Oscilloscope used as an X-Y plotter or two-dimensional analyzer tags each point with a yes or no, depending on a third parameter. The usual square-wave pulse is replaced on the scope by a single information-bearing dot which lengthens to a dash in response to a simultaneous event

Hansen, D.

Roy, N.

English

NASA Technical Reports Server

August 1967	 Brief 67-10269 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Oscilloscope Used as X-Y Plotter or Two-Dimensional Analyzer 
Square-Wave Input Pulse 
Discriminator 1
	
Time Base 1 
I. 
Discriminator 2
	
Time Base 2
	
External Trigger 
Pulse from 
3rd Source	 Pulse Forming 
I 
Network 
Amplifier
Cathode of
Cathode-Ray Tube 
Pulse Stretcher
Oscilloscope 
Vertical 
Deflection 
An oscilloscope has been used as an X-Y plotter or 
two-dimensional analyzer with the capacity of 
tagging each point with a "yes" or "no", depending 
on a third parameter. A square-wave pulse that 
would normally appear on the scope is replaced by a 
single dot that appears at a point related to the ampli-
tude and horizontal position of the trailing edge of the 
input squire wave. The electronics design is such that 
the information-bearing dot lengthens to a dash in 
response to a second, and simultaneously occurring 
event. The length of this dash is adjustable relative to 
the sweep rate of the oscilloscope.
In operation, a square-wave pulse in a 50-ohm 
transmission line is applied to discriminator I. Input 
to all the components in the diagram exhibits a very 
high input impedance level compared to 50 ohms. 
Discriminator I fires at a selected level on the leading 
edge of the input 'pulse and triggers time base I. Dis-
criminator 2 and time base 2 perform similarly but in 
response to a selected level on the trailing edge of the 
input pulse. Output of time base 1 triggers the oscil-
loscope sweep circuit while output of time base 2 
triggers a pulse forming network that pulses the 
oscilloscope tube cathode. Should a pulse from a third 
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19670000269 2020-03-11T20:38:32+00:00Z
source appear at the second input to the pulse forming 
network, the pulse applied to the cathode by time base 
2 is lengthened by some adjustable amount. Following 
routing to the discriminators, the input pulse is 
applied to an amplifier and terminated in a 50-ohm 
load. Output of the amplifier is fed to a pulse stretcher 
having a time constant quite long compared to the 
oscilloscope sweep rate. The stretched pulse is applied 
to the vertical deflection circuit of the oscilloscope. 
Notes: 
I. When recorded photographically, the amount of 
data that can be distinguished per photograph is 
increased by at least two orders of magnitude 
over previous methods.
2. Inquiries concerning this innovation may be di-
rected to:
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B67-10269 
Patent status: 
No patent action is contemplated by NASA. 
Source: David Hansen and Neal Roy 
of TRW Incorporated 
under contract to 
Lewis Research Center 
(Lewis-31 I) 
Brief 67-10269
	
Category 01


Oscilloscope used as X-Y plotter or two-dimensional analyzer

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server