PL150326B1 - Calibration system capable to exclude ac operation - Google Patents

Description

PATENT DESCRIPTION

150 326

OFFICE

PATENT

RP

Additional patent to patent no. Applied: ®7 04 07 / P. 265039 /

Priority C 2 Y i e L NIA

U '* »► *» »». _ua

Int. Cl. ⁵ G01R 13/22

Application announced: ^{88 02}

Patent description published: 1990 10 31

Inventor: Jerzy Rydzewski

Entitled by the patent: Zakłady Maszyn i Urządzeń Technologicznych UNITRA-UNIMA Zakład Urządzeń Elektronicznych, Warsaw / Poland /

CALIBRATOR CIRCUIT WITH CURRENT CURRENT OPERATION

The subject of the invention is a calibrator circuit with an AC cutout used in electronic oscilloscopes.

In the calibrator systems known so far, such as the one used in the 0S-710 oscilloscope from UNITRA-UNIMA in Warsaw, the alternating voltage generator controls the base of the output transistor, in the collector circuit of which there is a resistor voltage divider. At the output of this system, an alternating voltage in the shape of a square wave is obtained. The square wave peak-to-peak value cannot be checked with standard reference voltmeters, as they are only rated for sinusoidal voltages.

In order to be able to adjust and control the calibrator's output voltage, instead of measuring the ac voltage, a dc voltage is measured equal to the peak value of the square wave with a precision digital dc voltmeter. Carrying out such a measurement requires entering the oscilloscope and interrupting the operation of the alternating voltage generator. The above operation is troublesome, time-consuming and increases the cost of operating the device.

The circuit according to the invention is characterized in that the base of the output transistor is additionally connected via a first resistor to the first contact of the switch, the second contact of which is grounded.

The advantage of the system according to the invention is that the output of a DC voltage calibrator is obtained, the value of which can be easily checked at any time with a digital voltmeter, and moreover, this voltage can be used as a reference DC voltage reference source. Moreover, the implementation of the discussed system is cheap, since it is required to fulfill this function

150 326, you can use free contacts of one of the oscilloscope switches that fulfill their basic function other than changing the type of calibrator operation.

The invention is explained in more detail in the embodiment shown in the drawing, which is a schematic diagram of a calibrator system.

The output of the generator G is connected to the base of the output transistor T and, through a first resistor R1, to the first contact of the switch P, the second contact of which is connected to ground. The collector of the output transistor T is connected via series connected resistors R1 and second R2 to ground. The common point of these resistors is connected to the output terminal Wy. The emitter of the transistor T is connected to the lower pole of the power source + U.

Under normal working conditions of the calibrator, the contacts * of the P switch are open and the desired calibration alternating voltage is obtained at the output terminal Wy, at the frequency of the G generator. regulation of direct voltage value. After adjustment and measurement of DC voltage, the system is restored to its original state by opening the P switch contacts.

Claims (1)

Patent claim Calibrator circuit with switching off AC operation j containing an alternating voltage generator controlling the base of the output transistor, in the collector circuit of which there is a resistor voltage divider, characterized in that the base of the output transistor / T / is additionally connected through the first resistor / R1 / with the first switch contact / P /, the second contact of which is connected to the ground. Department of Publishing of the UP RP. Circulation 100 copies Price 1500 PLN