SU1265633A1 - Voltage ratio meter - Google Patents

Abstract

The invention is intended to measure the instantaneous values of variable phase-matching voltages. The purpose of the invention is to increase the reliability of the meter by simplifying the device. The meter contains a voltage-to-frequency converter 1, a reversing attenuator 3, a differential amplifier 4, a voltage modulator driver 5 and a threshold device 7. To achieve this goal, a multiplying device 6 connected to the circuit elements is introduced into device 1. 2 Il. / k / VA f

Description

one

The invention relates to electrical measuring equipment and is intended to measure the instantaneous values of variable phase-matching voltages.

The purpose of the invention is to increase the reliability of the meter by simplifying the device.

FIG. 1 shows the block diagram of the meter in FIG. 2 time diagrams for his work.

The meter contains a voltage-to-frequency converter 1, the output of which is connected to the counting input of the reversible counter 2, a digital controlled attenuator 3, the signal input of which is connected to the second input terminal of the meter, and the control inputs of the counter 2, differential; real amplifier 4, first and

The second inputs of which are connected to the first input meter i and the attenuator 3 output, respectively, the shaper 5 of the voltage module, the input of which is connected to the output of the amplifier 4, and the output - to the input of the voltage frequency converter 1, the multiplier 6, the first and second inputs are connected. respectively, with the first input and output of the amplifier 4, and the threshold device 7, the input of which is connected to the output of multiplier 6, and the output to the control input of the reversible counter 2.

The meter works as follows.

When entering the first and second inputs of the voltage meter and, (t) A, smcot (Fig. 2a) and) .5 AjSincot (Fig. 2b), where A and A are the amplitudes of the voltages on the first and second

U / (t) Bri U (t), i.e. at jU, (t) | .i | U, (t) lj

where E is the voltage constant

level

The voltage Uy (t) determines the direction of the change in the state of the reversible counter 2, the input of which receives pulses from the converter 1, which forms a sequence of pulses with a frequency F equal to

,; (t) (Fig. 2d),

265633

the inputs of the meter, respectively, CO, are the circular frequency of the measured signals, 5t is the current time,

At the output of the attenuator 3, a signal U, (t) is formed, equal to

, 0 U, (t) K (t) U (t) (ti,) sincOt,

where t is the initial moment of the measurement interval}

5 Kg (t) is the attenuation coefficient of the attenuator 3 at time tg,

at the input of amplifier 4, the signal U (t) is proportional to the difference between the signals 20) and (t)

U4 (t), (t) -U, (t) (figv), where k is the proportionality coefficient,

and the output of the imaging unit 5 is the signal U5 (t), equal to the modulus of the signal U4 (t)

U5 (t) | U4 (t) | (Fig. 2d). At the output of multiplier 6, a signal Ug (t) is formed, proportional to the product of the signals U, (t) and y, (t), and the polarity of the signal U (t) is positive if the signals U, (t) and U (t a) coincide in phase, which is the case when the implementation of service is carried out.

ju, (t), (t) l

and negative if the phases of the signals U, (t) and Uj (t) are opposite, that 40 takes place when the condition

lu, (t) 14u, (t) l.

At the output of the threshold device 7, a voltage U7 (t) is formed, determined by the equality

Oh i with lU, (t), (t) l

where S is the slope of voltage to frequency conversion.

The reversible counter does not work with addition at U7 (t) E and for subtraction at U (t) 0.

When) l-c | U, (t) l, the reversible counter 2 works on addition, and with it the attenuation introduced by attenuator 3 increases, as a result, the signal Uj (t) decreases

Claims (1)

Claim A voltage ratio meter containing a series-connected differential amplifier, a voltage module driver, a voltage-to-frequency converter, and a control unit in the form of a reversible counter bitwise connected to the control inputs of the digital attenuator, the signal input of which is connected to the meter input terminals, respectively, and the output is to the second input of the differential amplifier, as well as a threshold device, which is different from the fact that In order to increase reliability, a multiplying device is introduced into the meter, the inputs of which are connected to the first input of the meter and the output of the differential / amplifier, and the output is connected to a threshold device connected to the control input of the reversible counter.