SU1205074A1 - Apparatus for converting static parameters of crystal vibrators - Google Patents

Description

one

The invention relates to a measurement technique and can be used to convert a static capacitance and an insulation resistance of a quartz resonator into a voltage.

The aim of the invention is to increase the speed of conversion

The drawing shows the structures on the device diagram.

The device contains a voltage source 1 connected in series, a quartz resonator 2 under investigation, an operational amplifier 3, a reference capacitor 4 connected to the feedback circuit of amplifier 3, an instantaneous meter 5, a subtracting unit 6, a comparator 7, and the first and second terminals 8 and 9 of the device for connecting a quartz resonator; and output terminals 10 and 11 of the device.

The device works as follows.

From the output of the source 1 of the reference voltage to the quartz resonator 2, the reference voltage Uo (t) is applied in the form of bipolar rectangular pulses of amplitude UQ. During each of the half periods of the reference voltage, the output voltage of the operational amplifier 3 (without taking into account the sign UQ

„(UoCcT Uo

Vo-j (t) + ----- t,

bgKui

WITH,

where C is the static capacitance of the quartz resonator; Ry- is the insulation resistance of a quartz resonator;

Compiled by L. Muranov Editor A. Lezhnin Tehred S. Migunova Proofreader L. Patay

Order 8523/47 Circulation 747 Subscription VNIIPIoState Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, Proektna St., 4

12050742

Cp is the capacitance of the reference capacitor.

The output voltage U of the meter 5 of the instantaneous value of the voltage of 5 that measures the value Uoy (t) at the initial moment of time is proportional to the static

capacity C .., and has the form

ten

UU.M (t)

WITH"

Output voltage and. subtraction unit 6

Up,. (T) and ,, (t) - U, "(t)

64

0

.T

 With

PP

Co R

Stock RUI

t Uo Ccr

- With

applied to one of the inputs of the comparator 7, to the other input of which the reference voltage Uo (t) is applied. At the moment of changing the sign of the difference of the input voltages (t) - Uo (t), the comparator 7 changes its state. A voltage pulse is generated at the output of the comparator 7, the duration g t c is determined from the condition UgyCt) - U (t) O. from where

A t Uo „and, OR

L

Lt C "K", the duration of the interval at the output terminal 11 of the device is proportional to the value of the insulation resistance of the quartz resonator. This interval is converted by simultaneously converting the static capacitance at the input terminal 10 of the device.

Claims (1)

DEVICE FOR CONVERTING STATIC PARAMETERS OF QUARTZ RESONATORS, containing a reference voltage output connected to the first terminal of the device for connecting the crystal oscillator under study, the second terminal of which is connected to the input of the operational amplifier, which is connected through the reference capacitor with a negative feedback circuit, which differs in order to improve performance, an instantaneous voltage meter, a subtracting unit and a comparator are introduced into it, while the output of the operating an amplifier through an instantaneous voltage value meter is connected to the first input of the subtracting unit, § being the first output of the device, the second input of the subtracting unit is connected to the output of the operational amplifier, and the output of the subtracting unit is connected to the first input of the comparator, the second input of which is connected to the output of the reference voltage source, and the output of the comparator is the second output of the device.