SU363989A1 - DEVICE FOR CONSTRUCTION IN SQUARES OF ELECTRICAL SIGNALS - Google Patents

Description

one

The invention relates to the field of measurement and computing.

Known squareing devices are based on the use of nonlinear elements, such as thermocouples, semiconductor and vacuum devices, diode devices, KCHMflTOpOB, etc.

However, all of them allow to obtain an output signal in the form of a DC voltage and, in order to obtain corresponding digital samples, always require the use of additional nodes — analog-to-code converters.

The purpose of the invention is to obtain periodic digital samples proportional to the square of a slowly varying current (or voltage).

This is achieved by the fact that the device contains a triggered frequency divider connected in series, a duration standardizer and a waiting shock excitation generator, the first and second outputs of which are connected to a different diagonal of the bridge circuit via an appropriate capacitor, and the trigger frequency divider is connected to the output e. controlled frequency and third valve.

The drawing shows a block diagram of the proposed device.

The original signal is in the form of a constant / o or slow varying current (for example, w) ly. (T) kK (i) through an input reed-reed switch / is applied to a temperature-sensitive resistor 2 with resistance included in one of the arms of the equal-arm bridge 3. Resistance the bridge arms are chosen equal to the resistance of the thermistor at the operating point. When the circuit is turned on, the resistance RQ is significantly higher than its operating value, and the bridge is unbalanced. The unbalance voltage is increased by the amplifier 4, detected by the phase detector 5, and is applied to control the frequency of the pulses of the generator 6 of the controlled frequency.

The frequency FI of the generator pulses 6 is divided by a time using the trigger divider frequency 7. Received impulses with frequency

Fl, after the standardizer 8, their duration is controlled by a waiting generator 9 of shock excitation, which provides a continuous sequence of radio pulses following the frequency Fl with a duration t

and the frequency of filling F (, -, Pulses

TO

through 10 vt capacitors. 11 are fed to the diagonal of the power supply of the bridge circuit, thereby closing the feedback circuit. Due to the presence of this feedback, under the influence of the power supplied to the bridge circuit, the thermistor is heated, therefore, its resistance may decrease, leading to corresponding changes in the voltage unbalance and frequency of the generator 6.

The phase detector is controlled by an RF voltage from the output of the shock excitation generator, which arrives at the second input of the detector through the auxiliary emitter follower 12 and the phase-correction unit 13, which compensates for phase shifts in the LIE1II bridge detector. After the end of the transient process (in steady state), the resistance of the thermistor takes on a value, the closer to the value of b, the higher the gain of the circuit. In this case, the set value of the frequency of the generator 6 can be associated with the value and power PO of the electrical oscillations supplied to the thermistor by feeding it with radio pulses, in the following form

b. 51

R. about

where t is the period of the following radio pulses.

In this steady state, the circuit is not measured, after it has been properly heated. The measurement process starts at the moment / in time of pressing the button 14, transferring the starting trigger 15 to the second steady state. At that, the valve 16 is opened and short clock pulses from the generator 17 begin to flow to the counting inputs of the trigger 18. The first clock pulse transfers the trigger 18 to the second steady state, in which the pulse-potential valve is open and the pulses from the generator 6 output with the frequency the summing input of the reversible counter 19. The second clock pulse returns the trigger 18 to its initial state by closing the valve 20 and the transfer of the trigger 21 to the second steady state. Thus, to the summing input of the reversible counter 22 for the time T from the output of the generator 6, pulses are fed, the number of which is equal to

 2PRO

c-lT- - f T

L,

. -one .

f .z Art

The voltage drop taken from the unit output of the trigger 21 closes the reed switch I, which supplies the test current lx (t) to the thermistor 2. Under the influence of the added power determined by the value fx (t), the circuit goes out of the initial steady state and after some The time Tper comes to a new steady state at a new value of the pulse repetition frequency of the generator 6. With the new steady state of the circuit, the equality should be

. +,.,

2/2

where is the period of repetition of the power supply pulses of the bridge circuit after nodachi to the thermistor of the converted current. Since the third clock pulse again triggers the trigger 18 to the second state, without changing the state of the trigger 21, the valve opens and the pulses of the generator 6 begin to flow to the subtracting input of the reversible counter during time T, i.e. before the fourth clock pulse arrives.

During the time T, the pulses passing with the frequency FZ, the number of which is equal to

N, T. A.

After the arrival of the fourth clock pulse, the entire circuit returns to the initial state with a short pulse, obtained by means of the shaping circuit 23 from the voltage drop from the single output of the trigger 21, and the number N in the reversing counter is equal to

2n

Nt

J - Kl .. ,,

2 7 where / (

 constant coefficient. /"AND

The same impulse, but delayed on Afi by section a - b of delay line 24, ensures the transfer of the counting result to external circuits (digital display, universal computer, etc.), and additionally delayed by section b - by the value used for resetting reverse counter, preparing it to recalculate the pulses of the next cycle T. At the same time, this pulse through diode 25 transfers trigger 18 to the second state, starting a new measurement cycle.

Subject invention

A device for squaring electrical signals containing a resistive

a bridge circuit, one of the diagonals of which through an amplifier is connected to a phase detector, the output of which is connected to a controlled frequency generator connected via the first gate to a reversible counter,

connected in series emitter innovator and phase-correcting unit connected to the phase detector, generator connected through the second valve to the first trigger connected in series with the second trigger, the outputs of which are connected to the reversible counter through the first and three IED valves and forming circuit connected through the line delays with a trigger trigger whose output is connected

to the second valve, and the input forming

The circuit is connected to the first valve and to the input switch, characterized in that, in order to improve the accuracy of the device and increase the sensitivity, it contains a series-connected trigger frequency divider, a standardizer of duration and waiting, the first and second outputs of the shock excitation generator the capacitor is connected to another diagonal of the bridge circuit, and the input of the trigger frequency divider is connected to the output of the controlled frequency generator and the third valve.

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