Measuring and testing – Engine detonation
Patent
1994-10-11
1996-01-16
Wieder, Kenneth A.
Measuring and testing
Engine detonation
324393, 324123C, 324609, 324688, 324399, 73 3508, G01L 2322, G01N 2520
Patent
active
054838185
ABSTRACT:
A method and a circuit are provided for detecting low level ionic currents. An ionization detection voltage is applied to a spark plug and a resulting output voltage signal is sent to a threshold device. The output voltage signal is developed by a low offset operational amplifier. First and second serially connected Zener diodes carry current in a normal diode direction when a spark event occurs and carry current in their Zener breakdown mode upon recovery from the spark event. A second operational amplifier and its associated feedback circuit generate a guard voltage which is applied to the junction of the two Zener diodes. The guard voltage is regulated to track the input voltage to the circuit at the cathode of the first diode. Because the guard voltage is essentially the same as the input voltage, there is no leakage current flow through the first diode. Consequently, the output voltage signal developed at the threshold device is attributable exclusively to ionization current and very low signal levels can be detected. The resulting signal from the threshold device is utilized in detection logic with other vehicle signals to provide a misfire output signal to detect misfires.
REFERENCES:
patent: 4270090 (1981-05-01), Williams
patent: 4515132 (1985-05-01), Anderson et al.
patent: 4648367 (1987-03-01), Gillbrand et al.
patent: 4670663 (1987-06-01), Fancher
patent: 4719409 (1988-01-01), Dorman
patent: 4862093 (1989-08-01), Jiewertz
patent: 5087882 (1992-02-01), Iwata
patent: 5180984 (1993-01-01), Murata et al.
patent: 5207200 (1993-05-01), Iwata
patent: 5221904 (1993-06-01), Shimasaki et al.
Danyluk: "A UHV Guarded Kelvin Probe"-Journal of Scientific Instruments-Mar. 1972.
Brandt Arnold W.
Bucciarelli Robert B.
Jones, III Thomas E.
Ford Motor Company
Lippa Allan J.
May Roger L.
Solis Jose M.
Wieder Kenneth A.
LandOfFree
Method and apparatus for detecting ionic current in the ignition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for detecting ionic current in the ignition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for detecting ionic current in the ignition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-301992