Browse Prior Art Database

Ignition Analysis Attachments

IP.com Disclosure Number: IPCOM000035910D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Kraus, RA: AUTHOR [+2]

Abstract

This article describes a technique for an automotive vehicle technician terminal to measure ignition sparks in an engine, thereby allowing diagnosis of some ignition system faults. (Image Omitted)

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 59% of the total text.

Page 1 of 2

Ignition Analysis Attachments

This article describes a technique for an automotive vehicle technician terminal to measure ignition sparks in an engine, thereby allowing diagnosis of some ignition system faults.

(Image Omitted)

The method of this disclosure makes use of special probes and a unique vehicle probe interface (VPI) to acquire secondary ignition voltage signals from ignition cable(s). Refer to the block diagram in Fig. 1 which shows the VPI and connections to a probe attachment card in the technician terminal through four probe lines. Lines labelled "+5V" and "GND" provide power and signal return for the circuitry on the VPI. The two remaining lines are "conditioned signal" and a tri- level analog "control" signal which provides "data ready" and "data ready with sync" information.

Two capacitively coupled clip-on probe cables are used to receive the signal. One probe is always connected to the #1 cylinder spark plug wire to establish synchronization of the test equipment with the ignition system firing sequence. The other probe is connected to the ignition coil secondary wire of the cylinder under test.

Fig. 2 is a block diagram of the VPI. During operation, the VPI samples input signals and retains the peak voltage readings in a sample-and-hold circuit. Analysis of peak voltage data, as delivered by the VPI circuit, will yield data relative to a specific cylinder, thereby allowing the state of the ignition system to be diagnosed.

The analog interface (...