Waveform searching system

• US 4,399,512 A
• Filed: 12/17/1980
• Issued: 08/16/1983
• Est. Priority Date: 12/27/1979
• Status: Expired due to Fees

• Current Assignee: Iwasaki Tsushinki Kabushiki Kaisha
• Original Assignee: Iwasaki Tsushinki Kabushiki Kaisha
• Inventors: Soma, Masafumi, Kohno, Yoshihiko
• Primary Examiner(s): Chin, Gary
• Application Number:
  US06/217,462
• Time in Patent Office: 972 Days
• Field of Search: 364/487, 364/521, 364/607, 364/851, 324/121 R, 324/102, 324/77 R, 340/715, 340/722
• US Class Current: 702/67
• CPC Class Codes: G01R 13/06 Modifications for recording transient disturbances, e.g. by starting or accelerating a recording medium
• CPC Class Codes: G01R 13/34 Circuits for representing a single waveform by sampling, e.g. for very high frequencies
• CPC Class Codes: G01R 15/09 Autoranging circuits
• CPC Class Codes: G01R 29/02 Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time or duration

Abstract

A waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time; the input analog signal is sampled by the sampling pulses to produce sampled pulses; and the sampled pulses are displayed by the X-axis sweep signal on a CRT. In accordance with the present invention, there are provided detecting means for detecting a predetermined condition where a waveform formed by respective peak values of the sampled pulses cross in a predetermined direction at a predetermined search level by a predetermined number; and control means for sequentially changing a time base range until the detecting means detects the predetermined condition, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.

Claims

1. In a waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time;

the input analog signal is sampled by the sampling pulses to produce sampled pulses; and

the sampled pulses are displayed by the X-axis sweep signal on a CRT, the improvement comprising detecting means for producing a coincidence signal if a predetermined condition is detected where a waveform formed by respective peak values of the sampled pulses crosses in a predetermined direction at a predetermined search level by a predetermined number; and

control means operatively connected to the detection means for sequentially changing a time base range of the CRT until said detecting means produces the coincidence signal, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.

2. In a waveform searching system for a sampling oscilloscope, in which the instantaneous level of a high-speed sawtooth signal generated by a trigger signal synchronized with an input analog signal and the instantaneous level of a properly attenuated or amplified X-axis sweep wave are compared with each other to generate a pulse in a case of coincidence therebetween, thereby to generate sampling pulses sequentially delayed after the trigger signal by a constant time;

the input analog signal is sampled by the sampling pulses to produce sampled pulses; and

the sampled pulses are displayed by the X-axis sweep signal on a CRT, the improvement comprising detecting means for producing a coincidence signal if a predetermined condition is detected where a waveform formed by respective peak values of the sampled pulses cross in a predetermined direction at a predetermined search level by a predetermined number; and

control means operatively connected to the detection means for sequentially changing a time base range of the CRT determined by the inclination of the high-speed saw-tooth signal and the amplitude of the X-axis sweep voltage wave until the detecting means produces the coincidence signal, whereby the sampled pulses having the predetermined condition are automatically displayed on the CRT.