potential is created, which prevents the passage of pulses through them both from comparator 1 and from delay unit 8.

If the voltage at input 2 is less than the voltage at input 3, information about this comes from the output of the coincidence circuit 6 in the form of a pulse, which, after a time longer than the period T of generating comparator 1, comes from delay unit 8. It also returns a trigger 4 initial state.

Thus, if, after starting the device, a pulse is measured at the output of the circuit

coincidence 5, then the voltage at the input 2 of the comparator is greater than the voltage at its input 3. If the pulse is at the output of the circuit of the match 6, then the voltage at the input 3 of the comparator is greater than the voltage at its input 2.

Subject invention

Voltage comparison device comprising a regenerative comparator, excitation generator, static trigger, block

delays and two coincidence circuits, characterized in that, in order to expand the field of application and obtain information about the sign of the difference of the compared voltages, the output of the excitation generator is connected to the input

the delay unit and the first installation input of the static trigger, the output of which is connected to the first inputs of the matching circuits, the second inputs of which are connected respectively to the output of the delay unit and the output of the regenerative comparator, and the outputs to another installation input of the static trigger.