SU437972A1 - Apparatus for producing sawtooth voltage - Google Patents

Description

(54) DEVICE FOR RECEPTION

VOLTAGE

The invention relates to the field of electrical measuring equipment and can be used to determine the phase shift of periodic signals ranging from 0 to 360 ° over a wide range.

A device for generating a sawtooth voltage is known, comprising a pulse shaper, a key, a function generator, a memory device, an adder, and a direct current generator, which, in combination with a storage capacitor, forms a saw voltage generator.

The proposed device differs from the known one in that it has a switch, a comparator and an inverter, the input of the device through a pulse shaper connected to a switch, keys and through a function generator with an adder, the second input of which is connected to the output of a sawtooth generator, the output of which connected to the "switch. The output of the adder through the key is connected to a storage device, which is directly and through the inverter connected to the switch.

This makes it possible to increase the accuracy and broaden the frequency range of the device.

FIG. 1 shows a block diagram of an apparatus for producing a sawtooth voltage; in fig. Figure 2 shows the timing diagrams of the operation of the circuit for a shift of 90 °.

In the proposed device, the input X is connected via a driver G. The pulses are connected to the first control input of switch 2, to the function generator 3 and to the -4 key.

The switch output is connected via a sawtooth generator 5 through a comparator 6 to the second control input of the switch and directly to one input of the adder 7, to the other input of which the function generator 3 is connected. The output of the adder 7 is connected to the storage device 8 through the key 4 nb mediatedly, as well as through the inverter 9 is connected to the inputs of the switch 2.

The input periodic voltage (/ in is converted by the pulse shaper into pulses corresponding to the beginning of the periods of the input signal. These pulses control

operation of the switch, connected to the saw-tooth voltage generator terminal a. At the same time, the f / g voltage is supplied to the INPUT of the sawtooth voltage generator directly from the output of the memory device 8, the amplitude of which is proportional to the duration of the previous input voltage period. At the output of the sawtooth generator, an increasing one appears (Voltage U5 KfJ8-t, where K is the coefficient

Transmission of sawtooth voltage.

When the voltage U reaches the trigger level of the comparator, it triggers and, via a switch, connects the negative voltage from the inverter output to the input of the sawtooth generator. The voltage at the output of the sawtooth generator begins to decrease, reaching zero by the end of the period.

In addition, the pulses from the output of the pulse former are fed to the functional generator 3, the output voltage (Uj of which in each period T 1 // in varies according to the law,

Mr IJ

-s - -t

where t / o and L are equal coefficients.

The output voltages t / i and u of the function generator and sawtooth voltage generator are fed to an adder. Upon arrival of pulses from the pulse driver, key 4 is opened, and the output voltage of the adder 7 is compared with the voltage that was fixed by the memory 8 at the end of the previous period Tn. If the frequency of the input signal / in decreases, the voltage of the output of the function generator and accordingly, the output of the storage device increases. This increases the steepness of the fronts of the sawtooth voltage Ub, and its amplitude remains constant.

Similarly, when increasing the frequency / in, the amplitude of the output voltage t / 8 and the steepness of the voltage f / 5 edges are reduced. Setting the comparator level of the comparator and the inverter transmission coefficient according to the required phase shift, the relative duration of the front and rear edges of the sawtooth voltage can be changed.

Since for charging and discharging the storage capacitor of the sawtooth generator, the same voltage t / 8 is supplied from the memory output, the accuracy of the phase shift is determined only by the stability of the inverter and switch gear ratios, and little

depends on changes in the characteristics of other circuit elements.

The response time of the switch that connects the sawtooth voltage to the input of the generator, either positive or negative, does not depend on the duration of the control pulses, but only the duration of the leading edges is determined, THAT allows you to dramatically expand the frequency range.

Subject invention

A device for obtaining a sawtooth voltage, comprising a pulse shaper, a sawtooth voltage generator, an adder, a key, a function generator and a memory device, characterized in that, with a slot for increasing accuracy and expanding the frequency range, it is equipped with a switch, a comparator

and an inverter, the device input through a pulse shaper connected to a switch, a key and through a function generator with an adder, the second input of which is connected to the output of the saw voltage generator and the input of a comparator, the output of which is connected to the switch, and the output of the adder via a key connected to a device that is directly and via an inverter connected to a switch.

FIG. one

FIG. 2