SECONDARY WAVEFORM ANALYZER

• US 3,793,583 A
• Filed: 09/08/1970
• Issued: 02/19/1974
• Est. Priority Date: 09/08/1970
• Status: Expired due to Term

• Current Assignee: Arthur F. Glomski, Sol Baum
• Original Assignee: Arthur F. Glomski, Sol Baum
• Inventors: Glomski, Arthur F., Baum, Sol
• Primary Examiner(s): Lynch, Michael J.
• Application Number:
  US05/070,585
• Time in Patent Office: 1,260 Days
• Field of Search: 324/15,16,121,16S,16T,169,170 73/116-119
• US Class Current: 324/402
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing

Abstract

An analyzer which detects and displays on a cathode ray tube secondary voltage waveforms of internal combustion engines and the like with no physical connections required to be made to the engine under test, the coupling being accomplished by a remote pick-up such as a directional antenna or a proximity probe. The analyzer is provided with an extraordinarily high input impedance in order to be able to detect the radiated signal, which has an extremely low current component.

Claims

1. A system for use in the analysis of internal combustion engine ignition systems or the like, comprising:

radiation detecting means for remotely detecting signals indicative of engine performance radiated by the secondary circuit of the ignition system, said detecting means in use being located near but spaced apart from and out of contact with said ignition system or said engine, said detecting means comprising a capacitive probe in the form of a fixed plate and over which a vehicle including such engine may pass for analysis;

means for converting said signals into a waveform representing the electrical performance of said secondary circuit and display means coupled to said converting means for visually displaying said waveform; and

coupling means for coupling said detecting means to said converting means.

2. A system of the type described in claim 1 wherein said coupling means comprises buffering means, amplifying means, and signal amplitude control means.

3. A system of the type described in claim 1 wherein said coupling means comprises buffering means, said buffering means having an input impedance on the order of 109 ohms.

4. The system set forth in claim 3 wherein said buffering means has impedance means coupled to the input thereof and comprising a metal oxide silicon field effect transistor, the gate electrode of said transistor being coupled to said detecting means.

5. A system for rapid and simple analysis of an internal combustion engine ignition system of an automotive vehicle while adjacent the fuel pumps of a service station for conventional fueling and associated services, comprising:

probe means responsive to high voltage, low power radiation from the entirety of the secondary circuit of said ignition system for providing a signal indicative of engine operating condition, said probe means being located near to but being spaced from and free of physical contact with said ignition system when the vehicle is adjacent said fuel pumps, said probe means being located adjacent said fuel pumps;

an analyzer device at one of said fuel pumps and having a visible cathode-ray tube for displaying a waveform depicting performance of the ignition system secondary circuit of the adjacent vehicle, said analyzer device including input buffer means connected to said probe means and having a high input impedance in the region of 109 ohms for preventing distortion of said signal received from said probe means despite the low power of such radiation, said input buffer means having first and second outputs;

circuit means connecting said first and second outputs to said cathode-ray tube for causing a display thereon corresponding to the operating condition of the ignition secondary circuit of the vehicle being serviced;

whereby the fuel pump attendant can evaluate such operating condition while carrying out fueling and associated routine services on the vehicle at the fuel pumps and without removing the vehicle from the fuel pump area.

6. A system of the type described in claim 5 wherein said circuit means includes:

an external gain control circuit and a vertical deflection amplifier connected in series from said first output to the deflection yoke of said cathode-ray tube;

pulse shaper means connected to said second output for converting said signals to logic signals and a binary counter driven by said logic signals;

attendant controlled information circuit means responsive to the number of cylinders of the engine of the adjacent vehicle and connected to said binary cOunter for controlling cycling of said binary counter, said binary counter having a pair of outputs.

7. A system of the type described in claim 6 wherein said circuit means further includes:

a horizontal sweep circuit connected to one of said outputs of said binary counter and a horizontal deflection amplifier connecting an output of said horizontal sweep circuit to said cathode-ray tube;

blanking pulse circuit means connected to another output of said horizontal sweep circuit and responsive to the other of said binary counter outputs for generating a blanking pulse for each binary counter count corresponding to the number of cylinders of the adjacent vehicle engine, said blanking pulse circuit connecting to said cathode-ray tube;

said probe means comprising a directional antenna mounted at least in close adjacency to said analyzer device and directed toward the engine compartment of the vehicle adjacent said fuel pumps.

8. A system of the type described in claim 6, wherein said probe means comprises a directional antenna.

9. A system of the type described in claim 6, wherein said probe means comprises a proximity probe responsive to electromagnetic radiation to produce electrical signals when placed in proximity to said engine.