SU1451610A1 - Converter of minimum value of pulsed voltage to d.c. voltage - Google Patents

Abstract

The invention relates to electrical measuring equipment and serves to simplify the device and increase the reliability of its operation. The converter contains a comparator 1, an integrator, which includes an operational amplifier 2, a time specifying a capacitor 3 and a time — a master resistor 4, and a source 5 of the reference voltage. Introduction of key 6 allows automatic conversion of the minimum pulsating voltage into a constant voltage with a significantly smaller number of elements. 2 Il. (L ate Ш1, / a

Description

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The invention relates to electrical measuring technology and can be used to measure the minimum value of a pulsating unipolar voltage.

The purpose of the invention is to simplify the device and improve its reliability by reducing the number of elements.

Figure 1 shows the functionality of the converter circuit; 2, diagrams showing his work.

The converter contains (FIG. 1) a comparator 1, an integrator consisting of an operational amplifier 2, a time - master capacitor 3 and a time of the supply resistor 4, a source 5 of the reference voltage and a switch 6, One input of the comparator 1 is connected to the input of the converter, the output of the operational amplifier 2 is connected to one pin of the time of the driving capacitor 3 and another input of the comparator 1, and the other pin of the time of the driving capacitor 3 is connected to the inverting input of the one of the amplifier 2, which is connected to the source 5 PORN voltage. The control input of the switch b is connected to the output of the comparator 1, the output terminals of the switch b are connected to the terminals of the time of the driving capacitor 3, and the output of the operational amplifier 2 is connected to the output of the converter,

The converter works as follows.

Initially, the time setting capacitor 3 of the integrator is in a discharged state, and the output voltage of the converter is zero. When the pulse voltage is applied to the input of the converter (FIG. 2a), the comparator 1 outputs a locking key 6 (FIG. 2B). In this case, the voltage rise on the output of the integrator due to the charging time of the driving capacitor 3 by the current generated by the resistor 4 from the voltage of the source 5 of the reference voltage starts. The voltage rise will continue until it exceeds the voltage value At the input of the converter at any arbitrary moment of time (FIG. 2c), the comparator 1 switches, and at its output a control signal appears that closes the switch 6, the trepes which quickly discharge the time of the setting capacitor 3, that

leads to a decrease in voltage

and

ayu

output converter. With

In this case, this process occurs quickly due to low key resistance 6, At the moment when the voltage Uahu on the output of the converter becomes less than the minimum value and d, "c input voltage, the comparator 1 switched again and the prohibition of the key 6, which again will result to increase the voltage U c, at the output of the converter until it reaches the minimum value of the input voltage, which will result in the next switching of the comparator 1 and the closure of the switch 6. At the same time, during the minimum of the input voltage, the output voltage and g ,,,. The converter will oscillate around this value, and the frequency of these oscillations will be determined by the time delay of the discharge of capacitor 3 through switch 6 and the inertia of operational amplifier 2. When the input voltage increases, it will exceed the steady-state value of voltage Ugj at the output of the converter.

The described process will be repeated and the steady-state voltage at the output of the converter will be equal to the minimum value of the pulsing constant voltage at its input. The absolute conversion error will then be determined from the following expression

and

min

 Uo - -RC-

Ujj is the voltage value at the output of the source 5 reference

.approach;

R - time resistance -

driver resistor 4;

C - capacity time setting

capacitor 3; - the duration of the pulsating voltage exceeding its minimum value.

In the limiting case, t- T, where is the period of the input signal. Accordingly, time t. output (Fig, 2)

Chy. RC

and

Thus, the proposed converter allows automatically.

145

convert the minimum pulsating voltage into a constant voltage with a significantly smaller number of elements, which simplifies its design and increases its reliability.

Claims (1)

Invention Formula The minimum ripple voltage to constant voltage converter containing a comparator, the first input of which is connected to the converter input, the integrator, the time of the driving capacitor connected between the output of the operational amplifier and its inverting input, in the form of an operational amplifier, is one the output of which is connected to the inverting input of the operational amplifier, the other is connected to the reference voltage source, and the output of the operational amplifier is connected to the first input of the comparator and the output In order to simplify and increase reliability, it additionally includes a key, the control input of which is connected to the comparator output, and its output terminals are connected to the terminals of the master capacitor. Ч1Л41-Л-ПЛ Вш / 77 / mtn sri.2