DOUGLAS RICHARD POTRATZ
Pilots at Maricopa Dr, Oshkosh, WI

License number
Wisconsin A2211306
Issued Date
Nov 2015
Expiration Date
Nov 2017
Category
Airmen
Type
Authorized Aircraft Instructor
Address
Address
1319 Maricopa Dr, Oshkosh, WI 54904

Professional information

Douglas Potratz Photo 1

Cylinder-Specific Spark Ignition Control System For Direct Fuel Injected Two-Stroke Engine

US Patent:
5924404, Jul 20, 1999
Filed:
Oct 24, 1997
Appl. No.:
8/957144
Inventors:
Mark A. Ruman - Fond du Lac WI
Douglas R. Potratz - Oshkosh WI
Assignee:
Brunswick Corporation - Lake Forest IL
International Classification:
F02P 500
US Classification:
12340618
Abstract:
A direct fuel injected two-stroke engine controls spark ignition timing and/or ignition coil dwell time on a cylinder-specific basis. The engine also preferably controls fuel injection timing and amount and injection/delivery duration on a cylinder-specific basis. Cylinder-specific customization of spark ignition and fuel injection allows better coordination of spark with fuel injection which results in better running quality, lower emissions, etc. Memory in the electronic control unit for the engine preferably includes a high resolution global look-up table that determines global values for spark ignition and fuel injection control based on engine load (e. g. throttle position, manifold air pressure, etc. ) and engine speed. Memory in the electronic control unit also includes a plurality of low resolution, cylinder-specific offset value look-up tables from which cylinder-specific offset values for spark ignition and fuel injection can be determined, preferably depending on engine load and engine speed.


Douglas Potratz Photo 2

Ignition Coil Dwell Time Control System

US Patent:
5913302, Jun 22, 1999
Filed:
Sep 19, 1997
Appl. No.:
8/934475
Inventors:
Mark A. Ruman - Fond du Lac WI
Douglas R. Potratz - Oshkosh WI
Assignee:
Brunswick Corporation - Lake Forest IL
International Classification:
F02P 900
US Classification:
123609
Abstract:
A two-stroke direct fuel injected internal combustion engine has an ignition coil dwell time control system. An electronic control unit controls switching of electronic ignition coil drivers in a manner to minimize ignition coil dwell times at medium and high engine speeds where low ignition coil dwell times can be used without sacrificing engine performance. The electronic control unit also implements an intermittent spark plug cleaning strategy to remove carbon deposits from fouled spark plugs. Intermittent cleaning is accomplished during engine operation by periodically raising the ignition coil dwell time to an exaggerated cleaning level for a relatively short period of time (e. g. one minute) after it is determined the spark plug cleaning should occur (e. g. 10 to 20 engine operating hours since previous cleaning).


Douglas Potratz Photo 3

Stern Drive Marine Propulsion System With Automatic Trim Control And Exhaust Control

US Patent:
4960398, Oct 2, 1990
Filed:
Dec 28, 1988
Appl. No.:
7/291145
Inventors:
Douglas R. Potratz - Oshkosh WI
Assignee:
Brunswick Corporation - Skokie IL
International Classification:
B63H 2132
US Classification:
440 53
Abstract:
A stern drive marine propulsion system, including an exhaust discharge control mechanism for selectively routing exhaust to an above-water outlet and to a below-water outlet, and an automatic trim control mechanism, is provided with circuitry interconnecting such components. The trim control system and the exhaust control system are selectively interconnectable so that the exhaust control is actuated responsive to operation of the trim control system.