Browse Prior Art Database

Oscilloscope Voltage Reference System

IP.com Disclosure Number: IPCOM000075472D
Original Publication Date: 1971-Sep-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Geib, WE: AUTHOR [+2]

Abstract

The system provides measurements with an oscilloscope to or from a point on a waveform 10 referenced to a chopped level positioned at will on the oscilloscope face, by a predetermined externally applied reference voltage Vref.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 92% of the total text.

Page 1 of 2

Oscilloscope Voltage Reference System

The system provides measurements with an oscilloscope to or from a point on a waveform 10 referenced to a chopped level positioned at will on the oscilloscope face, by a predetermined externally applied reference voltage Vref.

The scope sweep output voltage 12 is differentiated by first differentiator 14 at time t0 and inverted to produce a first trigger pulse 16, which is applied to first variable-width single-shot multivibrator 18 having an output voltage pulse 20. Trailing edge of voltage pulse 20 is then differentiated by second differentiator 22 at time t(1) and inverted to produce a second trigger pulse 24, which is applied to second variable-width single-shot multivibrator 26 having an output voltage pulse 28 applied to relay driver 30 which drives a reed relay 32 having a pair of coaxial switches 34, 36 speeded up through an RC network 38.

Adjustment of first single-shot multivibrator 18, i.e., the width of pulse 20, determines the location of the start of the chopped portion of waveform 10 on the oscilloscope face and the width of pulse 28 from second single-shot multivibrator 26 establishes the chopped width from t(1) to t(2). Switch 36 of relay 32 is normally closed to apply the input signal to the oscilloscope input, but during time t(1) to t(2) when pulse 28 is applied to relay driver 30, reed switch 36 is open and switch 34 is closed to apply the reference voltage Vref to the oscilloscope input. Measurement can...